RU2353301C2 - Pancreatic cancer and chronic pancreatitis differential diagnostic technique - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to endoscopic ultrasonic diagnostics, and covers differential diagnostics of pancreatic cancer and chronic pancreatitis. The results of pancreas endosonography show the criteria of focal growth morphology with values to be scored. Diagnostic factor D is calculated by formula D=0.53246+0.21578×C-0.048315×K+0.24554×P+0.18461×O, where K, P, O are values (number of points) of the present morphology criteria, C is a value (number of points) of focal Y- and X-dimensions ratio derived from arithmetical difference of actual and expected Y-dimensions of focal growth. The expected Y-dimension is calculated thus predicted vertical size under the formula: Y=4.1795+0.43873×X. If D is <1.5, pancreas cancer is diagnosed. If D is ≥1.5, chronic pancreatitis is diagnosed.

EFFECT: more accurate differential diagnostics of pancreatic cancer and chronic pancreatitis.

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Description

The invention relates to medicine, namely to oncology, surgery, endoscopic ultrasound diagnostics.

For the differential diagnosis of pancreatic diseases, various examination methods have been proposed, such as transcutaneous ultrasound, computed tomography, ERCP, radial scanning endosonography, convex endosonography with puncture biopsy.

Ultrasound is easy to use, non-invasive, there is equipment in every medical institution, however, the accuracy of conventional ultrasound diagnostics is not too high due to the complex location of the pancreas, artifacts from the adjacent loops of the intestine and stomach. The accuracy of ultrasound for pancreatic cancer and for chronic pancreatitis is 73.3% and 76.2%, and the sensitivity is 71.7% (Danilov M.V., Fedorov V.D. Pancreatic surgery: A guide for doctors. M .: Medicine, 1995 - 512 p.).

Computed tomography allows a non-invasive method to obtain an image of a pathological lesion in the pancreas, computed tomography devices are also becoming more accessible. However, problems remain in the recognition of pancreatic tumor lesions and the differentiation of the latter from pseudotumor pancreatitis. This is due to the absence of large differences in the radiological density between the tumor tissue and the parenchyma, when you have to focus on changing the shape and contours of the pancreas, the absence of parapancretic fatty layers. In general, the accuracy of diagnosis of cancer of the head of the pancreas reaches 84%, and the body and tail - up to 96%, but only in the case of a developed tumor (Todua F.I. et al. Computed tomography of the abdominal organs (Atlas) / USSR Academy of Medical Sciences. - M .: Medicine, 1991, 448 p.). The use of computed tomography leads to radiation exposure of the patient.

Endoscopic retrograde cholangiopancreatography makes it possible to differentiate between pancreatic tumors and chronic pancreatitis with an accuracy of 90% (Danilov M.V., Fedorov V.D. Pancreatic Surgery: A Guide for Doctors. - M .: Medicine, 1995 - 512 p.). However, retrograde contrast of the bile duct and pancreatic ducts significantly increases the possibility of complications such as cholangitis, acute pancreatitis, up to pancreatic necrosis, rupture of the main pancreatic duct, suppuration of the pancreatic cysts. Conducting ERCP leads to irradiation of both the patient and the staff performing the study.

One of the methods of non-invasive differential diagnosis of pancreatic cancer and chronic pancreatitis is endoscopic ultrasonography (ESM). (Role of EUS in the evaluation of pancreatic adenocarcinoma. Maurits J. Wiersema, lan D. Norton, Jonathan E. Clain. Gastrointestinal Endoscopy. 52 No. 4 October 2000). The greatest difficulties arise in the differential diagnosis of cancer and chronic pancreatitis (primarily pseudotumorous). In this situation, both overdiagnosis and underestimation of the pathology can lead to serious consequences: performing unnecessary expanded pancreato-duodenal resection for pancreatitis, which can be treated conservatively, or the patient’s death in an undiagnosed tumor process without surgical treatment (Incidence and clinical findings of benign, inflammatory disease in patients resected for presumed pancreatic head cancer. Thomas M. van Gulik, Jacques WAJ Reeders, Anne Bosma, Thybout M. Moojen, Nico J. Smits, Jan Hein Allema, Eric AJ Rauws, G. Johan A. Offerhaus, Huug Obertop, Dirk J. Gouma, Gastrointestinal Endoscopy 46 • Number 5 • November 1997).

The anatomical location of the pancreas determines objective difficulties in obtaining material for morphological verification of the diagnosis, often the tumor develops against the background of previous pancreatitis, or the development of cancer leads to a secondary change in the surrounding parenchyma [Differential diagnosis of focal pancreatitis and pancreatic cancer, van Gulik TM, Moojen TM, van Geenen R, Rauws EA, Obertop H, Gouma DJ Ann Ital Chir 1999 Mar-Apr; 70 (2): 217-22]. This leads to additional difficulties, distorting the characteristic endosonographic picture and changing the clinical course of the disease.

Closest to the proposed is a method in which endosonographically a pancreatic tumor is described as a focal heterogeneous formation of irregular shape, often of reduced echogenicity, with fuzzy contours. Pancreatitis is more characterized by a homogeneous lesion of rounded echogenicity with distinct borders ["The handbook of endoscopic ultrasonography in digestive tract", Kenjiro Yasuda, First Edition, 2000, Blackwell Science Japa K.K., 152 p.].

However, all known methods are not highly informative in the differential diagnosis of pancreatic cancer and chronic pancreatitis.

The technical result of the proposed method is to increase the information content and accuracy of differential diagnosis.

New in achieving the technical result is that during the study, the ratio of the horizontal and vertical size of the lesion (C), the presence of a pancreatic pattern in the lesion (P), the contour of formation at the site of contact with the common bile duct and the Wirsung duct (K) and a criterion that includes assessment of the presence or absence of the focus and uniformity of the surrounding pancreatic parenchyma (O), and calculate the diagnostic coefficient according to the formula.

What is also new is that with a ratio of <1.5, pancreatic cancer is diagnosed, and with a ratio of ≥1.5, chronic pancreatitis is diagnosed.

The method is the result of a retrospective study in which 153 patients were included: 96 patients with pancreatic cancer and 57 patients with pancreatitis.

The criterion for inclusion in the study was the presence of focal and diffuse changes in the pancreatic parenchyma.

The exclusion criteria were: 1) the inability to assess the state of the parenchyma of the entire pancreas due to previous resections of the stomach by Billroth-2 or gastrectomy, as well as duodenal stenosis; 2) reliably established metastatic lesion of the pancreas; 3) an unknown histological diagnosis or outcome of the disease with a follow-up period of less than 2 years.

The vertical size of the focal formation in cancer was 29 (24-35) mm, in chronic pancreatitis - 22 (12-38) (p <0.05). The horizontal size of the focal formation was, respectively, 39 (30-48) and 33 (25-43) (p> 0.1). A significant nonparametric correlation was revealed between the vertical and horizontal sizes of the focal formation both in chronic pancreatitis and in cancer, however, the correlation coefficients differed and amounted, respectively, to 0.69 (p <0.001) and 0.9 (p <0.01). The revealed differences show that the ratio of vertical and horizontal sizes with focal formation of the pancreas is an independent value and can characterize the nosological form of the disease. In this case, the form of a pancreatic cancer is closer to spherical, and the form of focal lesion in pancreatitis is closer to ellipsoid.

For verification, a mathematical analysis was performed based on a quantitative assessment of the most stable correlation - the relationship between the vertical and horizontal sizes of focal formation in chronic pancreatitis (Figure 1).

Thus, the predicted vertical size for chronic pancreatitis is calculated by the formula 1:

Y = 4.1795 + 0.43873 · X,

where Y is the predicted vertical size, mm,

X - real horizontal size, mm.

Comparison of the predicted vertical size of the focal formation, calculated according to the presented formula 1, for cancer and chronic pancreatitis confirmed the results of the correlation analysis. The arithmetic difference between the real and the predicted indicator is presented in figure 2.

In chronic pancreatitis, the prognosis error (or arithmetic difference between the real and predicted vertical lesion sizes) was on average 0 mm (with quartiles from - 1 to 2 mm), and for pancreatic cancer, the prognosis error was on average 8 mm (when the value quartiles from 3 to 12 mm). The data presented make it possible to use the ratio of the vertical and horizontal sizes of the focal formation within the 95% confidence interval in the differential diagnosis of pancreatic cancer and chronic pancreatitis.

Thus, with an arithmetic difference of the actual vertical size and the one predicted by the presented formula, we consider the detected formation as a focus of chronic pancreatitis ≥3 mm and assign 1 point (see table 1), with a difference of ≤2 mm - we consider the detected formation to be of a tumor nature and assign 2 points (see table 1).

A comprehensive assessment of the structure of the parenchyma, taking into account the presence or absence of focal changes, showed a significant prevalence of a sign of a homogeneous structure with a focal change in pancreatic cancer, a sign was detected in 87 (92%) patients. In chronic pancreatitis, this symptom was detected in 9 (16%) patients (p <0.001).

For chronic pancreatitis, the presence of a heterogeneous parenchyma without focal changes was more characteristic. The symptom was detected in 25 (44%) patients with chronic pancreatitis and not a single patient with pancreatic cancer (p <0.001).

In chronic pancreatitis, pancreatic pattern was observed throughout the gland, including focal formation in 34 of 57 patients (59.65%), was doubtful in 20 of 57 (35.1%), was not visualized in 3 of 15 (5.26%) . In case of pancreatic cancer in the focal area, pancreatic pattern was doubtful in 16 of 96 patients (16.7%) and did not differentiate in 79 of 96 (82.29%); it was visualized in a parenchyma with undetected pancreatic cancer in one patient (1, 04%). Thus, the presence of pancreatic pattern in chronic pancreatitis is much more common than in pancreatic cancer (p <0.001), and this symptom can be attributed to the differential diagnostic criteria.

In case of tumor lesion of the pancreas, in the case of clear visualization of the contact between the tumor and the common bile duct or Wirsung duct, in half of the cases we observed tumor invasion into the lumen of the ducts in the form of small tuberous bulges or even quite large fragments of tumor tissue in the duct (47 out of 96 - 49%). The contour of the duct was chopped off. The identified sign had high statistical significance (p <0.001).

In case of chronic pancreatitis (5 out of 57 - 8.7%) and in some cases of cancer of the gland (10 out of 96 - 10.4%), compression of the common bile duct without signs of invasion could be observed.

The authors first established that the ratio of the horizontal and vertical size of the focal formation, the criterion for assessing the presence of the lesion and the homogeneity of the surrounding pancreatic parenchyma, the contour of the focal formation at the site of contact with the bile duct and pancreatic ducts and the presence or absence of pancreatic pattern in the lesion are characteristic features, the combination of which allows you to accurately differentiate focal pancreatitis or pancreatic cancer without morphological and repetition.

Comparative analysis with the prototype shows that the inventive method is characterized in that in the study, the ratio of the vertical and horizontal size of the lesion (C), the contour of the formation at the site of contact with the common bile duct and the Wirsung duct (K), the presence of a pancreatic pattern (P) and the criterion are preliminarily determined , including an assessment of the presence or absence of the focus and uniformity of the pancreatic parenchyma outside the focal formation (O), and calculate the diagnostic coefficient D by the formula:

D = 0.53246 + 0.21578 × C-0.018315 × K + 0.24554 × P + 0.18461 × O, where

C is a numerical value (the number of points) for the ratio of the ratio of the vertical and horizontal size of the lesion, which is determined by the arithmetic difference of the real and predicted vertical sizes of the focal formation, while the predicted vertical size is calculated by the formula:

Y = 4.1795 + 0.43873 × X, where

Y is the predicted vertical size of the focal formation, mm,

X is the actual horizontal size, mm, while:

- the arithmetic difference of the real and predicted vertical dimensions of the focal formation is greater than or equal to 3 mm - 1 point,

- the arithmetic difference of the real and predicted vertical dimensions of the focal formation is less than or equal to 2 mm - 2 points;

K is the numerical value (number of points) for the formation contour at the site of contact with the common bile duct and the Wirsung duct:

- not visualized - 0 points,

- the lumen is squeezed without growth - 1 point,

- fine tuberous growth - 2 points,

- large outgrowths - 3 points;

P is the numerical value (number of points) for pancreatic drawing in the focus:

- no - 1 point,

- doubtful - 2 points,

- yes - 3 points;

О - numerical value (number of points) for the criterion, including an assessment of the presence or absence of the focus and heterogeneity of the pancreatic parenchyma outside the focal formation:

- homogeneous structure with a focus - 0 points,

- heterogeneous structure with a focus - 1 point,

- a homogeneous structure without a focus - 2 points,

- heterogeneous structure without a focus - 3 points;

and with a coefficient of D <1.5, pancreatic cancer is diagnosed, and with a coefficient of D≥1.5, chronic pancreatitis is diagnosed. This meets the criterion of "novelty."

A new set of features allows you to expand the capabilities of the study, to increase the accuracy of differential diagnosis without increasing its invasiveness and cost, which meets the criteria of the invention of "industrial applicability".

The proposed method is illustrated by the following drawings and tables, in which Fig. 1 shows the relationship between the horizontal and vertical size of the focal pancreatic lesions in chronic pancreatitis, Fig. 2 shows the arithmetic difference between the real and predicted vertical focal lesions in cancer and chronic pancreatitis, calculated according to formula 1, table 1 gives a score of signs used to calculate the coefficient of differential diagnosis of pancreatic cancer of pancreatitis and chronic pancreatitis, Table 2 presents the regression model for the differential diagnosis of pancreatic cancer from chronic pancreatitis based on the ESM symptoms obtained in the Statistica 6.0 program, Table 3 shows the diagnostic coefficient characteristic of the nosological affiliation of the lesion, Figure 3- Figure 9 shows endosonographic photographs of focal lesions in pancreatic cancer and pancreatitis, illustrating clinical examples.

The method is as follows.

The research technique is fully consistent with standard endosonography of the pancreatobiliary zone (Standart imaging techniques in the pancreatobiliary region using radial scanning endoscopic ultrasonography. Kazuo Inui, Misuhiro Kida, Naotaka Fujita, Hiroyuki Maguchi, Kenjiro Yasuda, Kenji Yamao. Digestive Endoscopy, 2004, 16 Suppl., S 118 - S 133).

The study uses a GF-UM20 ultrasonic fibrogastroscope with an EU-M30 ultrasonic processing unit manufactured by Olympus Japan, mounted with an EVIS CV-140 video center, or a GF-UM160 ultrasonic video gastroscope with an EU-M60 ultrasonic center mounted with a CV-160 system video center EVIS EXERA, also produced by Olympus Japan. If there is a suspicion of focal pancreatic formation, a radially scanning echo endoscope is carried out into the descending branch of the duodenum, from where the head of the pancreas with surrounding vessels and bile ducts and pancreatic ducts passing in the parenchyma is examined. Rotating and tightening the echo endoscope sequentially, the choledoch to the gates of the liver, gall bladder and isthmus of the pancreas are examined from the duodenal bulb. By moving the end of the echo endoscope with an ultrasound probe into the body of the stomach, through its back wall, the body and tail of the pancreas are scanned.

When a focal lesion is detected, special attention is paid to its size, and the horizontal focal lesion size is considered oriented along the pancreas length parallel to the Wirsung duct, and accordingly perpendicular to the direction of the ultrasound rays of the echoendoscope sensor, and vertical - across the pancreas length, perpendicular to the Wirsung channel and beam sensor radial scanning echo endoscope.

Assess the condition of the surrounding parenchyma and the presence of the focus. A comprehensive criterion for the presence of a lesion and the structure of the surrounding pancreas describes the following 4 ratios: 1) the heterogeneous structure of the surrounding pancreas without a lesion, 2) the homogeneous structure of the surrounding pancreas without a lesion, 3) the heterogeneous structure of the surrounding pancreas with a lesion, 4) the homogeneous structure of the surrounding pancreas glands with a focus.

In focal formation, the presence or absence of pancreatic pattern is determined.

Upon contact of the focal formation with the ductal structures of the pancreas (bile duct and pancreatic ducts), special attention is paid to the shape of the border of the focal formation and duct. The contour of the bile duct and pancreatic duct at the site of contact with the focal formation can be squeezed by pancreatic tissue (or tumor) without sprouting into the duct, which forms a funnel-shaped narrowing. When a tumor grows into a duct, the contour at the site of duct contact becomes “chopped off”, fine tuberous bulges or even rather large fragments of tumor tissue in the lumen of the duct are visualized from the side of the tumor. In addition, echogenicity, uniformity or heterogeneity of the structure, the presence or absence of inclusions of increased or decreased echogenicity, as well as liquid (anechogenic) inclusions, are described in the focal formation. The contours of education (clear or blurry), even or uneven, are also evaluated. With uneven contours pay attention to what kind of unevenness - how much the “processes” or “protrusions” of the tumor swell, whether or not there is a hypoechoic rim around the tumor. The presence or absence of invasion of the neoplasm into the surrounding organs, large vessels, the presence, type and size of regional lymph nodes, the presence of free fluid in the abdominal cavity are determined.

In accordance with the regression coefficients, each feature is assigned a numerical value (score), the maximum value of which is correlated with the value of the regression coefficient (Table 1).

The analysis was performed in the Statistica 6.0 program by sequentially testing the relationship of endosonographic signs (ratio of the horizontal and vertical size of the focal formation, a comprehensive criterion for the presence of a lesion and uniformity of the surrounding pancreas, the shape of the bile duct and (or) pancreatic duct at the site of contact with the focal formation, and the presence or absence pancreatic pattern in the focus) and features of the morphological structure of the focal formation (cancer or chronic pancreas atit). The analysis used not a qualitative description of the characteristic, but their numerical values presented in table 1. The analysis sought to obtain a statistically significant regression model (p <0.05) with a maximum coefficient of multiregression (R) and determination (RI), which reflect the stability of the model. Regression coefficients (β) and their significance (p) were studied on the obtained model. The basis for constructing a mathematical model was considered the presence of a constant member of multiregression (at p <0.05), in our case its value is 0.53246. The summation of the products of the value of the multiregression term and its coefficient was made taking into account the sign of the coefficient (Table 2).

As a result of multivariate analysis, a formula for calculating the coefficient D of the differential diagnosis of pancreatic cancer and chronic pancreatitis is obtained

D = 0.53246 + 0.21578 · C-0.048315 · K + 0.24554 · P + 0.18461 · O (± 0.22666),

where C is the numerical value (number of points) for the ratio of the vertical and horizontal size of the lesion, which is determined by the arithmetic difference of the real and predicted vertical dimensions of the focal formation, while the predicted vertical size is calculated by the formula:

Y = 4.1795 + 0.43873 × X, where

Y is the predicted vertical size of the focal formation, mm,

X - real horizontal size, mm,

wherein:

- the arithmetic difference of the real and predicted vertical dimensions of the focal formation is greater than or equal to 3 mm - 1 point,

- the arithmetic difference of the real and predicted vertical dimensions of the focal formation is less than or equal to 2 mm - 2 points;

K is the numerical value (number of points) for the formation contour at the site of contact with the common bile duct and the Wirsung duct:

- not visualized - 0 points,

- the lumen is squeezed without growth - 1 point,

- fine tuberous growth - 2 points,

- large outgrowths - 3 points;

P is the numerical value (number of points) for pancreatic drawing in the focus:

- no - 1 point,

- doubtful - 2 points,

- yes - 3 points;

О - numerical value (number of points) for the criterion, including an assessment of the presence or absence of the focus and heterogeneity of the pancreatic parenchyma outside the focal formation:

- homogeneous structure with a focus - 0 points,

- heterogeneous structure with a focus - 1 point,

- a homogeneous structure without a focus - 2 points,

- heterogeneous structure without a focus - 3 points;

and with a coefficient of D <1.5, pancreatic cancer is diagnosed, and with a coefficient of D≥1.5, chronic pancreatitis is diagnosed.

Evaluation of the coefficient D differential diagnosis of pancreatic cancer and chronic pancreatitis by the proposed formula is carried out according to the data in table 3.

The accuracy of the proposed formula is 94.12%, sensitivity 97.92%, specificity 87.72%, PCR 91.26%, PCR 96.15.

Clinical example 1.

Patient B., 61 years old, was hospitalized at City Clinical Hospital No. 1 of Irkutsk on 03/03/03 with complaints of weakness, weight loss, malaise, and yellowness of the skin. On ultrasound from 04.11.04, a volumetric formation in the projection of the head of the pancreas up to 4 cm in diameter, expansion of the common bile duct up to 17-20 mm, expansion of the Wirsung duct to 4-5 mm in the projection of the body of the gland, an increase in the size of the gallbladder were found. Under ultrasound control, a microcholecystostomy is applied. On endoscopy revealed an increase in the size of the BDS without expanding the longitudinal fold, a tumor of the BDS was suggested.

On November 13, 2003, a CT scan of the abdominal cavity was performed at the ICRC. In the study, the gallbladder collapsed, in the lumen of the drainage tube. Pancreas: head up to 30 mm, body 16 mm, tail 18 mm, homogeneous structure, native parenchyma density of about 45 N, pathological densitometry fields not determined. Spleen of medium size, homogeneous, native density of the parenchyma 63 N, fields of pathological densitometry not determined. In the retroperitoneal space, additional formations enlarged by l / nodes are not visualized. After I / O amplification (ultravist-370, 60 ml), the zone of interest (pancreas) was scanned in high definition mode (X-ray beam thickness 5 mm, table index 5 mm, reconstruction index 3 mm), the above organs uniformly accumulate contrast, parenchyma density the pancreas evenly rises to 95 N, the Wirsung duct throughout is expanded to 6.3 mm, the distal choledoch is up to 8.3 mm, the proximal choledoch is up to 13.2 mm, in the area of the large duodenal papilla, a volumetric formation merges with the image Podge head. glands, 22 mm in size, with a contrast density of up to 91 N. Exudation in the scan area is not visible. Conclusion: CT picture of a tumor of the large duodenal papilla. An endo-ultrasound of the pancreatobiliary zone in the IODC is recommended.

The patient was transferred to the Irkutsk Regional Oncology Dispensary, from where he was sent for endosonography of the pancreatobiliary zone in the IHRC.

12/01/03, endosonography of the pancreatobiliary zone was performed under intravenous anesthesia.

The echoendoscope GF-UM20 is freely carried out into the stomach, then with technical difficulties into the bulb and the descending branch of the duodenum. In the lumen of the stomach, mucus without admixture of bile. In the duodenum, moderate deformation of the lumen is noted due to wall infiltration in the projection of the bulb and the upper bend, where there is a hyperemic bulging area with a modified mucous relief up to 1.5 × 2 cm. The folds of the mucosa converge to elevation and are not visible in its projection. BDS is 2 cm below the bulging, the mucosa in its projection is moderately edematous, bile flow is not observed. The pancreatobiliary zone was scanned from the standard positions of the echo endoscope.

Bile ducts are visualized from the intrapancreatic part to hepatic choledochus. The width of the common bile duct in the intrapancreatic part is up to 18 mm. Here, the choledoch abruptly breaks off, has fine tuberous bulging into the lumen from the side of the hypoechoic formation, which will be described below (Figure 3, bulging is indicated by arrows). Intrahepatic ducts are moderately dilated.

Vater papilla in size is not increased, up to 9.0 × 4.7 mm, tissue of reduced echogenicity, pancreatobiliary fusion is not reliably visualized, the duodenal muscle layer is clearly visible.

The gallbladder is not enlarged, (40 × 13 mm), a drainage tube is visualized in the lumen, the walls are thickened to 4 mm.

The pancreas is slightly increased in size in the region of the head (up to 36 mm) due to a markedly heterogeneous field of slightly reduced echogenicity, with small (up to 1 mm) anechogenic inclusions, which is located in the projection of the distal choledochus. The horizontal size of the hypoechoic field is 36 mm, the vertical is 32 mm (Figure 3. The boundaries are marked with crosses). The contours are indistinct, blurry, uneven, jagged, in some scans with a hypoechoic rim. Normal pancreatic pattern in the field of education is not traced. The formation is adjacent to the portal vein, deforms its lumen, without preserving the hyperechoic layer of the vessel wall, it is located far from the superior mesenteric vein. Thickening, infiltration, and decreased echogenicity of the duodenal wall in the area of contact of the formation in the projection of the upper bend are noted. The contours of the pancreas in the remaining departments are clear, uneven, the echostructure is preserved, the parenchyma is homogeneous, fine-grained, of normal echogenicity (Figure 4 - the body of the pancreas).

The Wirsung duct in the terminal section is not traced, proximal to the formation up to 6 mm, in the body and tail up to 5-4-3 mm. The course of the duct is convoluted. In the lumen of the duct, additional formations are not determined.

The parenchyma of the right and left lobes of the liver of the usual echostructure, isoechogenic, is not reliably determined in the scanning sections of the focal changes.

On the lower edge of the head of the gland, an enlarged isoechogenic rounded lymph node with dimensions up to 6 × 5.5 mm with even clear contours is visualized. Other enlarged lymph nodes in the pancreatobiliary zone, along the spleen vessels and in the area of the celiac trunk are not significantly visualized. Free abdominal fluid is not reliably detected.

According to the proposed method, the differentiation of the volumetric formation of the pancreatic head is carried out. Endosonographic symptoms were scored according to table 1.

1. The determination of the predicted diagnosis is carried out according to the formula for the dependence of the vertical and horizontal sizes of the focus. First, according to the formula Y = 4.1795 + 0.43873 · X, the predicted vertical size of the formation is determined. Y = 4.1795 + 0.43873.36 = 19.97378 mm, rounded - 20 mm.

Then the difference between the real vertical size of the formation and predicted by the presented formula is calculated. 32 mm - 20 mm = 12 mm.

The obtained arithmetic difference of the real and predicted sizes (or forecast error) was 12 mm, which is more than 3 mm, which is more typical for pancreatic cancer, therefore we assign 1 point to the value of the coefficient "C" in the formula for the differential diagnosis of pancreatic cancer from chronic pancreatitis.

2. The choledoch contour in the area of contact with the formation of "chopped off", with small tuberous bulging, the value of the coefficient "K" is 2 points.

3. There is no normal pancreatic pattern in the projection of education, so the value of "P" is 1 point.

4. The surrounding focus of the gland parenchyma is homogeneous, fine-grained, of normal echogenicity - the value of the coefficient "O" is 0.

5. Substitute the scores of the coefficients in the formula

D = 0.53246 + 0.21578 · C-0.048315 · K + 0.24554 · P + 0.18461 · O

D = 0.53246 + 0.215781-0.0483152 + 0.24554-1 + 0.18461.0 = 0.89715.

When comparing the obtained value of D = 0.89715 with the numerical values of table 3, it was determined that 0.89715 is less than 1.5, therefore, the presence of adenocarcinoma of the pancreatic head is more likely.

Conclusion: This echographic picture is typical for volumetric formation (cancer) of the pancreatic head, with the development of biliary and pancreatic hypertension, with signs of probable invasion into the portal vein, without signs of invasion into the superior mesenteric vein, with invasion into the duodenal wall, without reliable signs of metastasis, lymphadenopathy (T4Nl? Mx). Condition after the application of cholecystostomy.

After preoperative chemotherapy on February 11, 2004, the patient underwent expanded pancreatoduodenal resection in the Irkutsk Regional Oncology Center. In surgery, the tumor is radically removed. Postoperative diagnosis: clear cell highly differentiated adenocarcinoma of the pancreatic head T4NoMo IVa Art. Postoperative chemotherapy was performed. According to July 2006, the patient is alive.

Clinical example 2.

Patient F., 46 years old, was hospitalized at City Clinical Hospital No. 1 in Irkutsk with complaints of weakness, yellowness of the skin, and lack of appetite. Pain, no fever. Upon receipt, total bilirubin up to 527, direct 279, indirect up to 248 μmol / L.

The onset of this exacerbation is associated with an episode of alcohol abuse. Three years ago he suffered acute pancreatitis, complicated by a cyst of the pancreatic head, the cyst was drained under ultrasound control. After hospitalization, a cholecystostomy is imposed, jaundice is partially stopped.

On an ultrasound scan performed in 1 GKB, the liver was sharply enlarged by 7 cm, homogeneous, of increased echogenicity, and the ducts were enlarged. Gall bladder up to 130 × 45 mm (before the application of cholecystostomy). Choledoch up to 18 mm, in the terminal department it is difficult to exclude the presence of small hyperechoic inclusions. The pancreas is not enlarged, the contours are uneven, the structure is heterogeneous, with small hyperechoic inclusions, the Wirsung duct is expanded to 4 mm. There is no effusion. Ultrasound conclusion: hepatomegaly, biliary hypertension, choledocholithiasis, chronic calculous pancreatitis.

The patient is referred to the ESR of the pancreatobiliary zone to clarify the diagnosis.

03/27/2003 endosonography was performed under intravenous anesthesia.

The GF-UM20 echo endoscope was freely inserted into the stomach, then with technical problems due to deformation of the prepiloric department, into the bulb and the descending branch of the duodenum. The mucous membrane of the duodenal bulb and the descending branch is eroded, swollen.

The pancreatobiliary zone was scanned from the standard positions of the echo endoscope.

Bile ducts were examined by a fragment above the head of the gland for up to 20 mm. The width of the common bile duct in the fragment accessible for examination is up to 9-10 mm, its distal part adjacent to the head of the gland breaks off sharply, in the contact area it is finely tuberous (Fig. 5, bulges are marked by arrows). The wall of the ducts in the examined areas is slightly thickened, evenly three-layer. The intrahepatic ducts are dilated.

Vater papilla is not enlarged, the duodenal muscle layer is clearly visible, pancreatobiliary duct connection at the level of the papilla itself.

The gall bladder is visualized by a fragment in the neck, the wall of the usual echostructure is slightly thickened, up to 2-3 mm, its structure is clear, the layers are differentiated, hyperechoic inclusion up to 5 × 3 mm with an acoustic shadow is not clearly visible in the bladder cavity.

It is difficult to evaluate the size of the pancreas in all departments, because the parenchyma contains multiple hyperechoic inclusions of various sizes (from 1-2 to 6-8 mm), almost completely covering the gland tissue with its shadows, its contours are not clear, uneven, the echostructure is changed, the parenchyma is inhomogeneously reduced echogenicity, against this background there are still lower echogenicity, in the remaining sections the usual "pancreatic" echo pattern is enhanced (Fig.6 - the area of the body of the gland with calcifications). In the head of the gland, against the described background, a more homogeneous hypoechoic lesion with uneven, jagged contours, with a horizontal size of up to 24 mm, vertical up to 23 mm, also with small hyperechoic inclusions is visualized in the region of entry of the common bile duct (Figure 5. The boundaries of the hypoechoic lesion are marked with crosses) . The usual pancreatic pattern in the area of the hypoechoic focus is not traced.

Wirsung duct with a width of up to 2-3 mm is visualized by fragments in the body of the gland. In the remaining sections, the shadows of calculi overlap it.

The parenchyma of the right and left lobes of the liver of the usual echostructure, isoechoic, pathological formations in the sections accessible to scanning are not determined.

In the hepatobiliary ligament, near the neck of the gallbladder, a lymph node enlarged to 12.3 × 19.6 mm of reduced echogenicity with smooth, clear contours is located. Other lymph nodes in the pancreatobiliary zone, along the splenic vessels and in the area of the celiac trunk are not enlarged. Free fluid in the abdominal cavity is not detected.

According to the proposed method, the differentiation of the volumetric formation of the pancreatic head is carried out. Endosonographic symptoms were scored according to table 1.

1. The determination of the predicted diagnosis is carried out according to the formula for the dependence of the vertical and horizontal sizes of the focus. First, according to the formula Y = 4.1795 + 0.43873 · X, the predicted vertical size of the formation is determined. Y = 4.1795 + 0.43873.24 = 14.70902 mm, rounded - 14.7 mm.

Then the difference between the real vertical size of the formation and predicted by the presented formula is calculated. 23 mm - 14.7 mm = 8.3 mm.

The obtained difference between the real and predicted sizes (or forecast error) was 8.3 mm, which is more than 3 mm, which is more typical for pancreatic cancer, so we assign 1 point to the value of the coefficient "C" in the formula for the differential diagnosis of pancreatic cancer from chronic pancreatitis.

2. The contour of the common bile duct in the area of contact with the formation of "chopped off", with small tuberous bulging, the value of "K" is 2 points.

3. There is no normal pancreatic pattern in the projection of education, so the value of the coefficient "P" is 1 point.

4. The surrounding focus of the parenchyma of the gland is heterogeneously reduced echogenicity, against this background there are areas of even lower echogenicity, in the remaining sections the usual "pancreatic" echo pattern is enhanced. In the head and body of the gland there are multiple calcifications with sizes ranging from 1-2 to 6-8 mm, giving an acoustic shadow, the value of the coefficient "O" is 1.

5. Substitute the scores of the coefficients in the formula

D = 0.53246 + 0.21578; C-0.048315; K + 0.24554; P + 0.18461; O

D = 0.53246 + 0.215781-0.0483152 + 0.245541 + 0.184611 = 1.11293

When comparing the obtained value of D = 1.11293 with the numerical values of table 3, it was determined that 1.11293 is less than 1.5, therefore, the presence of adenocarcinoma of the pancreatic head against the background of calculous chronic pancreatitis.

Conclusion: Endosonographic signs of the development of the blastomatous process of the head of the gland against the background of chronic calculous pancreatitis with dilated bile duct. Single enlarged hepatobiliary ligament lymph node.

Subsequent examination revealed focal liver formation, during diagnostic puncture of which cells of clear cell adenocarcinoma were detected. The patient refused the proposed chemotherapy.

Against the background of progressive liver failure, death occurred on June 4, 2003. A post-mortem autopsy revealed low-grade small pancreatic adenocarcinoma with the development of abdominal carcinomatosis, retroperitoneal lymphadenopathy, and liver metastases.

Clinical example 3.

Patient L., 43 years old, was admitted to the Regional Oncology Center in August 2004 with complaints of constant pain in the epigastrium, nausea that is not dependent on food, weakness, weight loss. Sick for about six months. On an ultrasound scan carried out at City Clinical Hospital No. 1, the pancreas with foci of fibrosis is heterogeneous, with a focus of reduced echogenicity in the projection of the head of the gland to 30 × 25 mm. The dimensions of the head are 35 mm, the body is 15 mm, and the tail is 27 mm. Conclusion: more data on the volumetric formation of the pancreatic head. On EGDS - the walls of the descending branch of the duodenum are thickened, rigid, hyperemic, with a biopsy - in the upper bend and the descending branch of the duodenum, signs of chronic inflammation, dysplasia of the glandular epithelium with foci up to 2 tbsp.

Held spiral computed tomography. The liver is not enlarged, of a homogeneous structure, the native density of the parenchyma is about 75 N, the fields of pathological densitometry are not determined. The gall bladder is medium in size, filled with liquid contents, the walls are not thickened. Pancreas: head about 42 mm, density about 38 N with hypodensity fields, body about 30 mm, density about 50 N, tail of similar characteristics, bile duct about 8-9 mm. The walls of the duodenum are thickened to 8–9 mm; the gas content is determined in the lumen. Also, thickening of the walls of the small intestine with liquid wall formations is not excluded. The spleen is of medium size, homogeneous, native density of the parenchyma is about 70 N, the fields of pathological densitometry are not determined. In the retroperitoneal space, additional formations enlarged by l / nodes are not visualized. After intravenous enhancement (omnipack-300, 50 ml), the above organs uniformly accumulate contrast, and pathological densitometry fields are not detected. The head of the pancreas contrast accumulates up to 72 N, the body and tail are similar. Conclusion: CT signs do not exclude the volume formation of the pancreatic head (pseudotumor capitate pancreatitis is not excluded). Signs of duodenitis, enteritis.

On August 17, 2004, endosonography of the pancreatobiliary zone was performed under intravenous anesthesia.

The GF-UM20 echo endoscope was freely carried into the stomach, with technical problems due to the deformation of the LDPC in the upper bend into the descending branch of the duodenum. In the lumen of the stomach and duodenum a moderate amount of bile. The mucosa of the upper bend of the duodenum is hyperemic, edematous, with pitting erosion with deposits of fibrin, villi are hyperplastic. BDS in size is not increased, up to 0.4 cm, pink mucosa. The pancreatobiliary zone was scanned from the standard positions of the echo endoscope.

Bile ducts were examined from the distal and intrapancreatic parts of the common bile duct to hepatic choledoch. The width of the common bile duct is from 3-4 to 6-7 mm. The intrahepatic ducts are not dilated.

In the distal part, the common bile duct narrows funnel-shaped, in the terminal department is not traced (Fig.7).

Vater papilla in size is not increased, up to 8.4 × 4.5 mm, tissue of its usual echogenicity, duodenal muscle layer is traced, thickened, pancreatobiliary fusion is not reliably visualized. The gall bladder was not inspected.

The pancreas is not enlarged in size: in the head region 23-27 mm, in the body up to 16 mm, tail up to 11 mm. In the parenchyma of the hook-shaped process, just below the projection of the pancreatobiliary fusion, an inhomogeneous field of reduced (close to isoechoic) echogenicity is visualized, with fairly clear, irregular contours, with predominantly rounded protrusions of up to 2-3 mm. The horizontal size of the formation is 33.3 mm, the vertical one is 19.3 mm (Fig. 8 — the boundaries of the formation are marked with crosses). Pancreatic pattern in the projection of education is doubtful. The fit of the formation is determined up to 20 mm to the portal vein, without reliable signs of germination in its lumen. The formation is not separated from the wall of the duodenum, wall thickening up to 8-10 mm is determined. The contours of the pancreas in the remaining sections are clear, even, the echostructure is preserved, the parenchyma is moderately heterogeneous, srednenodular, with increased echogenicity septa between segments of lower echogenicity (Fig. 9 - the body of the pancreas).

The Wirsung duct in the field of education is not traced, immediately above it up to 3 mm, in the isthmus up to 2.6 mm, the body and tail up to 1.5 mm. In the lumen of the duct, additional formations are not determined. The wall of the duct is not changed.

Parenchyma of the right and left lobes of the liver of the usual echostructure, isoechoic, pathological changes in the parenchyma within the reach of the echo rays is not determined.

An oval-shaped enlarged isoechoic lymph node is defined with clear, even contours directly next to the hypoechoic formation periodically along the lower edge of the head, up to 9.0 × 6.3 mm in size; in the projection of the hepatobiliary ligament near the neck up to 9.3 × 7.2 mm, another enlarged isoechogenic lymph node up to 10.1 × 7.2 mm in size with clear, even contours is visualized perigastrally along the lesser curvature closer to the posterior wall. Other enlarged lymph nodes in the pancreatobiliary zone, along the splenic vessels, in the area of the celiac trunk are not significantly visualized. The free fluid of the abdominal cavity is determined in a small amount paraduodenally.

According to the proposed method, the differentiation of the volumetric formation of the pancreatic head is carried out. Endosonographic symptoms were scored according to table 1.

1. The determination of the predicted diagnosis is carried out according to the formula for the dependence of the vertical and horizontal sizes of the focus. First, according to the formula Y = 4.1795 + 0.43873 · X, the predicted vertical size of the formation is determined. Y = 4.1795 + 0.43873.33.3 = 18.789209 mm, rounded 18.8 mm.

Then the difference between the real vertical size of the formation and predicted by the presented formula is calculated. 19.3 mm - 18.8 mm = 0.5 mm.

The obtained difference between the real and predicted vertical sizes (or forecast error) was 0.5 mm, which is less than 2 mm, which is more typical for pseudotumor pancreatitis, therefore, we assign 2 points to the value of the coefficient "C" in the formula for the differential diagnosis of pancreatic cancer from chronic pancreatitis.

2. The choledoch contour in the area of contact with the formation is funnel-shaped narrowed, with no signs of growth in the formation of the common bile duct, the value of the coefficient "K" is 1 point.

3. The normal pancreatic pattern in the projection of education is doubtful, so the value of "P" is 2 points.

4. The surrounding focus of the parenchyma gland is moderately heterogeneous, srednenodular, with increased echogenicity of septa between segments of lower echogenicity - the value of the coefficient "O" is 1.

5. Substitute the values in the formula

D = 0.53246 + 0.21578; C-0.048315; K + 0.24554; P + 0.18461; O

D = 0.53246 + 0.215782-0.0483151 + 0.24554-2 + 0.184611 = 1.591395

When comparing the obtained value D = 1.591395 with the numerical values of table 3, it was determined that 1.591395 is more than 1.5, therefore, the presence of pseudotumor pancreatitis of the pancreatic head is more likely.

Conclusion: This echographic picture is more characteristic of pseudotumor pancreatitis of the pancreatic head with inflammatory edema of the duodenal wall. It is impossible to completely exclude the volumetric formation of the hooked process of the pancreatic head, without the development of pancreatic and biliary hypertension, with dubious signs of invasion into the portal vein, with signs of regional lymphadenopathy, with the possible germination of the duodenum wall. Minimal ascites.

Due to the onset and increase of the phenomena of obstructive jaundice and the lack of confidence in the quality of the disease among the attending physicians, the patient was operated on in the Irkutsk Regional Oncology Center in November 2004. Performed pancreatoduodenal resection. Histological examination in a remote macrodrug revealed the effects of severe pseudotumorous chronic pancreatitis.

As of July 2006, the patient is alive.

Table 1 Sign Characteristic Properties point the ratio of the vertical and horizontal dimensions of the outbreak (C) the arithmetic difference of the real and predicted vertical dimensions of the focal formation is more than 3 mm one the arithmetic difference of the real and predicted vertical dimensions of the focal formation is less than 2 mm 2 Assessment of the uniformity of the structure of the pancreatic parenchyma and the presence or absence of focal formation (O) Homogeneous structures with a hearth 0 Inhomogeneous focal structure one Homogeneous structure without outbreak 2 Inhomogeneous structure without a source 3 The contour of the formation in the area of contact with the common bile duct and Wirsung duct (K) Not visualized 0 Lumen is squeezed without growth one Fine tuberous growth 2 Large outgrowths 3 Pancreatic drawing in the lesion (P) No one Doubtful 2 there is 3

table 2 N = 153 Regression Summary for Dependent Variable: group (basa oll 121006.sta) R = 0.887361 RI = 0.787410 Adjusted RI = 0.781664 F (4.148) = 137.04 p <0.0000 Std. Error of estimate: 22666 Beta St. Err. AT St. Err. t (148) p-level Intercpt 0,532463 0.104975 5,07230 0.000001 The contour of the formation in the area of contact with the common bile duct and Wirsung duct (K) -0.099102 0,044222 -0.048315 0.021560 -2.24100 0.026515 Pancreatic Drawing (P) 0,415802 0,055670 0.245539 0,032874 7.46904 0.000000 Assessment of the uniformity of the structure of the pancreatic parenchyma and the presence or absence of focal formation (O) 0.447587 0,054293 0.184609 0,022393 8.24392 0.000000 The ratio of the vertical and horizontal dimensions of the outbreak (C) 0.136853 0,038914 0.215784 0.061357 3,51685 0,000580

Table 3 Nosological form The value of the coefficient D of the differential diagnosis of pancreatic cancer and chronic pancreatitis Pancreas cancer Less than 1.5 Chronic pancreatitis Greater than or equal to 1.5

Claims (1)

A method for the differential diagnosis of pancreatic cancer and chronic pancreatitis, including endosonographic examination of the pancreas and the establishment of signs that reflect the morphological structure of the focal formation, characterized in that the study determines the ratio of the vertical and horizontal size of the lesion (C), the formation contour at the point of contact with choledoch and Wirsung duct (K), the presence of a pancreatic pattern (P) and a criterion that includes an assessment of the presence or tsutstviya hearth and uniformity of pancreatic parenchyma is the formation of focal (G), and Diagnostic coefficient calculated by the formula D:
D = 0.53246 + 0.21578 · C-0.048315 · K + 0.24554 · P + 0.18461 · O,
where C is the numerical value (number of points) for the ratio of the vertical and horizontal size of the lesion, which is determined by the arithmetic difference of the real and predicted vertical dimensions of the focal formation, while the predicted vertical size is calculated by the formula:
Y = 4.1795 + 0.43873 · X,
where Y is the predicted vertical size of the focal formation, mm;
X - real horizontal size, mm,
wherein:
the arithmetic difference between the real and predicted vertical dimensions of the focal formation is greater than or equal to 3 mm - 1 point,
the arithmetic difference between the real and predicted vertical sizes of the focal formation is less than or equal to 2 mm - 2 points;
K is the numerical value (number of points) for the formation contour at the site of contact with the common bile duct and the Wirsung duct:
not visualized - 0 points,
the lumen is squeezed without growth - 1 point,
fine tuberous growth - 2 points,
large outgrowths - 3 points;
P is the numerical value (number of points) for pancreatic drawing in the focus:
no - 1 point
doubtful - 2 points,
there are 3 points;
О - numerical value (number of points) for the criterion, including an assessment of the presence or absence of the focus and heterogeneity of the pancreatic parenchyma outside the focal formation:
homogeneous structure with a focus - 0 points,
heterogeneous structure with a lesion - 1 point,
homogeneous structure without a lesion - 2 points,
heterogeneous structure without a focus - 3 points;
and with a coefficient of D <1.5, pancreatic cancer is diagnosed, and with a coefficient of D≥1.5, chronic pancreatitis is diagnosed.

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