KR20010099854A - A method and an apparatus for cutting of tissue blocks - Google Patents

Abstract

The present invention relates to a tissue embedding process and apparatus for cutting irregular tissue blocks into slabs having a cross section in the same orientation as any scanning surface used for CT, MRI or PET scanning. Using the embedded device, a tissue block with a regular outer surface that fits within the cutting device is embedded in the alginic acid plastic polymer. The embedding process allows for the reproduction of tissues and organs with irregular faces such as, for example, the brain and kidneys, in a renewable and arbitrary orientation. The device consists of an arrangement of elongated sharp blades in the frame which can be lowered through the operation of the crank. The sharp blade frame is vibrated by a pneumatic vibrator. The alginic acid tissue block is held in position with the vacuum created by the compressed air flow valve.

Description

Method and apparatus for cutting tissue blocks {A METHOD AND AN APPARATUS FOR CUTTING OF TISSUE BLOCKS}

Cleavage of large tissue blocks for pathological examination has typically been performed by hand. The technique includes special pathological knives used to cut tissue organs such as the brain, liver, kidneys and heart. The cleavage technique is rapid and sufficient for daily quantitative testing at a pathology laboratory. However, since manual cutting does not prevent organ deformation, this technique results in tissue cross sections with a wide variety of shapes and thicknesses.

In US Pat. No. 5,148,729, biological tissue slicers are known which can produce thin slices of liver tissue for biochemical, pharmacological or toxicological studies. With this slicer, thin slices of tissue can be peeled from the tissue block one at a time by a reciprocating blade. The slice obtained here is completely inadequate for pathological examination purposes.

US Pat. No. 4,820,504 discloses a multi-sample tissue in which a number of different antigenically reactive tissue specimens are formed into rods, embedded in a vehicle, and then sliced into each cross section including the cross section of the rod. Disclosed is a block and a method for producing a cross section of the tissue block. With this technique, the shape of the final tissue slice is not accurate because it can be deformed during formation and during slicing of the rod. In addition, the cross section can only be used as a check sample of different tissue in a multi- specimen tissue block sliced in cross section.

Current techniques for obtaining tissue sections for pathological examination have high precision and do not prevent deformation of tissue blocks to an acceptable level.

The present invention relates to a method and apparatus for cutting a tissue block for pathological examination. Moreover, the present invention relates to a method and apparatus for producing a tissue convex to be cut in an apparatus using the method.

1 is a perspective view of a device for cutting tissue blocks according to the present invention,

2 shows a cutting frame of the device,

3A and 3B show tissue blocks embedded in a bottom composed of alginic acid and a top mold composed of alginic acid,

4a to 4g show steps in the process of embedding in the embedding apparatus and oriented alginic acid,

5 is a top view of the embedding apparatus of FIGS. 4A-4G.

It is an object of the present invention to obviate the problem of bias when quantitative organ or tissue testing is desired. It is a further object of the present invention to provide a new quantitatively unbiased stereoanalytical technique which requires cleavage of the tissue in cross sections having the same thickness and orientation.

The object is a method of cutting a tissue block into slices in a predetermined orientation, preferably in the same orientation as that of the scanning plane, such as CT, MR or PET, in the tissue block, such as tissues such as internal organs or other internal anatomical tissues. A block is achieved by placing it in a predetermined position and then slicing it into multiple sections at the same time. In a second aspect, the invention provides an apparatus for cutting a tissue block into slices in a predetermined orientation in the tissue block to obtain direct correlation of CT, MR or PET images for pathological examination, wherein the apparatus is adapted to cut the tissue block. And a support surface for receiving, cutting means including a plurality of cutting members, and drive means for moving the cutting means toward the support surface for slicing the tissue block in cross section.

The present invention obviates the problem of deflection when quantitative organ or biopsy is desired. The present invention is ideally suited for new quantitatively unbiased stereoanalytical techniques that require the cutting of tissue blocks in cross sections with the same thickness and orientation. The invention also provides for scanning of the final organ or tissue cross-section corresponding to an imaging medium, such as computerized tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). It is directly correlated with cotton.

In a third and fourth aspect, the present invention includes a method and apparatus for producing a tissue block for cutting in a slicing machine. By this preparation, the organ or tissue is embedded in an alginic acid plastic polymer mold which can be cut in a tissue slicing machine together with the continuously embedded tissue, and finally the present invention also provides a method for Include.

In a first embodiment of the invention of a method and apparatus for cutting a tissue block, the cutting means comprises a plurality of parallel cutting members arranged in the cutting frame. Thereby, the cross section can be easily obtained by simultaneously cutting the tissue block by lowering the frame with the cutting member and passing it through the underlying tissue block.

In a preferred embodiment, the distance between the cutting members can be adjusted. By this, a cross section having a predetermined thickness can be obtained.

The tension of the cutting member can also be preferably adjusted. This eliminates the risk of causing deformation of the tissue during the cutting operation.

In the first embodiment, the cutting member is a sharp blade. The blade allows for sharp and precise cutting without deforming the tissue block during slicing.

In another embodiment, the cutting member may be a wire. This allows a simpler and less expensive solution to be provided as appropriate.

In a preferred embodiment of the present invention, the support surface preferably comprises positioning means for accurately positioning the tissue block embedded in the embedding having a predetermined reference surface. With this configuration, the tissue can be positioned relative to the cutting member such that the final cross section is the same as the scanning face used for scanning.

In a preferred embodiment, the support surface comprises vacuum supply means for holding the tissue block in a predetermined position. This provides a simple and hygienic stable support means.

In a preferred embodiment, a laser pointer is provided for accurately positioning a tissue block on a support surface. The laser can be used for accurate positioning of the tissue block relative to the cutting member by assisting the positioning of the tissue block in the center of the support surface.

The positioning is also provided with a centering concentric marking circle on the support surface and an aiming crosshair on the circle. For example, the centering concentric may be in the form of a concentric recess in the support surface.

In particular, a concentric circular suction ring is provided which can receive a vacuum from the vacuum supply means for holding the tissue block. The ring is particularly useful because a vacuum can be used to place not only the support of the tissue block but also its alignment or centering.

The cutting member is preferably connected with vibration means which vibrate during the slicing action in order to promote the cutting action and to prevent deformation of the tissue during the cutting action.

The vibration means may advantageously comprise a pneumatic vibrator connected to the pneumatic supply means.

The vacuum in the vacuum supply means is preferably generated by the vacuum generating means connected to the pneumatic supply means. This may only reduce the number of control or supply systems required.

In a preferred embodiment, the drive means comprise pillar guide means provided on the support surface and linear actuating means for linearly moving the cutting means towards the support surface along a path defined by the pillar guide means. This allows the cutting frame to move accurately and smoothly linearly up and down relative to the support surface for cutting tissue. By using a die set for the guide means, the reciprocating motion of the cutting frame can be performed substantially loosely, thereby achieving the accuracy of cutting. The linear actuating means comprises a threaded drive spindle parallel to the guiding means and a corresponding thread in the cutting frame.

In a first embodiment, the threaded drive spindle has a handle for manual operation. The drive spindle presents a simple device for performing cutting. However, in other embodiments, the drive spindle may be pneumatically or electrically driven.

In order to prevent deformation during good positioning and cutting of tissue blocks in the device, the invention also relates to a method and an apparatus for manufacturing tissue blocks. Filling a mold having at least one reference plane with an appropriate amount of non-toxic, biologically inert polymer molding material, and placing a tissue block within the polymer molding material in a predetermined position relative to the at least one reference plane when the polymer molding material is in a flexible state. Positioning with a.

By this method, the tissue block is provided with a regular outer surface suitable for the supporting surface of the cutting device due to the mold.

In a preferred embodiment, the tissue block is positioned in the polymeric material in the same orientation as the orientation of the tissue block in vivo. Due to this, the correlation between the scanning image and the cross section can be assured.

The tissue block is embedded in the bottom mold portion and an upper mold is formed in an upper mold formed on top of the lower molding portion with a partially embedded tissue block filled with polymeric molding material, so that the tissue block is completely within the molding. It is built. This provides an effective protection against the other free upper part of the tissue deformed by the cutting member.

In a preferred manufacturing method, the tissue block is fixed to a reference molding of a predetermined dimension, wherein the reference molding is pivoted to a predetermined position in at least one orientation and then molded at least into a bottom molding. Because of this, the orientation of the tissue block can be embedded very accurately with respect to the reference plane.

Polymer materials that are preferably used are low temperature polymers which polymerize upon addition of water, such as alginic acid plastic polymers.

The apparatus and the detailed functionality of the apparatus can be well understood in the dependent claims 33 to 36.

Finally, the present invention also relates to a embedded tissue embedding comprising tissue blocks made by the method and apparatus. Tissue embedding that provides a regular reference surface in the tissue block accurately cuts the block slice for pathological or other purposes. The technique of embedding tissue blocks in alginic acid or similar suitable molding material can be advantageously used before any cutting action, whether the slices are cut one at a time or the slices are cut simultaneously, as in the case of the first feature of the invention.

The invention will be described in more detail later according to the drawings.

1 shows a preferred embodiment of a tissue slicing machine. The tissue slicing machine is located on an aluminum or steel base plate 1 which is preferably placed on a rubber pad or rubber knobs attached to the base plate 1. The base plate 1 by means of column guide means comprising two pillars 3 which allow the top plate 2 to lower and ascend relative to the base plate 1 through the operation of the crank and the spindles 8, 9. Is connected to an aluminum or steel top plate 2. In the center of the top plate 2, the rectangular hole is a space for the attachment of the cutting frame 12. The cutting frame 12 is positionally fixed by a screw or handle on the side of the cutting frame 12. The cutting frame 12 comprises a plurality of cutting elements 14 (see FIG. 2), preferably in the form of thin sharp blades made of hardened steel. The sharp blades 14 are spaced by gap blocks 38, which can be made of metal or plastic. In the preferred embodiment, when the sharp blade 12 is worn and blunt, the cutting frame 12 is replaceable. In other embodiments, as spacing blocks 38 of different thickness, a knife frame 12 may be used that can replace or remove each blade 14. On the side of the top plate 2, a pneumatic or electrically operated vibrator 4 can be located. When the vibrator is actuated, the vibrator vibrates the cutting means comprising the top plate 2 and the knife frame 12 along the longitudinal orientation axis of the sharp blade 14. This reduces friction when the knife 14 passes through the tissue 20 and the alginic acid block 25 (see FIGS. 3A and 3B), thereby facilitating the cutting process. On the side of the top plate 2, a pneumatic valve 7 for compressed air is arranged for operating the embodiment with the pneumatic vibrator 4. The pneumatic vibrator 4 is connected to a pneumatic air valve 7 via an air hose 5. The pneumatic air valve 7 is connected to the compressed air source at the pneumatic inlet 6. In another embodiment, on the other side of the top plate 2 or the base plate 1, a valve 13 for vacuuming with a vacuum exhaust shaft 10 is located. In one embodiment, the vacuum vent shaft 10 is connected to a vacuum pump (not shown). In the second embodiment, a vacuum is provided by a second pneumatic air flow valve (not shown). The vacuum hose 15 connects the vacuum tube 13 to the recess and associated aperture 16 for holding and vacuuming the alginic acid and tissue block 25. At the support surface of the base plate 1, the concentric circles 17 and crosshairs center the alginic acid and tissue block 25. To further center the tissue and alginic acid block 25, a laser pointer 11 is provided on the top plate that faces the central vacuum hole of the vacuum hole 16.

2 shows an embodiment of a cutting frame 12 consisting of knives 14 inclined with respect to the horizontal plane of the base plate 1. This embodiment reduces friction and deformation while cutting the tissue alginic acid block 25. In one embodiment, the knife frame 12 is composed of non-replaceable sharp blades 14 and when the blades are blunt, the entire frame 12 must be replaced. In another embodiment, the knife frame can exchange each blade, and can use spacing blocks 38 of different thickness.

The bearing structure of the tissue slicing machine comprises a column guide base 1 and a top plate 2. The top plate 2 comprises a set of knives 14 positioned in parallel in the frame 12. The knives 14 are mounted in a "knife frame set", and the distance between each knife 14 is spaced by a high tolerance spacing block 38 having the same thickness. The change between the different knife frame sets causes the distance of the knives to change. The frame of the tissue slicing machine is provided with a pneumatic vibrator 4 which vibrates the knife frame set along the longitudinal axis, ie along the cutting edge of the knives. The vibrator 4 of the knife frame 12 reduces friction as the knife frame moves through the alginic acid and the tissue block 25. A knife frame with a vibrator is mounted on a circular lead with a crank 19 which causes the knife frame 12 to move in a vertical plane by rotation. In order to fix the alginic acid and tissue block 25, the base plate 1 of the tissue slicing machine is provided with a suction pad which is operated by opening of the vacuum tube after the placement of the alginic acid tissue block. The concentric ring of the suction pad also serves to center the alginic acid block, just as the laser pointer identifies the center.

3A and 3B, any tissue block 20 or organ is embedded in an alginic acid plastic mold 25. In one embodiment of the invention, the tissue 20 is first embedded in the alginic acid lower mold 22. The embedding is performed by injecting a mixture of alginic acid powder and water into a mold 21, such as a plastic bottle, and then placing the tissue 20 in a flexible alginic-water mixture in the mold 22. Once the alginic acid lower mold 22 is cured, the alginic acid upper mold 23 is cast in a similar manner by placing a second mold 24 such as a second plastic bottle. Then, using anatomical markings, the upper mold 23 is removed for better placement of the alginic acid lower mold 22 in the tissue slicing machine shown in FIG. In a second embodiment, the tissue 20 may be completely cast into alginic acid, followed by CT or MRI scanning of the tissue and the alginic acid block. When placed on a tissue slicing machine in the same way as a CT or MRI scanner, the final tissue cut surface will correspond to the scanning surface. In the embedding process of the third embodiment, the tissue embedded in alginic acid can be cut on conventional tissue cutting machines such as coolers, vibrators, and microtomes.

To embed the tissue, alginic acid plastic polymer from Bayer Dental is used. The alginic acid is a non-toxic low temperature polymer that is polymerized when water is added. Alginic acid powder is stirred in water and then injected into a plastic bottle or other mold 21 of appropriate size for the tissue block. Organ or tissue block 20, such as the pig brain, is still located in a flexible polymer and lies until the alginic acid has cured. The embedding is an important step in the process and orients the tissue 20 in vivo in alginic acid as in vivo. Care must be taken to ensure Such embedding and orientation may be less accurate but can be positioned using anatomical markings on protractor 34-36 and tissue 20 in question. Tissue landfillers should be used for high accuracy. Alternatively, another alginate mold 24 is cast on top of the tissue and the alginic acid bottom mold 22. This is to support the tissue 20 during the cutting step and to avoid deformation of the tissue. Hereinafter, the tissue and alginic acid bottom mold 22 and alginic acid lid 24 will be described.

If scanning is not necessary before pathological extraction of the trachea, another method that can be used is embedding the trachea 20 in alginic acid, and then performing the desired computer scanning of the tissue and the alginic acid block 25 and Then as in the first aspect of the invention. If the tissue and alginic acid block 25 are placed in the cutter in the same way as a CT, MRI or PET scanner, the method will be directed to the orientation of the tissue block 20 because the final digital image scanning plane corresponds to the histological cross section. There is no need.

In the apparatus for cutting the tissue block, the tissue block 25 in which the tissue 20 is embedded is located on the suction pad 16 of the support surface, and the laser and the concentric circle 17 of the base plate 1 of the tissue slicing machine The pointer 11 is centered with respect to the cutting frame 12. After the centering, the alginic acid tissue block 25 is fixed by the action of the vacuum tube 13 and is ready for cutting. The process can be performed with or without the alginic acid cap 24. When the pneumatic valve 7 is opened, the pneumatic vibrator 4 is activated and the cutting frame 12 starts to vibrate. Due to the stable rotational movement, the crank 19 of the columnar reed rotates and the cutting frame 12 descends through the alginic acid and the tissue block 25. The cleavage results in a set of alginic acid and tissue slabs (not shown) having the same thickness and oriented corresponding to the scanning face of a given computer scanning.

4A-4G illustrate a method and apparatus for making a tissue block 20 by embedding the tissue block 20 in an alginic acid plastic polymer. The procedure is performed to orient the tissue 20 where the CT, MRI or PET scanning surface is present.

4A shows a buried device consisting of a central plastic rod 28 with a spherical upper end 28a and two concentric plastic cylinders, an inner cylinder 29 and an outer cylinder 30. The rod 28 is fixed to the plastic base plate 31, on which the cylinders 29, 30 also lie in the retracted position. On top of the outer cylinder 30 four plastic pins 33 with or without threads are positioned at right angles to the long axis of the cylinder 30 (see FIG. 5).

The reference molding die 27 is located on plate means 32 comprising two halves located on the inner cylinder 29 on each side of the rod 28. In this way, the reference molding frame is limited. The mold is filled with a polymer molding material 26 in which the tissue block 20 is located. As shown in FIG. 4B, this means that the tissue block 20 is embedded in the reference mold 26 with the plate means 32 and the frame 27 removed.

4C shows the tissue and alginic acid reference mold 26 located in the embedding device. First, the alginic acid mold 26 is fixed with two plastic pins 33 facing each other 180 degrees. We can define this plane as the X plane. The tilt angle of the tissue and alginic acid reference mold 26 with respect to the horizontal Z plane determined from the desired CT, MRI or PET scanning is determined by protractor 36 (see FIG. 4D) in one embodiment. In the second embodiment, the protractor 36 is equipped with a laser guide 34 which directs the beam 35 in the mold to measure the tilt angle. When the tissue and the alginic acid reference mold 26 are fixed at a desired angle in the X plane, they are fixed in the same way by two plastic pins 33 positioned perpendicular to the Y plane.

4E shows the mold of the second alginic acid bottom mold 22. The shape of the bottom mold 22 is adapted to fit into the tissue slicing machine of FIG. 1. First, as the outer cylinder 30 is raised, the second base plate 37 slides into the corresponding horizontal opening in the outer plastic cylinder 30 and the outer cylinder 30 forms the sides of the molding die. 2 Alginate bottom mold 22 is cast.

Referring to FIG. 4F, the upper mold 21 is disposed on the outer cylinder 30, and then the alginate upper mold 24 is cast on the bottom mold 22 and the upper part of the tissue block 20.

4G shows that the alginate molding 25, ie, the reference mold 26, the bottom mold 22 and the upper mold 24, after the outer cylinder 30 has been slid down toward the base plate 31, has been removed. A buried tissue block 20 is shown.

5 shows a top view of the outer cylinder 30, the inner cylinder 29, the central rod 28 and the plastic pin 33 for pivoting the reference mold 26 of the tissue block. .

The embedding device allows for accurate three-dimensional orientation of tissue reference molding 26 for CT, MRI or PET scans. Once the correct orientation of the tissue reference molding 26 is made, a second molding is performed to create a second alginic acid bottom 22 having an outer surface that fits into the tissue slicing machine. If desired, the final alginic acid cap 24 may be cast on top of the tissue 20 and the alginic acid bottom 22 to avoid deformation of the tissue during the cutting process. The buried device includes a circular rod 29 of transparent plastic such as plexi-glass or similar material, two outer concentric plastic cylinders 29 and 30, a fixing pin 33 and a semi-circular plastic plate. 32 and an insertable base plate 37, preferably made of plastic material.

Claims (39)

A method of cutting a tissue block into slices in a tissue block, preferably in a predetermined orientation equal to the orientation of the scanning surface such as CT, MR or PET scanning, A tissue block, such as an internal organ or other internal anatomical tissue, is placed in a predetermined position and then sliced into multiple sections simultaneously. A method according to claim 1, wherein the cutting is performed simultaneously by a plurality of cutting members oriented in parallel. The method of claim 1 or 2, wherein prior to positioning, the tissue block is fixed in a predetermined orientation equal to the orientation of the tissue block in vivo. The tissue block of claim 1, wherein the tissue block is positioned on a support surface for cutting and maintained in a predetermined position by applying a vacuum to one or more suction pads on the support surface just below the tissue block. How to feature. The method of claim 1, wherein the cutting member is mounted on a frame for engaging and cutting the tissue block disposed directly below the cutting member. The method of claim 5 wherein the cutting member is vibrated during the cutting operation. The method of claim 1, wherein centering the tissue block on the support surface is performed prior to the cutting operation. An apparatus for cutting a tissue block into slices in a predetermined orientation in the tissue block to obtain direct correlation of CT, MR or PET images for pathological examination, Support surfaces for receiving tissue blocks, Cutting means including a plurality of cutting members, and And drive means for moving the cutting means towards the support surface for slicing the tissue block in cross section. 9. An apparatus according to claim 8, wherein the cutting means comprises a plurality of parallel cutting members arranged in the cutting frame. 10. An apparatus according to claim 8 or 9, wherein the distance between the cutting members can be adjusted. The device according to any one of claims 8 to 10, wherein the tension of the cutting member can be adjusted. 12. The device according to any one of claims 8 to 11, wherein the cutting member is a sharp blade. The device according to claim 8, wherein the cutting member is a wire. Apparatus according to any one of the preceding claims, characterized in that the support surface comprises positioning means for accurately positioning the tissue block embedded in a landfill having a predetermined reference surface. The apparatus according to any one of the preceding claims, wherein the support surface comprises vacuum supply means for holding the tissue block in a predetermined position. 16. The device of claim 14 or 15, wherein a laser pointer is provided for accurately positioning the tissue block on the support surface. 17. An apparatus according to claim 14, wherein a centering concentric marking circle is provided on the support surface and an aiming crosshair is provided on the circle. 17. An apparatus as claimed in claim 14 wherein concentric recesses are provided in the support surface. 19. The device according to any one of claims 14 to 18, wherein a concentric circular suction ring is provided that can receive a vacuum from the vacuum supply means to hold the tissue block. Apparatus according to any one of the preceding claims, wherein the cutting member is connected to vibrating means that vibrate during the slicing action. 21. An apparatus according to claim 20, wherein said vibrating means comprises a pneumatic vibrator connected to a pneumatic feeding means. 20. An apparatus according to any of claims 21 and 14 to 19, wherein the vacuum in the vacuum supply means is generated by a vacuum generating means connected to the pneumatic supply means. 23. The drive means according to claim 8 to 22, wherein the drive means comprises pillar guide means provided on the support surface and linear actuating means for linearly moving the cutting means toward the support surface along a path defined by the pillar guide means. Device characterized in that. 24. The apparatus according to claim 23, wherein the linear actuating means comprises a threaded drive spindle parallel to the actuation guide means and a corresponding thread in the cutting frame. 25. The device of claim 24, wherein the threaded drive spindle has a handle for manual operation. The apparatus of claim 23, wherein the drive spindle is pneumatically or electrically driven. A tissue block, such as an organ, is produced from a tissue retentate to obtain a tissue block having a reference position for use in the method according to claims 1 to 7 and the device according to any one of claims 8 to 26. In the method for Filling a mold having at least one reference plane with an appropriate amount of non-toxic, biologically inert polymer molding material, and placing a tissue block within the polymer molding material in a predetermined position relative to the at least one reference plane when the polymer molding material is in a flexible state. Positioning with a. The method of claim 27, wherein the tissue block is positioned in the polymeric material in the same orientation as the orientation of the tissue block in vivo. 29. The upper mold according to claim 27 or 28, wherein the tissue block is embedded in the bottom mold portion and the upper mold is placed in an upper molding mold disposed on top of the lower molding portion filled with a polymer molding material and having a partially embedded tissue block. And wherein said tissue block is fully embedded in the molding. 30. The tissue block according to any one of claims 27 to 29, wherein the tissue block is secured to a reference molding of a predetermined dimension, wherein the reference molding is pivoted to a predetermined position in at least one orientation and then molded at least into a bottom molding. How to feature. 31. The method of any of claims 27-30, wherein the polymeric material is a low temperature polymer that polymerizes when water is added, such as an alginic plastic polymer. 27. An apparatus for producing a tissue embedding according to the method according to any one of claims 27 to 30 for use in an apparatus according to any one of claims 8 to 26. First molding means comprising a first molding means for forming a reference molding mold for embedding the tissue block in the molding, the first molding means comprising a tubular side portion and a first bottom plate means for providing a bottom surface to the reference molding mold; Positioning means comprising at least one set of pivoting means for pivoting a reference mold, and And second molding means forming a bottom molding mold, the second molding means having a retractable tubular sidewall and a second plate means for providing a bottom surface to the bottom molding mold. 33. The device of claim 32, wherein a third molding means is provided for forming the upper molding mold, wherein the third molding means comprises a tubular sidewall frame having a generally same cross section as the tubular sidewall of the second molding means. Device. 34. An apparatus according to claim 32 or 33, wherein a centrally retractable piston is provided, the piston having a hemispherical end that enters and forms into the reference molding frame when extended. 35. The pivoting means according to any one of claims 32 to 34, wherein the pivoting means comprises two pins arranged in alignment with the outer peripheral area of the second molding means facing each other, the pins having a desired mold. And radially insertable into the reference mold to form a pivot axis for pivoting into position. 36. An apparatus according to claim 35, wherein two sets of pivoting means are provided to form two pivot axes which are preferably orthogonal to each other. A tissue for providing a predetermined reference plane for determining the exact position of the tissue block in the device according to any one of claims 8 to 26 for carrying out the method according to any one of claims 1 to 7. In the landfill, Tissue blocks, such as internal organs or other internal anatomical tissue, are at least placed in a mold with a predetermined reference surface, preferably a bottom surface, for accurate positioning in the device for cutting the tissue block for pathological examination purposes. Tissue embedded, characterized in that partly fixed. 38. The tissue buried material according to claim 37, wherein the tissue block is provided with a bottom mold part and an upper mold part, and the tissue block is embedded inside these mold parts. 39. The tissue embedding of claim 37 or 38, wherein the mold portion is made of a non-toxic plastic polymeric material, in particular an alginic acid plastic polymer.