Cassette for pathological tissue examination

Abstract: This invention provides a cassette for pathological tissue examination which consists of a container proper (1) and a lid (2) thereof engageable therewith and detachable therefrom both made of a chemical-resistant synthetic resin, wherein the aforementioned container proper has a plurality of sample chambers (4) independent and separated from one another when the container proper is closed, a large number of small through-­ holes (5) are made in the bottom of the container proper having the aforementioned sample chambers formed therein and the lid, and either or both of the container proper and the lid is/are provided with a recording space (13) in which the name, serial No. et cetera of the examinee can be written or otherwise recorded. The cassette of the invention features easy taking-in and taking-out of samples and treatment thereof with alcohol et cetera, ensures prevention of primitive errors such as mistaking the examinees or the places the particular samples were taken from, excellent in workability and contributes to improvement in efficiency as well as reliability of such examination.

Description: The present invention relates to a cassette for pathological tissue examination of the type as indicated in the preamble portion of claim 1. A biological tissue cassette of this type is known from US-A-4,421,246. Said conventional tissue cassette is for the treatment of only one sample. From US-A-3,768,914, there is known an electron microscopy tissue grid staining and storing rack which is for simultaneously treating a plurality of samples in a plurality of chambers, wherein a marking space is provided near each sample chamber. The present invention relates to a cassette for pathological tissue examination and, more particularly, to such cassette which can improve the workability or efficiency of making preparations for microscopy including taking-in of a medical sample such as of a living body tissue and chemical treatment thereof at the same time helping improve the efficiency and reliability of such examination. Today, in the diagnosis of cancer et cetera the method of histologically examining tissue samples taken from a living body, the so-called biopsy is widely used. In such a biopsy, for example, a sample of approximately 0.5 - 5 mm of the object living body tissue is taken, rinsed with water, treated with xylene after dehydration with alcohol and then embedded in paraffin, and it is sliced to make preparations for microscopic examination. Hitherto, as container for such a tissue sample, a cloth bag made of a chemical-resistant fiber, some 4.5 cm long and 6.5 cm wide and approximately 0.2 mm in mesh size was used, a tissue sample was taken in and the mouth of the bag was closed before the aforementioned treatment was proceeded with. This method is, however, extremely poor in workability and, especially when a fraction of the sample is in a corner or the bottom of the bag, it is by no means easy to take it out using a pair of pincers. Further, while in biopsy it is usually the case that, even if the object organ is one, several samples of living body tissue are taken from different parts of the organ, the method described above using a mesh bag lacks marking means, hence when several samples are taken into a bag, they are indistinguishable, and the method being used in practice nowadays is to take each sample into one bag together with a card or the like with the name et cetera of the examinee written thereon, being thus dreadfully inefficient. Also, in such a method, if the aforementioned card or the like should come out of the bag, the examinee is no longer identifiable and other necessary data, if any, are lost, this badly interfering with the reliability of the examination, and, worse, a separate container having through-holes therein, the so-called cassette, is required when the taken living body tissue is embedded in paraffin for making preparations for microscopy. There are also many other problems such as the possibility of the taken sample being deformed when the bag is subjected to even a small force. It is the object of the present invention to provide a cassette for the simultaneous treatment of a plurality of samples and to provide a cassette block of said plurality of samples while avoiding errors in the identification of the samples and making said cassette block rigid and stable enough to allow a cassette block to be sliced by the use of a microtome. The above object is achieved by the subject matter of claim 1. Preferred embodiments and further improvements of the inventive cassette are defined in the depending subclaims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an embodiment of the present invention. FIG. 2 is a plan view thereof with the lid opened. FIG. 3 is a sectional view taken along the line B - B in FIG. 2. FIG. 4 is a bottom view corresponding to FIG. 2. FIG. 5 is a plan view showing another embodiment of the present invention. FIG. 6 is a plan view showing still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cassette for pathological tissue examination which consists of a container proper and a lid thereof engageable therewith and detachable therefrom both made of a chemical-resistant synthetic resin, wherein the aforementioned container proper has a plurality of sample chambers independent and separated from one another when the container proper is closed, a large number of small through-holes are made in the bottom of the container proper having the aforementioned sample chambers formed therein and the lid, and either or both of the container proper and the lid is/are provided with a recording space in which the name, serial No. et cetera of the examinee can be written or otherwise recorded. Of the drawings showing embodiments of the present invention, FIG. 1 is a schematic view of the cassette of the invention, FIG. 2 is a plan view thereof with its lid opened, FIG. 3 is a sectional view taken along the line B - B in FIG. 2 and FIG. 4 is a bottom view corresponding to FIG. 2. Referring to these figures, the cassette of the present invention consists of a container proper (1) and a lid (2) and these are connected by a hinge (3). The aforementioned container proper (1) has formed therein a plurality (5 in the figure) of sample chambers (4) and in the bottom of the sample chambers (4) are made a large number of small through-holes (5). Near both ends of the container proper (1) there are provided sunken parts (6) and (7) and on the side opposing the lid of the container proper (1) is provided a recording space (13) for writing or otherwise recording the name, serial No. et cetera of the examinee. Meanwhile, on the back of the aforementioned lid (2) there are provided the same number and size of projected rims (8) to match the sample chambers (4) of the aforementioned container proper (in the opposing positions), and there are made a large number of small through-holes (9) inside these projected rims (8). Near both ends of the lid (2) there are provided projections (10) and (11). It is so designed that the vertical length (L 1 ) of the lid (2) is slightly larger than the length of the container proper (L 2 ) so that, when the container is closed, the lid (2) projects by a proper dimension beyond the ends of the container proper (1) so that holders (12) for opening the lid (2) are provided, and that the lid's horizontal length (W 1 ) is smaller than the length (W 2 ) of the container proper so that the aforementioned recording space (13) is not covered. The container proper (1) and the lid (2) as described above are mated when the hinge (3) is bent inward so that the projections (10) and (11) of the lid (2) fit in the sunken parts (6) and (7) of the container proper (1) and the projected rims (8) of the lid (2) fit in the sample chambers (4) of the container proper (1) respectively for 5 independent and tightly sealed chambers to be formed thereby. To open the container, the holder (12) may be held with fingers and the lid (2) is lifted to break the aforementioned engagement. According to the present invention, the container proper (1) and the lid (2) are both made of a chemical-resistant synthetic resin. As chemical-resistant synthetic resin, there may be included, for example, polyacetal resin, polyamide resin, polycarbonate resin, polyester resin and fluorocarbon resin. As to the number of the sample chambers (4), there is no particular limitation, but 3 - 9 is considered proper when the preferred overall size of the cassette of the present invention is approximately 20 - 30 mm in length, 30 - 40 mm in width and 5 - 8 mm in height with the ease in handling taken into consideration. If this number is less than 3, the sample-holding capacity is supposed to be insufficient, while, if it is more than 9, the size of each sample chamber is bound to be too small, this possibly interfering with manipulation by the use of pincers. There is no particular limitation with regard to the shape of the sample chamber, either, but it may preferably be cylindrical, for this precludes the possibility of sample in a corner being inaccessible and also facilitate manipulation with pincers. The size of small through-holes (5) and (9) may preferably be in a range of 0.2 - 0.7 mm or so. If it is too small, the permeability to alcohol, xylene or liquid paraffin described below becomes insufficient, while if it is too large, there is a risk of tiny samples dropping through such through-holes. Also, it is preferred to have the small through-holes (5) tapered to be narrower toward the chamber interior, and the small through-holes (9) tapered to be broader toward the chamber interior. This not only prevents the small through-holes being clogged with the sample but also improves their permeability to alcohol, paraffin or the like. In the aforementioned figure there are provided on the back of the container proper (1) paraffin engaging and reinforcing parts (14) are provided. This construction not only increasing the engaging force between the underside of the container proper and paraffin but also is effective for reinforcing the container proper (1), hence the wall thickness of the container proper can be made smaller, the permeability to alcohol, xylene and paraffin can be improved and, as will be described later, reinforcing effect is exhibited when a cassette block is sliced by the use of a microtome. FIG. 5 is a plan view showing another embodiment of the present invention, and in this embodiment the container proper (1) is separated from the lid (2). FIG. 6 shows a still another embodiment of the present invention, and here a marking part (15) is provided near each sample chamber (4) of the container proper (1). This marking part is pear skin-finished to allow writing with a ball-point pen or the like and is used for recording a number or signal for identifying where the particular sample was taken from or the like. An example is given below according to the cassette shown by FIG. 1 to 4 to show how it is used. The sample is first taken into the sample chamber (4) of the container proper (1), the container is closed with the lid (2) and the sample is rinsed with water by means of the small through-holes (9) and (5) and then alcohol is passed through these holes for dehydrating the sample (part of the fat it contains is also removed at this stage). Then xylene is passed through for imparting to the sample affinity for liquid paraffin. Now, liquid paraffin is filled in a stainless steel tray, the desired sample is taken out of the sample chamber and properly placed on the liquid paraffin in the tray, the cassette is placed on the supporting means provided on the side of the tray, and liquid paraffin is poured over the sample placed on the aforementioned liquid paraffin until the bottom of the cassette comes into contact with the liquid paraffin. After solidification of the liquid paraffin the tray is removed, and there results the so-called cassette block, which consists of the sample embedded in paraffin and the bottom of the cassette of the present invention, these forming a single body. The paraffin-embedded sample portion of this cassette block is then sliced by the use of a microtome to make preparations for microscopy. The cassette for pathological tissue examination of the present invention has a good many advantages as enumerated below, being thus highly useful. (1) A plurality of samples can be taken into plural, independent sample chambers, hence it is possible to treat simultaneously samples taken from a plurality of patients or samples taken from a single patient. (2) A plurality of samples can be handled en bloc in a single treatment with alcohol or xylene. (3) The cassette of the present invention can be used as it is also for making the cassette block using paraffin, being thus highly useful. (4) By provision of the paraffin engaging and reinforcing means, secure engaging of the paraffin block with the bottom of the cassette is attainable and, moreover, a high reinforcing effect is attainable so that the wall thickness of the container proper can be reduced for smoother passage or permeation of alcohol or paraffin, and the reinforcing effect is also exhibited when slicing is done using the microtome. (5) The lid and/or the container proper are/is provided with the recording part in which the necessary data can be written or otherwise recorded, hence primitive yet grave errors of mistaking the examinees and the like can be precluded. Also, by writing the number, signal and the like for identifying where each sample was taken from troubles such as mistaking the samples taken or mistaking the place a given sample was taken from can be avoided, the cassertte of the invention thus contributing to improvement of the reliability of examination. (6) Made of a synthetic resin, the cassette is safe from deformation even if it is subjected to a pretty large force. (7) Compared with a conventional bag made of "mesh" cloth, taking-in and taking-out of samples is easier with the cassette of the present invention, this also featuring an improved permeability to alcohol or paraffin and better workability.

Claims: A cassette for pathological tissue examination consisting of a container proper (1) and a lid (2) thereof engageable therewith and detachable therefrom both made of a chemical-resistant synthetic resin, wherein a large number of small through-holes (5,9) are made in the bottom of said container proper (1) and said lid (2) and either or both of said container proper (1) and said lid (2) is/are provided with a recording space (13) in which the name, serial number, et cetera, of the examinee can be written or otherwise recorded; wherein at least one projection (10,11) is provided on said lid (2) and at least one corresponding sunken part (6,7) is provided in the container proper (1) such, when said container proper is closed, said projection of the lid fits in the sunken part of the container proper; characterized in that (a) said container proper (1) has a plurality of cylindrical sample chambers (4) presenting no corners, independent and separated from one another when said container proper (1) is closed, wherein the large number of small through-holes (5,9) are made in the sample chambers, in the bottom of said container proper (1) and said lid (2); (b) a paraffin engaging and reinforcing part (14) is protrudingly provided on the side and bottom of said container proper (1); and (c) marking space (15) is provided near each sample chamber (4). A cassette in accordance with claim 1 wherein the number of said sample chambers (4) is 3 to 9. A cassette in accordance with claim 1 wherein the diameter of said small through-holes (5,9) is 0.2 to 0.7 mm.

Inventors: MURAZUMI TAKUYA, YAMAMOTO TADASHI, MURAZUMI, TAKUYA, YAMAMOTO, TADASHI
Applicants: MURAZUMI IND CO LTD, MURAZUMI INDUSTRIAL CO., LTD.
Application year: 1988
Main classification: G01N1
IPC codes: G01N1, G01N33