Gross Dissection Protocol for Radical Cystectomy(GDPRC) Specimens

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Gross Dissection Protocol for Radical Cystectomy(GDPRC) specimens

Unopened surgical samplesare fixed in 10% formalinfor a minimum of 3 days. To increase the inflow of formalin, a Foley catheteris used. Cautious fillingis applied in order to avoid expansion. The gross dissection procedure for cystectomy specimens for both male and female urinary bladders is outlined schematically in Fig. 1 in the article. The origin of each histology sample is recorded in the final report.

The first step is 3Dmeasurement of the dimensions and recording of the weight. This is followed by a description of each organ and measurement of the lengths of the ureteral stumps. In cases when the clinically preparedureters are not attached to the specimen, attempts are made at identification before inking of the entireresectionsurface of the whole specimen.

Processing is started by inking the resection surfaceswith black ink on the right side and alcian blue on the left. After drying of the ink and removal of the excess ink with a coarse paper towel, an anterior orientational incisionis made. Under the guidance of a metal probe, scissors are used to make an openingfrom the urethral orifice to the bladder dome (Fig. 2). This serves three purposes:

1. It allowsviewing of thebladder lumen.

2.It allows localization of the base of the male bladder and facilitates determination of the bladder base from which the basalslice,i.e. thebladder-prostate basal block (BB),is formed.

3. The irregular transmural cut surface adequately indicates the anterior direction in microscopic sections (Fig. 4a and 4b).

After the orientational incision,the male and female urinary bladders are processed in different manners:

Gross dissectionsteps of the male urinary bladder

1. Aurethral resection lineis made producing a 3–4-mm-thick cross-section. If microscopic examination verifies the presence of neoplasia in aurethral localization or in the apical part of the prostate, the tissue is melted out from the block, and sagittal sections are made, rotated through 90º and re-embedded.

2. The entire prostate is embedded in the form of cross-sections. However, in order to retain all the surgical markings in the sections, the samples are formed in a wedge shape.Due to the anteflexion of the axes of the prostate and the bladder, the transverse resection level of the urethra and the BB are not parallel, the subsequent cutting levels forming a posterior open angle.The maximum height of the base of the triangular posterior surface is5 mm.In the presence of prostate tumour,its infero-superior extension is estimated as half of the maximum thickness of the triangular block.

3. The thickness of the BBallows 12radially cut sections,forming blocks that fit into a standard cassette (Fig. 4c).The thickness of the BBis assessed by palpation through the orientational incision.

4. The 12 radial sections of the BBare made by completing the orientational incision in a backward direction. This isfollowed by halving the right and left parts and trisecting the resulting quarters. All levels start from the urethra and reach the circumferential resection margins. Cutting directionsare predetermined: they are made from right to left, as if the BB were virtually spread out and the anatomical situation of a person facing the pathologist were reconstructed. The result is a series of wedge-shaped sections, which are placed in a standard cassette with the informative section facing downwards, taking into account the direction of circling from right to left. If the sectionsare longer than the standard cassette, the remaining partis placed into another standard cassette with maintenance ofthe orientation and marked at the dissection. Tissue parts thicker than the height of the standard cassette are cut off.

5. Creation of bladder cross-sections from the area above the BB.The bladder lumen is not inflated. Formalin penetration transmurally or through the urethra produced an appropriate consistency afterthe 3 days of fixation. The specimen can be accurately cut up using a sharp brain knife. It is borne in mind at all times that the success of fine sectioning depends on the continuous movement of the knife. With this method, cross-sections with a thickness of 7 mm can be sliced. Commercially available macro cassettes(Thermo Scientific E10SM/WHITE) are used in our Institute. These measure 65 mm x 49 mm x 15 mm. One or two macro cassettesare used for each cross-section. If these prove to be too small, parts of the perivesical adipose tissue distantfrom the tumour are cut off.

6.Processing of the bladder dome. The anterior presacral adipose tissue (also containing remnants of the urachus and the bilateral umbilical arteries)is removed through a transverse slice. Accordingly, an approximately 20-mm-thick dome is left behind.This sample is carefully examined, and those parts which look abnormal are embedded in standard cassettes. The dome itself is processed into large blocks. Sagittal slices are made, each 5 mm thick.In cases when the lateral side of the dome is involved by tumour, the sagittal section is also processed by applying further parallel frontal cuts(Fig.1on 5a, and Fig. 5 green arrowheads).

7. The roots of the seminal vesicles connected to the prostate are embedded in large blocks. The remaining glands are embedded as cross-sections.

Gross dissectionof the female urinary bladder

1.The uterus, together with its bilateral appendages and the antero-superior area of the vaginal wall,isseparated from the bladder

2.The first cross-section containing the urethral resection levelis cut in such a way that the clinically prepared resection margin is brought to the level of microscopic examination (in the course of embedding, on the bottom of the macro block). In the event of microscopic confirmation of involvement, supplementary re-embedding and examination in parallel sagittal sections may be formed.(The base of the female urinary bladder is so thin that radial processing and embedding are unsuccessful.)

3.The bladderis embedded in the form of cross-sections, using one or two macro blocks. When the axis of the bladder showssignificant anteflexion, cross-sections are cut at a posteriorly open angle rather than in parallelslices.

4.The processing of the bladder domeis identical to the cutting-up steps for the male bladder.

5.The uterine cervixand the vaginal stump are embedded in sagittal parallel sections following separation from the cervix.

6.The entire area of the uterine columnadjacent to the urinary bladder below the peritoneal pouchis embedded as cross-sections.

7.The uterine corpus and its bilateral appendages are prepared for examination according to the internationally accepted procedural protocol.

Reporting the findings

Evaluation of the histology findings

The evaluation of the microscopic slideinvolves the following steps.Starting from the orientational incision, the mucosal surface is examined. The dimensions of the dysplasia/in situ carcinoma and its relationship with the infiltrative tumour are determined and expressed as percentages (see Standardized Reporting Formbelow). Next, the circumference of the tumour infiltrating the wall is determined and marked. Attention is paid to the involvement of vascular and neural structures. The entire section is then reviewed by proceeding in the meander line customary in cytology. It is at this time that tumour foci independent of the main tumour mass,the perivesical lymph nodes and ureter cross-sections are soughtin the cutting level.The growth pattern of the tumour is evaluated. The 2D dimensions of the tumour are determined. Finally, the distance and the width of the closest circumferential resection margin are measured and its location is marked.

Standardized Reporting Form

To facilitate the reviewing of the large number of histological sections, a Standardized Reporting Form(Fig. 6) is used. The data necessary for the pathological reporting are recorded for each section. The form consists of a graphical part on the left-hand site for the indication of locations, and a table on the right-hand site for the recording of numerical data. Each line in the numerical part is associated with a pair of joined lines in the graphical part. Each of these groups of three lines corresponds to one of the histological sections, starting at the top with the bladder dome and proceeding downwards as shown by the sections in Fig.1, and finishing with the lobes of the prostate. Overall, therefore, the graphical part schematically reflects the sections of the stretched-out urinary bladder.

The upper lines of the line-pairs in the graphical part are divided into blocks by the pathologist, each block indicating the presence or not of an epithelial lesion, and also its approximate size. Simple abbreviations are used, e.g. N= no aberration; D/IS=dysplasia/in situ carcinoma; INV= invasive tumour; DE = denuded epithelium. The lower lines of the pairs serve for the recording of the involvement of the subepithelial layers of the bladder wall. Taking into account the localization and the approximate size, the most advanced stage is recorded, using the TNM system. Subcategories pT1a and pT1b are differentiated. The circles next to the rectangles represent the uretercross-sections. The same symbols areapplied for the phenomena in the cross-sections as those used for the bladder. The representation of the bladder dome is divided into four parts,which can be further subdivided according to the number of sagittal sections. The BB is divided into 12 parts, corresponding to the number of samplestaken. The pars prostatica urethrea is shown between rectangles representing the two lobes of the prostate. Alphabetical symbols can be written in the space between the rectangles. The neighbouring rectangles serve for the marking of the depth of urethral tumour infiltration. Prostate tumours can also be recorded in the appropriate lobe. Involvement of the resection margin can be indicated by thickening the sides of the rectangles.

Numerical dataare also recorded in thetable. The first three columns on the right provide data on the epithelium: the estimated percentages of the normal (N) and invaded (INV) areas and that involved by dysplasia/in situ carcinoma (D/IS). When the total of these is less than 100%, the difference corresponds to the denudedarea. The next two columns relate to the tumour: the column “Tumour type” serves for a description of the growth pattern. The depth and width of the tumour reflect the size of the infiltrated area in millimetres. The capillary(C),vein(V) and perineural (PN) columns are for data on the tumour spread.The size of the largest infiltrated vessel and estimated number of involved structures are recorded.The last column is for the minimum distance of the circumferential resection margin in millimetres.

The table is completed in the sequence of the cutting-up upprocedure, startingat the urethral resection margin, and proceeding from the bottom upwards. When there are fewer cross-sections than available rectangles, those not needed are simply left empty. When there are more, additional printed forms are used. Figure6 illustrates a completed form.

In compliance with the practice accepted in Hungary, the histological findings are also presented in a written report.

The GDPRCcan be implemented in a flexible manner. The most frequent modification is a reflection of the cutting surface if this indicates any suspicious area. Clinical opening of thespecimen also requires modification of the cutting-upprocedure.In such cases,efforts are made to follow the protocol as completely as possible. Incasesinvolving adilated bladder, more macro blocksare used.

The roots of the seminal vesicles are presented in the prostate sections. The remainingglands are embedded in the form of cross-sections. Lymph node samples are embedded complete; large lymph nodes(>4 mm) are halved.