The efficiency of immunohistochemical techniques for the diagnosis of vitality of wounds decreases for lesions occurring fairly close to death. We analyzed the expression of fibronectin (FN) and tenascin (TN) in wounds inflicted in abdominal skin of 12 adult rats. An incised injury was made at 5, 10 or 15 min before death and another at 5 min after sacrifice, and collected after 45 min. Formalin-fixed paraffin-embedded sections from a total of 36 samples (mean 1.5 per wound) were immunostained following the streptABC technique. Microscopic examination revealed a reticular pattern staining in 18 out of 20 vital samples for FN, 16 out of 20 for TN, 2 out of 16 postmortem samples for FN and 3 out of 16 for TN. Intracellular staining of muscle fibres was observed in 7 out of 20 vital and 5 out of 16 postmortem samples. FN and TN were detected in most of the vital injuries but they are not completely specific. Postmortem staining occurred in a few cases probably related to a passive extravasation of these molecules from damaged blood vessels. Reactivity of muscle fibres occurs both in vital and postmortem lesions, and is not useful in the diagnosis of vitality.

A case of mucinous urothelial-type adenocarcinoma of the prostate in a 68-year-old man is reported. This is a rare neoplasm which probably originates from the proximal prostatic ducts or the prostatic urethra. This tumor does not express prostate-specific antigen, in contrast to the more common mucinous adenocarcinoma of the prostate, and may be misdiagnosed as a secondary, mainly colorectal, tumor. Clinical examinations and immunohistochemistry may help in the differential diagnosis. Owing to local recurrences two transurethral resections of the prostate were performed in our patient during 3 years of follow-up. He died from this tumor 40 months after the first biopsy.

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CDX2 is a transcription factor expressed by intestinal epithelium. It is considered as a sensitive marker for a colorectal or-less frequently-gastric origin of adenocarcinomas. The pattern of coordinated expression of cytokeratin (CK) 7 and CK20 is also useful for the diagnosis of the origin of metastatic adenocarcinomas. Expression of CDX2, CK7 and CK20 was investigated in 14 cases of sinonasal intestinal-type adenocarcinoma (SIA), a particular tumor with an enteric-cell-type appearance. Formalin-fixed, paraffin embedded tissue sections were immunostained with monoclonal antibodies using the biotin-labeled streptavidin technique. All of the cases expressed CDX2, being stained 50 to 100% of the tumor cells (mean: 87.2%). CK7 positivity was detected in 8 cases (57.1%), with the staining of 10 to 100% of cells (mean: 65.6%), and CK20 was found in all the tumors (10 to 100% of cells; mean: 78.8%). The histologic resemblance between SIA and colorectal adenocarcinoma is reinforced by the expression of CDX2 and CK20, which are virtually constant in both neoplasms. CDX2 seems to be a marker for cellular phenotype better than an indicator of the origin of adenocarcinomas. CK7 is expressed in SIA less frequently than in colonic adenocarcinoma, but with a rate similar to the subset of rectal tumors, making the differential diagnosis between the two neoplasms difficult.