Renal angiomyoadenomatous tumor: morphologic, immunohistochemical, and molecular genetic study of a distinct entity.

We present a series of a distinct tumorous entity named renal angiomyoadenomatous tumor (RAT). Five cases were retrieved from the consultation files of the authors. Histologic and immunohistochemical features were evaluated. Sequencing analysis of coding region of the VHL gene was carried out in all cases. The tumors were composed of admixture of an epithelial clear cell component and prominent leiomyomatous stroma. Epithelial cells formed adenomatous tubular formations endowed with blister-like apical snouts. All tubular/glandular structures were lined by a fine capillary network. The epithelial component was positive for epithelial membrane antigen, CK7, CK20, AE1-AE3, CAM5.2, and vimentin in all cases. In all analyzed samples, no mutation of the VHL gene was found. RAT is a distinct morphologic entity, being different morphologically, immunohistochemically, and genetically from all renal tumors including conventional clear cell carcinoma and mixed epithelial and stromal tumor of kidney.

Myofibroblastic stromal reaction and expression of tenascin-C and laminin in prostate adenocarcinoma.

The aim of this study was to analyse relationship between changes of the stroma and expression of tenascin-C (TN-C) and laminin in prostate carcinoma. Tenascin-C immunostaining was increased, and laminin decreased in carcinomas compared with peritumoral tissue and benign prostate hyperplasia (P<0.05). Statistical analysis confirmed connection between stromal changes and TN-C expression in prostate carcinoma (P<0.05). Gleason pattern 3 carcinomas showed more pronounced stromal reaction and TN-C expression compared with Gleason pattern 4 carcinomas (P<0.05). The main cells in prostate cancer stroma are myofibroblasts that are also responsible for tenascin production. Degradation of laminin was not connected with myofibroblastic stromal changes.