Fig. 1

Renal cell carcinomas with “clear cells”. (Conventional) Clear cell carcinoma showing typical low-grade areas with nests, acini and cords of clear cells intermixed with a delicate network of capillary vessels (a HE, 100x). Chromophobe carcinoma typically shows sheets of cells separated by incomplete septations. Large eosinophilic cells (oncocytoma-like) commonly coexist with vegetal-like cells (with distinct cytoplasmic membrane). Typical morphology includes wrinkled (“rasinoid”) nuclei and perinuclear halos (b HE, 100x). Multilocular cystic renal neoplasm of low malignant potential shows cystic spaces with delicate septae lined by low-grade clear cells. No expansive growth are observed within septae (c HE, 40x). Clear cell papillary carcinoma typically exhibits tubular and papillary architecture with cuboidal or columnar clear cells and low-grade nuclei uniformly arranged away from the basement membrane (“piano-key-like” pattern) (d HE, 100x). MiT family translocation (Xp11 / TFE3) carcinoma has mixed patterns, but a characteristic feature is the papillary morphology with intermixed clear and eosinophilic cells with high-grade nuclei and the presence of small calcified bodies (e HE, 100x). MiT family translocation (T(6;11) / TFEB) carcinoma’s most distinctive pattern is of a biphasic tumor with large epithelioid cells in the periphery and smaller cell in the center of large nests clustering around basement membrane deposits (f HE, 100x)