顕著な結合組織の増生を伴う牛の腎細胞癌の1例

Abstract

A four-year-old Holstein-Friesian cow, in which rectal palpation demonstrated a large massat the left kidney, was examined pathologically. Macroscopically, the left kidney was markedly enlarged, hard, and pale in color. The lobular structure was preserved. On its cut surface, hard whitish tissue had displaced the renal parenchyma. Numerous hard, whitish masses (1 to 10cm in diameter) were detected between the left renal lymph node and the left iliac lymph node. In histopathological terms, irregular tubules lined with atypical neoplastic epithelial cells were diffused through the left kidney, remarkably proliferated connective tissue, replacing the renal parenchyma. Similar tumor tissues were observed in other hard, whitish masses. The tumor cells stained positive for the anti-uromodulin antibody. Ultrastructural examination revealed the tumorous cells to have microvilli and desmosome structures. On the basis of these findings, the tumor was diagnosed as renal cell carcinoma with marked connective-tissue proliferation.