[Testicular cellular fibroma: a clinicopathological observation]

To investigate the clinicopathological characteristics, differential diagnosis and prognosis of testicular cellular fibroma.

We comprehensively analyzed the clinical presentation, histomorphology and immunohistochemistry of a case of testicular cellular fibroma, reviewed the relevant literature, and discussed its pathological features and differential diagnosis.

A 30-year-old man presented with complaint of discomfort and painless enlargement in the right testis. The tumor was found to be a testicular fibroma characterized by a solid, thickly or thinly encapsulated, circumscribed and gray-white mass. Microscopically, fusiform cells were arranged into a storiform and herringbone pattern or fascicles. The tumor exhibited a great deal of cellularity and no nuclear polymorphisms, with a mitotic rate of 0-1/10 HP. Immunohistochemistry showed that the tumor cells were positive for Vimentin, patchily positive for S-100 and SMA, but negative for Desmin, alpha-inhibin, CD34 and CD99. The positive rate of Ki-67 was less than 1%.

Testicular cellular fibroma is a rare testicular sex cord stromal tumor, pathologically resembling its ovarian counterpart. It can be distinguished from other testicular spindle cell tumors by morphology and immunohistochemical staining. For the treatment of testicular cellular fibroma, surgical resection often has a good prognosis.