Cystic Renal Oncocytoma: A Case Report with Review of the Literature

Susanna Syriac, MD, Wilfrido Mojica, MD, Frank Chen, MD, PhD, Shaozeng Zhang, MD, PhD


Renal oncocytomas are benign, predominantly asymptomatic tumors that are usually found incidentally.  These tumors are typically solid, well-circumscribed, homogenous tan-brown lesions, often with a central fibrous scar. Histologically, the tumor cells are arranged in solid compact nests, acini and tubules of variable size, all within a hypocellular hyalinized stroma. In the literature, there are only five cases of cystic renal oncocytoma reported. Herein we present a case of cystic renal oncocytoma with the unusual gross appearance of multiloculation. It was found incidentally on imaging studies in the upper pole of the right kidney.  Grossly, it was a well-circumscribed 1.5 cm mass with a multiloculated cystic cut surface. Microscopically, the oncocytic cells were arranged along the septae that divided the mass into multiloculated cysts. Immunohistochemical staining of the tumor showed expression of kidney-specific cadherin in all the neoplastic cells, CK7 expression in 45% and PAX-2 expression in 60% of these cells. RCC and vimentin showed no reactivity within the tumor. The morphological features and immunohistochemical studies confirmed the diagnosis of a cystic renal oncocytoma.

Full Text:



  • There are currently no refbacks.