Neurofibroma of kidney: an uncommon neoplasm and diagnostic dilemma with solitary fibrous tumor.

Neurofibroma of kidney is an extremely rare tumor. To our knowledge, only five such cases have been reported worldwide till date. Here, we report a solitary neurofibroma of right kidney in a 54-year-old woman. Radiological investigations (ultrasonography and computed tomography) detected a solid mass in the upper pole of right kidney and clinicoradiologically renal cell carcinoma was suspected. A radical nephrectomy was performed under diagnosis of cancer. Microscopically, tumor consisted of benign spindle-shaped cells accompanied by fibrous tissue. Differential diagnoses of neurofibroma and solitary fibrous tumor (SFT) were made on morphological features. Immunohistochemically, the tumor cells were positive for S-100 protein, but negative for CD34 and CD99. Thus, a diagnosis of neurofibroma was established.