ABSTRACT

A 49-year-old woman admitted to our hospital with a 3-month history of right flank pain without gross hematuria. Computed tomography scan of the abdomen showed that a 6x6x5 cm, contrast-enhanced mass was localized on the right renal pelvis. Histologically, a tumor composed of small ovoid to spindle shaped nuclei with indistinct cytoplasm was seen. Neoplastic cells showed diffuse immunoreactivity with CD34. It was diagnosed as solitary fibrous tumor. Solitary fibrous tumor of kidney is a very rare spindle cell neoplasm. It can mimic renal malignancy radiographically but almost all of renal solitary fibrous tumors are benign lesions.