Telangiectatic oncocytoma: A previously undescribed variant of renal oncocytoma

Objectives: To identify, describe, and investigate the clinical, radiologic, and pathologic features of 8 cases of telangiectatic oncocytoma. Methods: Fifty-three consecutive renal oncocytomas were reviewed for the telangiectatic pathologic features that were subsequently correlated with the demographic, clinical, and radiographic findings. Results: Telangiectatic oncocytoma accounted for 15% of the 53 renal oncocytomas collected in the past 7 years in our institution. On radiology, almost all presented as an enhancing mass and were suspicious for or consistent with a renal malignant tumor. Grossly, the tumors ranged from 2.4 to 6.0 cm (mean, 3.5 cm) and macroscopically were hemorrhagic spongy or multicystic masses without a central stellate scar. Microscopically, they were characterized by variably sized blood-distended spaces (<0.1-mm to 2- to 3-mm blood lakes) lined by typical oncocytoma cells and without evidence of degenerative changes. Conclusions: With its unique radiologic and pathologic presentations in comparison with classic renal oncocytoma, it is important to recognize this new variant of renal oncocytoma.