HISTORY:

A 40-year-old male with history of tuberous sclerosis presents with 5 months of painless gross hematuria and mild left sided abdominal pain.

Abdominal MRI showed large masses in bilateral kidneys with areas of fat throughout the renal mass complexes. A large left renal mass appeared morphologically different, without internal fat and with a central stellate scar, measuring 14x11x16cm.

The patient underwent left nephrectomy with tissue sent for histopathological examination.s

GROSS:

Epithelioid angiomyolipomas are large (range 1-25, mean 8.7cm), predominantly solid pink-tan masses frequently containing areas of hemorrhage and necrosis.

Borders can range from well circumscribed to infiltrative, with possible extrarenal extension and involvement of renal veins.