Perirenal myelolipoma diagnosed on imprint: case report and review of the literature.

Myelolipomas are benign tumors containing adipose tissue and hematopoeitic elements which occur most commonly in the adrenal glands. Extra-adrenal myelolipomas are uncommon with few cases of renal and perirenal myelolipomas in the literature. These cases may be difficult to diagnose based on radiology alone and intraoperative diagnosis can be extremely important in determining the course of surgery. Due to the lipomatous component of the tumor it may be technically difficult to prepare adequate frozen sections; this problem can be obviated by utilization of cytologic imprint preparations. We present a case of perirenal myelolipoma diagnosed intraoperatively utilizing cytologic imprint preparations stained with toluidine blue and hematoxylin and eosin.