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Special Feature
July 2002

Image of the Month

Author Affiliations

GRACE S.ROXYCKIMDFrom the Metropolitan Group Hospitals General Surgery Residency Program, Chicago, Ill (Drs Raftopoulos and Lee); the Department of General Surgery, St Francis Hospital at Evanston, Evanston, Ill (Dr Byrne); and the General Surgery Program, University of Illinois at Chicago (Dr Byrne).

Arch Surg. 2002;137(7):865-866. doi:

A 62-YEAR-OLD otherwise healthy man was seen for persistent right flank pain of 2 years' duration. Physical examination findings revealed fullness of his right lower quadrant and anterior thigh without any tenderness. A contrast-enhanced computed tomography (CT) scan of the abdomen, pelvis, and thigh demonstrated a large, well-circumscribed, homogeneous mass anterior to the right iliopsoas muscle that was extending from the inferior pole of the right kidney to the anterior midthigh. The right colon and small bowel were displaced medially (Figure 1).

The patient underwent exploration through a right flank incision that was extended vertically to the right groin and proximal thigh. The mass was encapsulated and found to be loosely adherent to the right iliopsoas muscle and femoral nerve. The tumor was removed en bloc. It weighed 790 g and measured 20 × 15 × 10 cm (Figure 2). Microscopic examination of the mass showed mature adipocytes without any mitoses or invasion. The patient had an uneventful recovery.

What Is the Diagnosis?

A.Retroperitoneal liposarcoma

B.Retroperitoneal lipoblastoma

C.Retroperitoneal lipoma

D.Retroperitoneal hibernoma