Presacral myelolipoma: CT findings.

The CT findings of a proven presacral myelolipoma are described, illustrated, and discussed. This lesion presents as an encapsulated mixed but predominantly fatty soft tissue mass located in the extraperitoneal retrorectal space. It occurs in asymptomatic individuals usually between the 5th to 8th decades, with a slight female predominance and without significant hematologic disturbances. This entity should be included in the differential diagnosis of a fat-containing presacral lesion. Familiarization with its typical CT appearance may permit a percutaneous needle biopsy diagnosis, avoiding unnecessary surgery.