CT FINDINGS OF RETROPERITONEAL MALIGNANT MESENCHYMOMA

Malignant mesenchymoma (MM) is a rare mesenchymal neoplasm which, by d efinition, demonstrates at least two distinct types of malignant mesen chymal differentiation. We present the computed tomographic (CT) findi ngs of a 42-year-old female with a pathologically proven retroperitone al MM consisting of osteoid production combined with foci of liposarco ma and Kaposi sarcoma. MM should be considered along with extraosseous osteosarcoma and teratoma in the differential diagnosis for unusual l arge heterogeneous retroperitoneal masses with massive calcification.