Primary renal osteosarcoma: A case report

Abstract

Primitive renal osteosarcoma is a rare sarcoma of the kidney with only 27 cases reported in the literature. Itshistogenesis is poorly understood. It occurs at an older age between the fifth and seventh decade of life witha male predominance. The clinical features are similar to other renal diseases. Imaging shows calcificationswithin a lumbar or flank mass. Histology describes a sarcomatous proliferation producing osteoid, mostoften at an advanced stage (pT4), which implies a poor prognosis. We report on the clinical and pathologicfeatures of a case of primary renal osteosarcoma in a 56-year-old man with stage IV disease. This is the 28^th case of primitive renal osteosarcoma reported in the literature, confirming the highly malignant natureof this tumor and the need for early diagnosis.