Primitive multipotential primary sarcoma of bone (Polyhistioma) or carcinosarcoma metastatic to bone?

摘要

The pictures shown were taken from an axillary lymph node of a 3 3-year-old man who presented with an ovoid lesion (1.6 cm in diameter) in the proximal aspect of the left femur, an ulcerated lesion in the skin of right forearm, and axillary lymphadenopathy. Abiopsy of the axillary lymph node was performed. This showed massive metastatic involvement by a largely undifferentiated neoplasm composed of small- to medium-sized round cells with focal rhabdoid features, associated with foci of bone formation and squamous differentiation (Figures 1-3). Under the assumption that the femoral lesion was the primary tumor and that the skin and axillary node represented metastatic deposits, the diagnosis was in favor of primitive multipotential primary sarcoma of bone (polyhistioma).