Abstract

Cytologic findings of malignant cells obtained by fine needle aspiration from a huge retroperitoneal malignant fibrous histiocytoma were described. The smears contained numerous malignant cells, isolated or in clusters, in a bloody background. The malignant cells had abundant pleomorphic foamy or acidophilic cytoplasm with occasional multilobated vesicular nuclei and prominent nucleoli. Dual differentiation, both histiocytic and fibroblastic types, and neutrophilic inflammatory background were diagnostic of this neoplasm. The report indicated that study of aspiration cytology specimen from a soft tissue tumor was a valuable adjunct to histologic examination.