Myxofibrosarcoma of soft tissues: cytomorphologic analysis of a series.

Within the English literature, myxofibrosarcoma is a recently described entity. Although the histopathologic features have been reported, the cytomorphologic spectrum of myxofibrosarcoma has been far less documented. The cytologic findings of six fine-needle aspiration biopsy specimens (five primaries, one local recurrence) from six patients are described. The patients' ages ranged from 26-77 yr; there were four women and two men. The aspiration biopsy specimens ranged from slightly to markedly cellular. Although a myxoid granular to filamentous background was observed at least focally in all cases, the volume of the myxoid material was inversely proportional to the cellularity and grade of the tumor. Individual tumor cells were round to spindled, often displaying a wide range of cell shapes and sizes. Nuclei were generally large, pleomorphic, and hyperchromatic, frequently containing prominent nucleoli. Cytoplasm ranged from scant to dense and tapering. Multinucleated tumor giant cells were occasionally observed. In general, low- and intermediate-grade myxofibrosarcomas were more easily recognized in cytologic preparations. In contrast, high-grade myxofibrosarcoma was more difficult to specifically subtype and not easily distinguished from other adult pleomorphic sarcomas.