Fine-needle aspiration cytology of angiomatoid malignant fibrous histiocytoma.

Angiomatoid malignant fibrous histiocytoma (AMFH) is a rare, low-grade malignant mesenchymal neoplasm that affects mostly the extremities of children and young adults. Excisional surgery is the adequate treatment. The cytologic, immunocytologic, and histologic features noted in two patients having AMFH are presented. Cytologic smears showed histiocyte-like cells dispersed and in clusters, in close relation with eosinophilic mesenchymal fragments in a bloody background with lymphocytes. The tumor cells showed mild to moderate anisocariosis, often with nucleolus and vast, fragile cytoplasm. A fibroblastic-like spindle to ovoid cell population was also present in one patient. Immunohistochemical results are most consistent with myofibroblastic cell differentiation. When accompanied by adequate clinical information and ancillary techniques, a specific preoperative cytologic diagnosis is possible.