Background: Malignant vascular tumors are rare. Few studies have described cytomorphologic features of hemangioendothelioma and angiosarcoma on fine needle aspiration cytology (FNAC). Malignant vascular tumor with epithelioid morphology can create diagnostic difficulty, as the cytology may simulate that in other nonvascular malignant tumors. We describe epithelioid angiosarcoma, diagnosed on FNAC, in which a differential diagnosis of histiocytosis and inflammatory granulation tissue was considered.
Case: A 20-year-old man presented with forehead and scalp swellings. The forehead lesion was radiologiocally associated with a lytic lesion in the bone. FNA resulted in high cellular yield, and smears revealed prominent vascular pattern with endothelial cell atypia and histiocytoid/epithelioid neoplastic cells, occasional mitotic figures and a few cells displaying nuclear grooving. Smear background showed a significant number of neutrophils. Epithelioid hemangioendothelioma/angiosarcoma, histiocytosis and inflammatory granulation tissue were considered. A cytologic diagnosis of epithelioid angiosarcoma/epithelioid hemangioendothelioma was suggested and confirmed on histopathologic and immunohistochemical examination.
Conclusion: Cellular aspirates from malignant epithelioid endothelial tumors involving bone may be cytologically mistaken for histiocytosis and, rarely, inflammatory granulation tissue. However, prominent vascular pattern with striking endothelial cell atypia, presence of mitotic figures and careful search for presence of endothelial differentiation are helpful in accurate cytologic diagnosis.