Aspiration cytopathology of epithelioid angiosarcoma

Epithelioid angiosarcoma (EA) is an uncommon neoplasm readily mistaken for carcinoma. In contrast to the histopathology of this tumor, the cytopathology as obtained using fine-needle aspiration (FNA) biopsy has rarely been described.

Three patients with histologically and immunohistochemically proven EA each underwent FNA using standard technique before surgical resection.

Aspirate smears were obtained from 3 males (ages 47, 63, and 15 years) each of whom presented with a solitary palpable soft tissue mass, 1 from the left calf and 2 from the right popliteal region. No patient had a history of malignancy or had been exposed to prior radiation therapy. Smears were relatively hypocellular due to the dilutional effects of abundant blood. Cells were scattered on slides primarily in a single cell dissociated pattern; small aggregates were present in a fraction of the slides. Malignant cells generally monotonous in size and averaging three to four times the dimension of a mature lymphocyte had a rounded so-called epithelioid configuration. Cells possessed primarily rounded, single nuclei often eccentrically placed, with some anisokaryosis, and smooth nuclear borders. Binucleated cells with mirror-image nuclei were much less frequent, and cells with three or four nuclei were even more scarce. Cells contained large single nucleoli or more often multiple misshapen smaller nucleoli. Cytoplasm was abundant and finely granular in virtually all cells. In some, the cytoplasm acquired a central spheric density thus producing a "rhabdoid" appearance that was only seen with air-dried Diff-Quik (Fisher Scientific, Biochemical Sciences, Inc., Swedesboro, NJ) stained smears. Mitoses were readily found. Immunostaining of the cell block in one case permitted a specific diagnosis of EA before subsequent surgical excision.

Epithelioid angiosarcoma may display a rhabdoid morphology in FNA biopsy smears, and this cytopathology can closely mimic that of nonsmall carcinoma, malignant melanoma, and other epithelioid types of soft tissue tumors. Immunophenotyping is essential for definitive diagnosis. Cancer (Cancer Cytopathol)