Cytomorphologic features of angiosarcoma on fine needle aspiration biopsy

To present the cytomorphologic features of angiosarcomas identified on fine needle aspiration biopsy, review the literature, and discuss the differential diagnosis and pitfalls involved in such cases.

Fine needle aspirate smears from 11 cases (1 hepatic, 3 breast and 7 subcutaneous/soft tissue lesions of angiosarcomas from eight patients were reviewed. All cases had histologic confirmation of angiosarcoma.

All aspirates were hypocellular, with predominantly single cells in a background of moderate to abundant amounts of blood. Nine cases had scattered inflammatory cells, primarily neutrophils, in the background. Six of the cases had rare small clusters of cells. The cells were oval, round or spindled, with eccentric, round to spindle-shaped nuclei and moderate to abundant amounts of pale blue-gray, vacuolated cytoplasm. The cells ranged from two to nine times the size of the background red blood cells. In four cases, malignant cells demonstrated intracytoplasmic hemosiderin deposits. Small nucleoli were identified in five cases, large nucleoli in one case and hyperchromasia in seven cases. Mitotic figures, erythrophagocytosis, acinarlike or vascular structures, and necrosis were not identified in any of the studied cases. In four cases, a definitive diagnosis of angiosarcoma was rendered on the fine needle aspiration specimen. In three other cases, the differential diagnosis remained between angiosarcoma and radiation change.

The presence of scarce single pleomorphic cells in a bloody background should raise the diagnostic possibility of angiosarcoma. A definitive diagnosis of angiosarcoma is often difficult to render due to the paucity of diagnostic cells unless intracytoplasmic hemosiderin deposits can be identified. Multiple aspirations are often needed in order to obtain diagnostic material. In the setting of radiotherapy, it may be impossible to distinguish angiosarcoma from radiation change, and biopsy should be recommended.