Primary angiosarcoma of the thyroid gland with recurrence diagnosed by fine needle aspiration: a case report.

Angiosarcoma of the thyroid is a rare and aggressive primary malignant tumor of the thyroid originally reported in patients from the Swiss Alpine region. Diagnosis of this tumor rests mainly on characteristic histopathological features of a malignant vascular tumor supported by immunopositivity for vascular markers e.g., CD31, Factor VIII, and CD34. Its cytological features, however, are not well-defined. We describe a case of primary angiosarcoma of the thyroid in a 48-year-old female, who presented with a rapidly enlarging neck mass associated with compressive symptoms. She had a history of hypothyroidism. The initial fine needle aspiration cytology of the neck mass was negative. She then underwent left hemithyroidectomy. Histologically, the tumor showed poorly differentiated malignant cells with eccentrically-placed nuclei, prominent nucleoli, and intracytoplasmic vacuoles admixed with mixed inflammatory cells. These showed immunopositivity for CD31 but were negative for CD34, Factor VIII, CK5/6, EMA, TTF-1, Thyroglobulin, Calcitonin, Melan A, and Calretinin. A diagnosis of poorly differentiated malignant tumor consistent with angiosarcoma was made. The patient was treated with radiation therapy but developed recurrence of the tumor. Second aspiration cytology of the recurrent tumor yielded hypocellular smears containing singularly dispersed atypical cells having eccentrically-placed nuclei with prominent macronucleoli and intracytoplasmic vacuoles within a background of inflammatory cells, consistent with recurrent angiosarcoma. Chemotherapy was started but she succumbed to the disease 7 months after diagnosis. The cytological, histopathological, immunohistochemical findings, and the clinical course are discussed.