Rapidly Growing Vascular Mass Within the Thyroid. Angiosarcoma.

A woman in her 80s with a previous diagnosis of a multinodular goiter was referred for exertional dyspnea and chest discomfort. Her medical history was significant for gastroesophageal reflux disease, hypertension, stable angina, and obstructive sleep apnea for which she was using continuous positive airway pressure therapy at night. A repeated computed tomographic (CT) scan, when compared with a study 3 years prior, indicated clinically significant growth. A positron emission tomographic/CT scan was significant for increased metabolic activity in the mass. Surgical intervention was recommended for alleviation of symptoms and definitive diagnosis. A left thyroidectomy with partial right thyroidectomy (Figure, A) and a left modified neck dissection (levels II-IV) were performed. Gross examination revealed an encapsulated, 11.0 × 8.4 × 8.2-cm, tan-orange, predominantly hemorrhagic, necrotic nodule without grossly identifiable thyroid parenchyma (Figure, B). Extensive sampling revealed pleomorphic epithelioid cells with enlarged, hyperchromatic nuclei, irregular nuclear membranes, and increased mitotic activity (Figure, C). There was evidence of angiogenesis and formation of nests around areas with organizing hemorrhage. Tumor cells showed strong membrane reactivity for CD31, confirming an endothelial origin of the lesion (Figure, D). Adjacent thyroid parenchyma showed multinodular goiter and chronic lymphocytic thyroiditis. The neck dissection revealed normal lymphatic contents. Intraoperative photograph A