Primary High-Grade Poorly Differentiated Angiosarcoma of an Intra-parotid Lymph Node.

Head and neck angiosarcoma is an infrequent malignant vascular tumor most commonly found in the skin and soft tissue of the head and neck. Most head and neck angiosarcomas are metastatic to cervical lymph nodes from other primitive location. We describe herein a case of primary high-grade poorly differentiated angiosarcoma arising in an intra-parotid lymph node, discuss the value of immunohistochemical stains for differential diagnosis, and review the literature concerning head and neck angiosarcoma. A 47-year-old man presented with a painless mass that had grown for a period of 6 months in the parotid area. The CT-scan revealed a left parotid lesion of 17 mm. Fine needle aspiration was considered suspicious for lymphoma or poorly differentiated carcinoma. A superficial parotidectomy was performed. On gross examination, the lesion was a well-defined, gray, homogeneous mass of 15 mm of diameter. Microscopic examination showed a normal parotid tissue and a poorly differentiated malignant neoplasm in an intra-parotid lymph node. The tumor had a pseudo-alveolar pattern, with large pleomorphic epithelioid cells, abundant eosinophilic cytoplasm, large vesicular nuclei, and one or more prominent nucleoli. Atypical mitoses were seen. Neoplastic malignant cells stained positive for Vimentin, CD31, D2-40, factor VIII, ERG, and partially for CD34. A positron emission tomography scan was made to search for a primary neoplasia, but no other tumor was localized. The diagnosis of primary high-grade, poorly differentiated, intra-parotid lymph node angiosarcoma was established.