Angiosarcoma of the head and neck: A clinicopathologic study with special emphasis on diagnostic pitfalls.

BACKGROUND AND AIMS: Angiosarcoma (AS) is a rare malignant vascular tumor that phenotypically and functionally recapitulate normal endothelium. They constitute approximately 2-4% of soft tissue sarcomas. We present 36 cases of head and neck AS diagnosed for 11 years at a tertiary care hospital in South India to analyze the clinical, pathological, and immunophenotypic profiles with special emphasis on their differential diagnoses and diagnostic pitfalls.

MATERIALS AND METHODS: Head and neck AS diagnosed from January 2006 to December 2017 were included. Clinical characteristics, treatment received, and follow-up data were obtained from electronic medical records. Hematoxylin and eosin (H&E)-stained slides and immunohistochemistry (IHC) slides were reviewed, and the histomorphological features, immunohistochemical staining, and their utility in resolving differential diagnosis were assessed.

RESULTS: Twenty-two females and 14 males were diagnosed with head and neck AS in the study period. Histomorphological patterns observed were mixed vasoformative and solid (n = 22), pure vasoformative (n = 13), and pure solid (n = 1). Neoplastic cells showed epithelioid, spindly, signet cell-like, clear cell, and rhabdoid morphology. CD31 was positive in 100% of cases, and CD34 was positive in 40% of cases. Differential diagnoses included melanoma, rhabdomyosarcoma, and large-cell lymphoma. Surgery, radiotherapy, and chemotherapy were the treatment modalities used. Twelve patients developed local recurrence, and 12 patients developed metastasis on follow-up. Twenty-five patients died of disease, on an average of 24 months after diagnosis.

CONCLUSION: Head and neck AS pose a significant diagnostic challenge due to their broad morphologic spectrum. Proper clinicopathologic correlation is necessary to avoid misdiagnosis.