Epithelioid sarcoma: A clinicopathological study of 12 head and neck cases.

Objectives: To determine the clinicopathological features of epithelioid sarcoma presenting in head and neck region (HNES) and elucidate diagnostic key points and treatment options for HNES. Materials and Methods: A total of 12 HNES cases were collected in our department from 2010 to 2020. Their clinical information and pathological features were documented, and relevant follow‐up was performed. Immunohistochemistry was carried to analyze the protein markers of HNES. Results: Of the 12 HNES cases, 10 were primary tumors and 2 were metastasized from foot and shoulder, respectively. The patients with primary tumors were significantly younger than those with metastasized ones (22.7 vs 41.5, p =.0157), and male patients outnumbered female patients (3:1). Of all HNES cases, 9 were classic subtype, and 3 were proximal subtype. HNES patients had a poor prognosis, with 5‐year overall survival of 41.5% and 5‐year relapse‐free survival of 22.5%. A loss of INI1 was identified as the hallmark of HNES with 83.3% (10/12) of HNES cases presenting as EZH2 positive. Conclusions: HNES is more prevalent at younger ages and in males, has a poor prognosis, and exhibits a greater proportion of classic subtype than proximal subtype. EZH2 inhibitor has therapeutic potential in HNES. [ABSTRACT FROM AUTHOR]