Metastatic extraocular sebaceous carcinoma with an occult primary.

The cytological diagnosis of sebaceous carcinoma is based on the aspiration of tumor lobules with extensive sebaceous differentiation. However, these tumors may show a spectrum of cells ranging from basaloid to well-differentiated sebaceous. Extraocular sebaceous carcinoma is an uncommon tumor. An occult primary at initial presentation has not been described previously. A 60-yr old woman was referred to the fine-needle aspiration (FNA) clinic with a submandibular mass. The cytological diagnosis was mucoepidermoid carcinoma. Histopathologically, it was a sebaceous carcinoma metastatic to the submandibular lymph node. No primary tumor was identified. Six months later, she presented with a nodule at the angle of her mouth and a recurrence of the submandibular swelling. FNA cytology (FNAC) and histopathologic examination revealed a primary cutaneous sebaceous carcinoma with submandibular lymph node metastasis. A metastatic sebaceous carcinoma in the submandibular region with limited sebaceous differentiation and occult primary is another pitfall in the cytomorphological diagnosis of mucoepidermoid carcinoma.