Rapidly Progressive Mucoepidermoid Carcinoma in an Adult Patient: A Case Report.

Among salivary gland malignancies, mucoepidermoid carcinoma (MEC) often arises in the parotid gland and is less commonly found in the submandibular gland. This case report describes a 53-year-old Asian male patient presenting with a two-month history of insidious left submandibular swelling that progressed to pain in the preceding 10 days. Clinical examination revealed a firm, 3.5 cm x 2.5 cm mass with sublingual extension. Fine-needle aspiration cytology suggested salivary gland malignancy, confirmed by histopathological and immunohistochemistry analysis. To optimize access, surgical management involved en bloc resection of the left submandibular and sublingual glands with 1.5 cm margins, modified radical neck dissection (type III), and extraction of the left lower teeth from the lateral incisor to the second premolar. Histopathology confirmed intermediate-grade MEC with clear margins and focal perineural invasion. At follow-up, the patient remained disease-free with excellent functional outcomes, avoiding adjuvant radiotherapy. This case underscores the efficacy of multimodal diagnosis and tailored surgery for submandibular MEC, emphasizing the need for vigilant surveillance.