Medium-sized buccal mucosa defect reconstruction with buccal advancement flap in mucoepidermoid carcinoma ex pleomorphic adenoma: a case report.

[INTRODUCTION AND IMPORTANCE] Mucoepidermoid carcinoma (MEC) ex pleomorphic adenoma is a rare type of salivary gland cancer. Surgical resection remains the standard therapy for this malignancy. After tumor removal, larger defects may require a local, regional, or free flap, while smaller ones can be closed primarily. Managing medium-sized defects can be challenging, especially on the buccal mucosa.

[PRESENTATION OF CASE] A 47-year-old man had a buccal mucosa mass for 10 years, which gradually grew over a year and irritated his chewing. A 2.2×2 cm buccal mass was observed with telangiectatic and erythematous alterations in the surrounding mucosa. The preoperative tissue biopsy suggested salivary gland malignancy. The patient underwent surgical excision and a single-stage buccal advancement flap reconstruction, successfully closing the 4 cm defect. The final diagnosis was MEC ex pleomorphic adenoma. He reported mild discomfort during the first few months while opening his mouth. The patient had fully recovered after 6 months.

[CLINICAL DISCUSSION] This is the first case of MEC arising in a pleomorphic adenoma of the buccal mucosa. For low-grade and small-sized tumors, a single modality is appropriate for treatment. Local flaps such as buccal fat pad or musculomucosal flap can repair medium-sized defects. However, the buccal advancement flap provides effective functional and esthetic benefits, optimal healing conditions, and reduces complications risk.

[CONCLUSION] The buccal advancement flap is a valuable option for reconstructing medium-sized buccal defects up to 4 cm. The single-stage surgical procedure has been proven to yield minimal complications and provide a favorable outcome.