2015 年 61 巻 3 号 p. 177-181
Pleomorphic adenoma is the most common benign tumor of the salivary glands. Most cases develop in the region of the parotid gland, and few occur in the region of the sublingual gland. We describe our experience with a case of pleomorphic adenoma arising in the region of sublingual gland. Case patient: a 47-year-old man. Chief complaint: a tumor mass arising in the left side of the mouth floor. Facial expression: bilaterally symmetric, non-palpable regional lymph nodes. Present illness: a movable, elastically solid mass, measuring 25 × 14 mm, in the left side of the mouth floor. Findings on magnetic resonance imaging (MRI): on T2-weighted images, a slightly heterogeneous, high signal tumor mass in the left side of the mouth floor. Signal intensity as strong as muscle was observed on T1-weighted images. We diagnosed a sublingual gland benign tumor on MRI and suspected pleomorphic adenoma on fine-needle aspiration. We therefore performed extirpative surgery of the tumor, including the sublingual glands, from the oral cavity in May 2011. The histopathological diagnosis was pleomorphic adenoma. It has been 3 years since surgery, and no systemic or local abnormality has been found. A dequate follow-up for relapse and malignant transformation is considered essential.