A case report of myoepithelioma of the lung

Abstract

Myoepithelioma of the lung is extremely rare. Myoepithelioma is common in the salivary and mammary glands. Although it is known as a low-grade malignancy, it sometimes causes recurrence or distant metastasis. A 69-year-old female was referred to our hospital because of a pulmonary nodule detected on chest radiography. Computed tomography showed a round 13-mm nodule in the right upper lobe (S3). There was no evidence of lymph node swelling. Preoperatively, the nodule was suspected to be a benign tumor, and we performed right S3 segmentectomy. No malignancy was found in the frozen section intraoperatively. Considering immunohistochemical as well as histological findings, the pathological examination confirmed a diagnosis of myoepithelioma of the lung. Tumor necrosis and mitotic figures were inconspicuous, and there was no evidence of high-grade malignancy.