Pulmonary leiomyoma with iceberg tumor growth pattern: A case report.

Pulmonary leiomyoma is a rare disease, accounting for ~2% of cases of benign lung tumors. Pulmonary leiomyomas can be classified as tracheobronchial or pulmonary parenchymal, or as having an iceberg growth pattern, wherein the tumor extends into both the bronchial and pulmonary cavities. In the present report, a 41-year-old man complaining of sputum and discomfort during swallowing was referred to the National Center for Global Health and Medicine, because of an abnormal shadow on chest radiography and computed tomography (CT). Since the follow-up CT showed that the tumor in the third right lung segment had increased and progressed along the intra-bronchus over time, thoracoscopic right upper lobectomy was performed and leiomyoma was pathologically diagnosed. After resection, the symptoms of airway irritation improved. Since respiratory symptoms and radiographical findings are nonspecific with tracheobronchial and pulmonary parenchymal types of pulmonary leiomyoma, the identification of symptoms and determination of the extent of the lesion are necessary for treatment. In cases of iceberg growth pattern, in which the tumor extends into both the bronchial and pulmonary cavities, surgical resection should be considered.