Intrathoracic granular cell myoblastoma.

Intrathoracic granular cell myoblastoma (GCM) is most commonly a benign neoplasm of Schwann cell origin that occurs in the large airways, the segmental bronchi, and rarely in the mediastinum. The tumor predominantly affects blacks during the fourth decade, and shows no sex predilection. Tracheobronchial GCM most commonly produces cough and chest pain, with focal consolidation or atelectasis shown on chest x-ray films. Extraesophageal mediastinal GCM produces few or no symptoms, and should be included in the differential diagnosis of a posterior mediastinal mass. Computerized tomography is helpful in evaluating the extent of the lesion, defining its relationship to adjacent structures, and planning the therapeutic approach. The diagnosis of tracheobronchial GCM usually can be made by bronchoscopy and/or biopsy. Treatment remains controversial, but most studies suggest surgical or endoscopic resection as the treatment of choice. The prognosis of intrathoracic GCM is good but is dependent upon complete removal.