Granular Cell Myoblastoma of the Bronchus: A Benign Lesion with a Potential for Rapid Growth

Abstract

To the Editor: Granular cell myoblastoma of the bronchus (GCM) is a relatively rare tumor. Only 46 cases of solitary and 2 cases of multiple lesions of the tracheobronchial tree have been described in literature.1Valenstein SL Thurer RJ Granular cell myoblastoma of the bronchus: case report and literature review.J Thorac Cardiovasc Surg. 1978; 76: 465PubMed Google Scholar We had the opportunity to observe a patient suffering from GCM for approximately one year before she consented to surgery. A 32-year-old obese black woman was admitted to Mary Thompson Hospital because of persistent productive cough and recurrent attacks of lung infections with fever, dyspnea and chest pain. Chest x-ray films revealed right lower lobe atelectasis. Fiberoptic bronchoscopy was performed on October 7, 1976, and revealed a patent but irregular lumen of the right lower lobe bronchus, with hypertrophy of the mucosa in a polypoid cauliflower fashion all around. Biopsy and brushing failed to yield a diagnosis. The patient refused surgery. On April 24, 1977, she was readmitted because of progression of her symptoms. Plain chest x-ray films and tomograms this time revealed a mass 4.5 × 4 × 3 cm in the right lower lobe area which was not present in the previous films. The patient still refused surgery and bronchoscopy. About three months later, on July 13, 1977, the patient was admitted again with a severe lung infection and at this time she was reexamined with the bronchoscope. The lumen of the right lower lobe bronchus, which was patent but irregular before, was now reduced to a pinpoint hole in the middle of a fleshy mass protruding from it and encroaching on the middle lobe orifice (Fig 1B). The patient was now convinced that she needed surgery. On July 22, 1977, a right posterolateral thoracotomy was performed. The entire right lower lobe appeared atelectatic and collapsed. A very hard mass was felt in the region of the right lower lobe bronchus. The artery to the lower lobe was completely overshadowed by the tumor mass which covered it and displaced it to a posteromedial position (Fig 1C). It did not seem possible to perform a conventional lower lobectomy without sacrificing the middle lobe bronchus. However, upon opening the bronchus anteriorly, without clamping, it was found that the fleshy mass in the lower lobe, though protruding from it, did not invade the posterior wall. Hence, bronchoplasty was performed whereby a flap of the posterior wall of the right lower lobe bronchus was used to close the bronchotomy (Fig 2E, F). The postoperative course was noneventful and to date the patient remains symptomfree and with no evidence of recurrence radiologically. Granular cell myoblastoma, though a benign tumor, seems capable of very rapid growth, as indicated in our patient. Within seven months, a tumor mass appeared on x-ray film which had not been present before. The mass grew within the bronchus, occluded the lumen almost totally, and started to encroach on the neighboring bronchial opening. It seems that surgery is the treatment of choice and is curative. The fact that the tumor is interbronchial and noninvasive would suggest that a bronchoplastic procedure rather than radical resection could be feasible in many cases to spare lung tissue and avoid respiratory insufficiency, especially in an obese, emphysematous patient,2Suzuki C Oshibe M Magashima Y Granular cell myoblastoma of the bronchus: report of a case with treatment by upper lobectomy and sleeve resection of the stem bronchus.J Thorac Cardiovasc Surg. 1971; 61: 271PubMed Google Scholar as the one presented here.