INTRODUCTION:Pulmonary fibromas and granular cell tumors are rare benign tumors of the lung. Treatment of these endobronchial tumors has traditionally been by surgical resection. We report the first case of an endobronchial fibroma and granular cell tumor (GCT) in the same patient with successful resection of the fibroma using electrocautery snare.
CASE PRESENTATION:A 54 year old man with hypertension and coronary artery disease presented with shortness of breath on exertion and non-productive cough for two months. He denied chest pain, fever, chills, or weight loss. There was no family history of lung disorders. He had an eighty pack-year smoking history. Physical examination was notable for decreased breath sounds in the right upper lobe. CT pulmonary angiogram demonstrated no evidence of pulmonary emboli, but did reveal a round-lesion in the right mainstem bronchus. Spirometry was normal with a normal flow-volume loop. Fiberoptic bronchoscopy under conscious sedation showed a large pedunculated, polypoid lesion partially occluding the right mainstem bronchus and extending proximally into the trachea. We were able to pass a 6.0 mm bronchoscope around the mass to the right upper lobe and bronchus intermedius. An electrocautery snare was placed around the pedicle of the lesion. The lesion was removed in its entirety. Argon plasma coagulation (APC) was applied to the base of the lesion. The rest of the airway examination was unremarkable. Pathologic evaluation showed a well-circumscribed 1.3 cm lesion containing sparse, bland appearing spindle cell proliferation in abundant myxoid stroma. No granular cell features or cytologic atypia were seen. Immunohistochemical (IHC) staining was positive for S-100, with strong cytoplasmic positivity for CD34 and bcl-2 antibodies, and negative for smooth muscle actin. These findings were consistent with a myxoid neurofibroma. The patient’s cough and dyspnea improved. A repeat bronchoscopy at nine months did not show any recurrence. However, a new flat, white lesion was noted in the right lower lobe bronchus. Endobronchial biopsies showed large cells with abundant, granular eosinophilic cytoplasm. IHC staining was positive for S-100 protein, and negative for the proliferation marker Ki-67. These findings favored a diagnosis of benign GCT.
DISCUSSIONS:Neurofibromas and granular cell tumors are both very rare lung lesions. Fibromas may be sporadic or associated with neurofibromatosis type 1 (NF-1), and can occur endobronchially or in the lung parenchyma. Treatment of endobronchial fibromas has traditionally been by surgical resection. In this case, an electrocautery snare allowed for safe resection of this lesion. Electrocautery employs heat generated by current that causes coagulation and carbonization of tissue. The most common complications of electrocautery are minor hemorrhage, airway perforation, stenosis, and cartilage damage. Cartilage injury in non-small cell lung cancer patients was more common when the probe was applied longer than three seconds. On follow-up, the patient was found to have an asymptomatic granular cell tumor. GCTs arise from the neural sheath and are most often benign. GCTs have a wide anatomic distribution, and may be multifocal when found in the lung. These lesions are usually small, white or yellow, and histologically have abundant eosinophilic cytoplasm with a granular appearance. GCTs have a good prognosis and bronchoscopic treatment is adequate, but recurrence after resection has occurred. Like fibromas, GCTs can be seen in NF-1 and malignant transformation has occurred with both tumors. However, this patient did not meet criteria for a diagnosis of NF-1.
CONCLUSION:Pulmonary neurofibromas and granular cell tumors are very rare lung lesions and have not previously been reported in the same patient. A neural sheath origin suggests these lesions may be related. In this case, we demonstrate that use of an electrocautery snare is a safe technique for resection of endobronchial fibromas with adequate hemostasis.
DISCLOSURE:Michael Ezzie, None.