Left Mainstem Bronchus Glomus Tumor of Uncertain Malignant Potential Managed by Repeated Bronchoscopic Ablations

Abstract

SESSION TITLE: Metastatic and Other Primary Lung Tumors SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Glomus tumors (GTs) are rare neoplasms arising from the modified smooth muscle cells surrounding arteriovenous anastomosis. Due to sparse or absent glomus bodies in the visceral organs, extracutaneous presentation of GTs are rare. We present a case of a man with left main bronchus glomus tumor managed with serial bronchoscopies. CASE PRESENTATION: A 53 year old man presented to the emergency department with daily episodes of hemoptysis. Computerized tomography evidenced a 11 x 7 mm lesion in the left distal carina and PET-CT did not detect areas of hypermetabolic activity. Bronchoscopy revealed a lobulated endobronchial lesion on the anterior wall of the left mainstem bronchus. Biopsy specimen was analyzed at the Joint Pathology Center in Maryland which showed: epithelioid cells with abundant eosinophilic cytoplasm, sharp cell borders arranged in sheaths, focal atypia with neoplastic cells demonstrating vesicular chromatin, all suggestive of glomus tumor. On repeat bronchoscopy, snare removal of a 1.5 cm smooth pedunculated lesion and cryoablation of the stump was performed. EBUS inspection showed submucosal extension (<1 cm) with no invasion of the external wall of the trachea or surrounding lymph nodes or vessels. Electron microscopy confirmed it as a glomus tumor with borderline mitosis figure of 5/50 on HPF. The specimen was SMA and vimentin positive, had increased KI-67 activity and unknown malignant potential with positive margins. Follow up endoscopy revealed a lobulated lesion with necrosis on the anterior wall of the left mainstem. Patient underwent serial cryoablation, with repeat surveillance showing a 0.5 cm x 0.3 cm fungating lesion and no mass was visualized on the fourth endoscopy. DISCUSSION: Contrary to our case, most GTs in the airway occur in the posterior wall, were mucous glands and vessels are numerous. The diagnosis of malignant GTs is reserved for tumors having: a size of >2 cm and subfascial or visceral location, atypical mitotic figures or marked nuclear atypia. This case had unknown malignancy potential due to the presence of mitotic activity and cellular atypia but lack of other criteria. Of reported cases, only 3 were identified as of unknown malignant potential. Historically, GTs were treated by surgical resection. Only 15 of the 49 described cases were treated endoscopically. Our case did not show recurrence at follow up, previous reports described normal findings after 6 years of surgical resection. CONCLUSIONS: In patients with tracheal glomus tumors who are poor surgical candidates or are not willing to undergo surgery, bronchoscopy tumor removal can be a feasible alternative. Reference #1: Fernandez-Bussy, S. Concomitant tracheal and subcutaneous glomus tumor: Case report and review. Respir Med Case Rep, 2015, 16, 81-5. Reference #2: Folpe AL. Glomus tumors. In: Fletcher CDM, Unni KK, Mertens F, editors. WHO classification of tumors: pathology and genetics of tumors of soft tissue and bone. Lyon (France): IARC Press; 2002. pp. 136-37. DISCLOSURE: The following authors have nothing to disclose: Felix Reyes, Michael Cutaia, Mohammad Al-Ajam, Fidelina De Soto Lapaix No Product/Research Disclosure Information