TYPE: Medical Student/Resident Case Reports
INTRODUCTION: Mucoepidermoid carcinoma (MEC) is a rare malignant tumor originating from the submucosal bronchial glands, histologically identical to tumors seen in the salivary glands and represent 1-5% of bronchial adenomas and 0.2% of all lung tumors. Presentation can include cough, hemoptysis, wheeze, dyspnea and signs of upper airway obstruction (UAO). Optimal treatment is surgical resection.
CASE PRESENTATION: 21 yo female with obesity presented with progressive dyspnea and sensation of throat closure. She was diagnosed with asthma but despite standard therapies her symptoms progressed, resulting in frequent ER visits and hospitalizations. CT chest revealed a bronchial mass with left lung collapse. Bronchoscopy demonstrated a left mainstem (LMS) mass with complete LMS and 80% right mainstem obstruction. Given high-level obstruction, bronchoscopic tumor debulking was attempted but she was unable to be successfully jet ventilated. She was cannulated for VV-ECMO and underwent successful debulking using cryoablation, mechanical resection and argon plasma coagulation. She was decannulated and extubated the next day. Pathology showed a low-grade MEC with PET-CT showing 8mm extraluminal disease confirming the diagnosis of primary bronchial MEC. She underwent a pulmonary sleeve resection with negative margins. Given low grade pathology, no adjuvant radiation nor chemotherapy were indicated. Surveillance bronchoscopy demonstrated no recurrence or stenosis.
DISCUSSION: Primary bronchial MECs are rare and present with nonspecific symptoms often mimicking other respiratory diseases such as asthma. Chest x-ray may be normal or show hyperinflation, atelectasis or pneumonia. CT scans can visualize the tumor and predict grade based on location, shape, density and borders. MECs are subdivided into low-grade or high-grade tumors based on their histologic findings and staged based on TNM which correlate with aggressiveness and prognosis. Low-grade tumors with successful excision do not require adjuvant therapies. 5-year survival has been shown to be 90%. For MECs with signs of UAO, bronchoscopic tumor debulking is an effective bridge to definitive surgery. In situations where the extent of endobronchial involvement limits adequate ventilation, the use of ECMO is an option. While there is a paucity of literature on ECMO-supported bronchoscopic interventions, it is well known that bronchoscopy can be safely performed on patients receiving ECMO.
CONCLUSIONS: Pulmonary MECs are rare but should be considered in patients with evidence of UAO or those not responding to standard therapies for more common conditions. VV-ECMO assisted bronchoscopic interventions can be an effective tool to bridge patients with significant proximal obstruction to definitive surgical resection.
Reference #1: Song Z, Liu Z, Wang J, Zhu H, Zhang Y. Primary tracheobronchial mucoepidermoid carcinoma--a retrospective study of 32 patients. World J Surg Oncol. 2013 Mar 9;11:62. doi: 10.1186/1477-7819-11-62. PMID: 23497031; PMCID: PMC3599790.
Reference #2: Vadasz P, Egervary M. Mucoepidermoid bronchial tumors: a review of 34 operated cases. Eur J Cardiothorac Surg. 2000 May;17(5):566-9. doi: 10.1016/s1010-7940(0000386-9). PMID: 10814920.6.
Reference #3: Kim BG, Lee K, Um SW, Han J, Cho JH, Kim J, Kim H, Jeong BH. Clinical outcomes and the role of bronchoscopic intervention in patients with primary pulmonary salivary gland-type tumors. Lung Cancer. 2020 Aug;146:58-65. doi: 10.1016/j.lungcan.2020.05.016. Epub 2020 May 22. PMID: 32512274.
Disclosures: No relevant relationships by Peyman Benharash, source=Web Response
Speaker/Speaker's Bureau relationship with Boehringer-Ingelheim Pharmaceuticals Please note: $5001 - $20000 by Jaime Betancourt, source=Web Response, value=Honoraria
Speaker/Speaker's Bureau relationship with Vapotherm, Inc Please note: $5001 - $20000 by Jaime Betancourt, source=Web Response, value=Honoraria
Speaker/Speaker's Bureau relationship with Boehringer-Ingelheim Pharmaceuticals Please note: 2014-Present Added 04/21/2021 by Jaime Betancourt, source=Web Response, value=Honoraria
Speaker/Speaker's Bureau relationship with Vapotherm, Inc Please note: 2019-Present Added 04/21/2021 by Jaime Betancourt, source=Web Response, value=Honoraria
Advisory Committee Member relationship with Vapotherm, Inc Please note: 2020 Added 04/21/2021 by Jaime Betancourt, source=Web Response, value=Honoraria
No relevant relationships by Kevin Eng, source=Web Response
No relevant relationships by Patrick Holman, source=Web Response
No relevant relationships by Ryan Lau, source=Web Response
no disclosure on file for Jay Lee;
No relevant relationships by Catherine Oberg, source=Web Response
No relevant relationships by Scott Oh, source=Web Response
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