A80-4-36 Mucoepidermoid Carcinoma: A Rare Cause of Hemoptysis

Abstract Introduction Mucoepidermoid carcinoma (MEC) is a rare form of primary lung cancer representing 0.1-0.2% of primary lung cancers. It typically presents in younger patients with approximately 50% of cases occurring prior to 30. It is often misdiagnosed due to nonspecific symptoms. It arises from minor salivary glands and is characterized by a mixture of mucous, intermediate and squamous cells. Rearrangement in the MAML2 gene is present in most cases. We present a case of MEC that presented with chronic cough and hemoptysis. Case Presentation The patient is a 21 year old female with a past medical history of minimal change disease who presented to the hospital with 2 months of cough, right sided pleuritic chest pain, and blood streaked sputum. She previously trialed budesonide/ formoterol for suspected asthma without improvement. She had no known tuberculosis exposures but traveled back and forth to Mexico. She denied smoking. Computed tomography (CT) of the chest was obtained revealing near complete right mainstem obstruction with post-obstructive pneumonia and tree-in-bud nodularity. The patient underwent bronchoscopy which revealed a fungating mass arising from the posterior wall of the proximal right mainstem, and was debulked. Pathology resulted in an unbalanced gene rearrangement involving the MAML2 gene with presence of a mixture of bland mucinous cells, intermediate polygonal cells, and squamous cells consistent with low grade MEC. PET-CT was obtained showing no evidence of distant disease but mild avidity in the station 7 lymph node. After discussion at tumor board, the patient was referred to thoracic surgery, who recommended sleeve resection of the right main stem bronchus. A pneumonectomy would be pursued if unable to obtain clear margins, along with marking for future radiation if needed. Discussion MEC is an extremely rare cause of primary bronchogenic carcinoma and a rare cause of hemoptysis. MEC is a challenging diagnosis due to nonspecific symptoms and slow progression. The diagnosis is heavily dependent on histopathology. The patient was diagnosed with low grade MEC due to the presence of MAML2 gene and absence of mitotic cells or necrosis. Patients with chronic cough and hemoptysis should undergo prompt imaging in order to identify endobronchial masses. Thoracic surgery intervention is crucial as there is excellent prognosis with complete resection. Conclusion MEC is a rare cause of primary lung malignancy and airway obstruction. It is important to keep a high index of suspicion for this malignancy in order to expedite bronchoscopy, biopsy, and resection. This abstract is funded by: None