Abstract
Although mucoepidermoid carcinoma (MEC) is the most diagnosed malignancy of the salivary gland, it rarely localises to the bronchus, accounting for only 0.1-0.2% of all primary lung malignancies. Of those pulmonary MECs, most are found in segmental or lobar bronchi, and they are rarely found in mainstem bronchi, highlighting the novelty of this presentation for thoracic specialists. We present a case report of a seven-year-old female who underwent a carinal resection and a right upper lobectomy for the management of an endobronchial MEC causing right middle lobe (RML) obstruction. Intraoperatively, an exophytic mass originating from the junction of the right main bronchus and bronchus intermedius was identified, causing a partial obstruction of the RML bronchus. Frozen sections demonstrated clear margins and follow-up bronchoscopies have been unremarkable. Given their rarity, endobronchial MECs can be diagnostically difficult and cause uncertainty with respect to their management. Low-grade tumours have a much more favourable prognosis than their high-grade counterparts, with surgical resection being the gold standard of care. Therefore, the index of suspicion, time to diagnosis, and definitive treatment are critical to the outcome.