RT Journal Article SR Electronic T1 Rare cause of lung atelectasis in a young woman JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e227969 DO 10.1136/bcr-2018-227969 VO 12 IS 1 A1 Paula Inês Pedro A1 Dolores Canário A1 Miguel Lopes A1 Despina Argyropoulou YR 2019 UL http://casereports.bmj.com/content/12/1/e227969.abstract AB Pulmonary mucoepidermoid carcinoma is an extremely rare intrathoracic malignancy, comprising less than 1% of all lung tumours. These are very slow growing and are classified into low grade and high grade based on histological features. Surgical resection is the primary treatment with excellent outcomes, while chemotherapy or radiotherapy effectiveness is not known. Preoperative fluorine-18 fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) is useful for predicting tumour grade and postsurgical prognosis.A clinical case of a 31-year-old woman who presented with dyspnoea on exertion, cough and wheezing is reported. Imaging studies revealed a mass involving the left lower lobe bronchus and atelectasis. 18F-FDG PET/CT showed uptake in the described mass with a maximum standardised uptake value of 9.7. Complete surgical resection was performed, and pathological examination revealed a high-grade mucoepidermoid carcinoma with tumour-free margins. Adjuvant chemotherapy was given and there is no evidence of tumour recurrence.