Mucinous adenocarcinoma is a rare lung cancer that can mimic the appearance of infectious pneumonia on imaging. The present report describes the case of an 88-year-old man who presented with a cough that was not responsive to treatment. Based on chest X-ray findings consistent with pneumonia, he was treated with oral antibiotics. After the patient’s symptoms did not improve, a computed tomography scan was performed, which showed a confluent consolidation in the left lower lung and a cavitation suggestive of pneumonia. The patient was then admitted to the hospital to receive intravenous antibiotics. Although his cough continued, laboratory findings were within normal ranges and bacterial cultures were negative. He underwent two bronchoscopy procedures with bronchoalveolar lavage and was diagnosed with parainfluenza and rhinovirus/enterovirus, for which he was treated with prolonged antibiotics and steroids. His symptoms still failed to improve, and a bronchoscopy with cryobiopsy was performed, with a positive result for mucinous adenocarcinoma. This case illustrates the need to distinguish mucinous adenocarcinoma from pneumonia to improve the early diagnosis of this rare cancer and patient outcomes.

Pulmonary sclerosing pneumocytomas are benign tumors. These tumors are often found incidentally and can be challenging to distinguish from lung malignancies. Here, we describe the case of a 31-year-old woman who presented with an incidental finding of a lung nodule in the lingula. She was asymptomatic and had no history of cancer. Positron emission tomography showed [18F] fluorodeoxyglucose (FDG) uptake in the nodule but no FDG-avid mediastinal lymphadenopathy. In view of these findings, a bronchoscopy was performed, and biopsy samples were taken. The final pathological diagnosis revealed a sclerosing pneumocytoma.