Mucoid impaction presenting as a solitary pulmonary mass mimicking lung malignancy.

Mucoid impaction of the bronchi is an uncommon benign condition that can closely mimic pulmonary malignancy on imaging. A woman in her 50s with a remote history of chest wall chondrosarcoma presented with chest pain and was found to have a new pulmonary mass with satellite nodules. Computed tomography (CT) and fluorodeoxyglucose positron emission tomography (FDG-PET) findings raised concern for metastatic disease or primary lung cancer. Given the radiological suspicion and the patient's oncological history, surgical resection was undertaken. Intraoperative lymph node sampling was negative for malignancy. Histopathological examination of the lung specimen demonstrated dense mucoid impaction with eosinophils and Charcot-Leyden crystals, with no evidence of neoplasia. This case highlights the limitations of imaging alone in differentiating benign from malignant pulmonary lesions and reinforces the importance of histopathological confirmation before definitive oncological management.