Invasive Mucinous Adenocarcinoma Presenting as Cavitary Lung Disease: A Case Report and Narrative Review

Invasive mucinous adenocarcinoma (IMA) is a rare subtype of lung adenocarcinoma that often presents with non-specific or misleading radiographic findings. We report a case of a 71-year-old female patient, non-smoker, who presented with progressive dyspnea on exertion and chronic cough unresponsive to multiple antibiotic regimens. Imaging revealed bilateral cavitary lung lesions. Comprehensive infectious and autoimmune evaluations, including bronchoscopy with bronchoalveolar lavage, were negative, and transbronchial biopsy was non-diagnostic. A surgical lung biopsy ultimately confirmed IMA. This case underscores the diagnostic challenges posed by cavitary IMA, which may resemble benign infectious or inflammatory processes, particularly in patients without conventional risk factors, leading to delayed diagnosis and treatment.