A case of invasive mucinous adenocarcinoma presenting with massive bronchorrhea

An 80-year-old non-smoking woman was admitted to hospital due to persistent sputum production and dyspnea. She developed respiratory failure, and chest imaging revealed multifocal consolidation and cavities. Her respiratory status did not respond to antimicrobial treatment and progressively worsened, with massive sputum production of approximately 1 L per day, and she died 19 days after admission. The patient was diagnosed with invasive mucinous adenocarcinoma based on a postmortem needle biopsy of the lung. Clinicians should consider invasive mucinous adenocarcinoma in the differential diagnosis of patients who present with massive bronchorrhea and diffuse pulmonary cavity abnormalities.