An Unusually Aggressive Large Cell Carcinoma of the Lung: Undiagnosed until Autopsy.

Large cell carcinoma (LCC) of the lung has a rapid mean volume doubling time (VDT) of around 67-134 days. In some cases of LCC where the VDT is extremely rapid, clinical presentation may mimic acute lung pathologies such as pneumonia. We describe a rare presentation of an aggressive LCC of the lung with an estimated VDT of around two weeks. A 52-year-old male with a history schizophrenia presented with fever, cough, and dyspnea for three weeks duration. His medical history was significant for a recent admission six weeks before current presentation for myocardial infarction (MI) and pneumonia. Chest radiograph during the current admission showed a new right lung infiltrate and he was treated for healthcare-associated pneumonia. However, the patient developed acute respiratory failure due to right lung collapse requiring intubation and mechanical ventilation. An urgent bronchoscopy revealed an obstructing endobronchial mass in right mainstem bronchus. A computed tomography (CT) scan of the chest showed encasement of right upper and lower lobe bronchus with extensive mediastinal lymphadenopathy. The patient expired within the next 24 hours. The autopsy showed undifferentiated LCC of lung metastatic to the regional lymph nodes. Of note is the fact that the patient had CT chest in his prior admission which showed no signs of lung or mediastinal mass. We report a case of LCC which manifested as pneumonia over a six-week period with a calculated doubling time of 14.1 days. Oxidative stress secondary to recent MI and schizophrenia may have a role in the unusual aggressiveness in this case.