Bronchoalveolar carcinoma (adenocarcinoma) mimicking recurrent bacterial community-acquired pneumonia (CAP).

Depending on the community-acquired pneumonia (CAP) pathogen, host factors, and immune status, CAPs resolve on chest x-rays at different rates. CAPs that resolve more slowly than expected, or not at all, are termed "slowly or non-resolving CAPs." In contrast, recurrent CAPs may be due to host defense defects (eg, multiple myelomas) or post-obstructive bronchogenic carcinomas. There are a variety of noninfectious disorders that may mimic CAPs on chest x-ray: alveolar hemorrhage, pulmonary drug reactions, radiation pneumonitis, Wegener's granulomatosis, bronchiolitis obliterans organizing pneumonia, bronchogenic carcinomas, and lymphomas. Noninfectious mimics of recurrent CAPs include congestive heart failure, pulmonary emboli, infarctions, sarcoidosis, and systemic lupus erythematosus pneumonitis. We present the case of a middle-aged man who presented with recurrent right middle lobe and right lower lobe CAPs. Diagnostic bronchoscopy showed no bronchial obstruction, but open lung biopsy showed bronchoalveolar carcinoma (well-differentiated adenocarcinoma). Bronchoalveolar carcinomas presenting as post-obstructive or recurrent CAPs are rare because the spread is along tissue planes and not endobronchially. The case described demonstrates a rare cause of bronchogenic carcinoma mimicking recurrent CAP.