A Case of Pulmonary Pleomorphic Carcinoma Complicated by Lung Abscess and Organizing Pneumonia, Which Had Been Interpreted as Medically-intractable Severe Abscess and Pneumonia

Abstract

Case. A 67-year-old man initially presented for further examination of a tumor shadow in his right upper lobe, detected during a health check. A forceps biopsy via bronchoscopy revealed necrosis only and no specific diagnosis was obtained. Following this, he was referred to our hospital. His chest radiography and contrast-enhanced computed tomography (CT) showed an infiltrative shadow with an air-bronchogram, and a low-attenuation area in the infiltrates. A percutaneous biopsy under ultrasonic guidance detected two species of bacteria and necrosis, with no evidence of malignancy. We diagnosed lung abscess with bacterial pneumonia, and treated him with antibiotics (piperacillin/tazobactam, 13.5 g/day) for two weeks. However, chest CT showed exacerbation of the infiltrative shadows. We performed a right upper lobectomy because we thought his disease was medically intractable. Pathological examination of the resected material revealed pleomorphic carcinoma with suppurative inflammation inside the tumor and extensive organizing pneumonia around the tumor. Conclusion. This was an instructive case on the differential diagnosis between pleomorphic carcinoma and a lung abscess, and that between bacterial and organizing pneumonia.