[Diagnostic efficacy of 18F-fluorodeoxy glucose-positron emission tomography in multiple solitary pulmonary nodules]

A 73-year-old man was admitted to our hospital for evaluation of abnormal lung shadows in the left lung. Chest computed tomography revealed a cavitary lesion with irregular edges in the right S10 and a nodular lesion with well-defined margins in the left S6. Histological examination of a specimen obtained by transbronchial lung biopsy revealed squamous cell carcinoma in the right S10 but no significant findings in the left S6. Thirdly, 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) demonstrated that the nodular shadow in the left S6 was a low-uptake structure and that the cavitary lesion in the right S10 was a high-uptake lesion. We therefore considered that the nodular shadow in the left S6 was not one of neoplastic disease. Partial lung resection of the left S6 was carried out by videoassisted thoracoscopic surgery. The pathological diagnosis of the left S6 was epithelial granuloma with caseation. A culture of the same resected specimen was positive for Mycobacterium avium. The eventual clinical staging for the squamous cell carcinoma in the right S10 was cT2N0M0 (IB). Radical surgical treatment and right lower lobectomy were performed for the S10 lesion. We considered that 18F-FDG-PET was an effective noninvasive procedure for diagnosis of solitary or multiple solitary nodular shadows in the lung.