[Surgical Cases of Solitary Lesion after Surgery for Primary Lung Cancer].

Lung nodules during postoperative follow-up of lung cancer are generally suspected to be its recurrence, but some cases are diagnosed as non-malignant disease. From January 2001 to November 2018, we experienced 5( 4.5%) new non-malignant lesions in 112 lung cancer patients who underwent a lung resection. The average period from first to second lung surgery was 36.2 months (range:3-64), and computed tomography findings before the second surgery were solid nodules in four cases and groundglass opacity in one case. The average maximum standardized uptake value of the lesions on fluorodeoxyglucose positron emission tomography was 4.29 (range:0-10.85). The diagnosis after the second surgery was pulmonary cryptococcosis in 2 cases, nontuberculous mycobacteriosis in 1 case, inflammatory mass in 1 case, and pneumonia in 1 case. The differential diagnosis between these diseases and lung cancer recurrence is discussed in the present study.