[Solitary Peripheral Pulmonary Squamous Cell Papilloma;Diagnostic Significance of 18F-fluorodeoxyglucose Positron Emission Tomography Findings].

The patient was a 79-year-old woman who had received enucleation of right pulmonary papilloma 7 years earlier. She experienced bloody sputum and was therefore referred to our hospital. Chest computed tomography revealed a mass shadow(21 mm) in the right upper lobe (S2). By bronchoscopy, there was no bulging lesion in the visible range. SCC and CEA increased to 6.4 ng/ml and 6.42 ng/ml, respectively. Whole-body 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) showed increased FDG uptake in the region of the right-lung mass shadow (maximum standardized uptake value 12.95). Since malignancy could not be ruled out, a wedge resection was performed. The post-operative histopathologic diagnosis was squamous cell papilloma. Our literature review showed 12 out of 14 cases with solitary papilloma of the peripheral lung to have increased FDG uptake. Ki-67 positive cells were confirmed in the basal layers of the epithelium, and active cell proliferation of the papilloma is likely to be a cause of increased FDG uptake.