Unusual Presentation of Cryptogenic Organizing Pneumonia with Multiple Pulmonary Nodules Resembling Pulmonary Metastases: A Case Report

Cryptogenic Organizing Pneumonia (COP) is a lung disease characterized by multiple areas of consolidation with a subpleural distribution or ground-glass opacities, various atypical presentations of which have been reported in the literature.A 47-year-old male who presented with a cough underwent thoracic computed tomography, revealing multiple bilateral pulmonary nodules, located predominantly in the upper lobes.The nodules, the largest of which measured 20 mm, had varying border characteristics and some had frosted-glass densities.Positron emission tomography/computed tomography revealed several small lymph nodes without mediastinal pathological FDG uptake.A large number of nodules were identified in both lung parenchyma, some of which were calcified and with mildly elevated FDG uptake (early SUV max: 2.18, late SUV max: 3.14).The patient presented with an unusual radiological pattern of bilateral pulmonary nodules mimicking pulmonary metastases, however, histopathological findings were consistent with COP.This case highlights how the radiological and nuclear imaging characteristics of COP can potentially lead to misdiagnosis, such as malignancy.