Imaging findings of pulmonary granulomatosis with polyangiitis (Wegener’s granulomatosis): lesions invading the pulmonary fissure, pleura or diaphragm mimicking malignancy

Serkan Guneyli, Naim Ceylan, Selen Bayraktaroglu, Sercan Gucenmez, Kenan Aksu, Kenan Kocacelebi, Turker Acar, Recep Savas, Hudaver Alper

Granulomatosis with polyangiitis (GPA, formerly Wegener's granulomatosis), in which pulmonary involvement often predominates, is a multisystem granulomatous, necrotizing vasculitis that affects small and medium-sized vessels. In this study we evaluated various radiological findings of pulmonary GPA and focused on spiculated pulmonary lesions invading the pulmonary fissure, pleura or diaphragm mimicking malignancy. This retrospective study included 48 patients, aged 28-73 (mean, 47.3) years, who showed either histopathological diagnosis of GPA (n = 39) or elevated levels of the cytoplasmic anti-neutrophilic cytoplasmic antibody serum marker (n = 9) between January 2003 and December 2013. All patients received a chest computed tomography (CT), and the types of pulmonary lesions were defined and evaluated. Among the 48 patients, 33 had abnormal pulmonary findings on CT. The most commonly detected pulmonary lesion types were nodules and masses (n = 126) observed in 24 patients. Cavitation, necrosis, spiculation and invasion of the fissure, pleura or diaphragm were observed in 14, 9, 10 and 6 patients, respectively. Consolidation was found in 14 patients and thickening of bronchial wall in 8 patients. Pulmonary lesion types of GPA have a wide spectrum, potentially mimicking a high number of diseases including malignancy, infection and noninfectious inflammatory diseases. A spiculated lung lesion invading the fissure, pleura or diaphragm is mostly present in malignancy, but it can be also seen in GPA.