Fever, Dry Cough and Exertional Dyspnea: Pulmonary Lymphomatoid Granulomatosis Masquerading as Pneumonia, Granulomatosis with Polyangiitis and Infectious Mononucleosis.

Lymphomatoid granulomatosis (LYG) is a rare Epstein-Barr virus-associated lymphoproliferative disorder. The disease lacks specific clinical and radiological manifestations, which may delay a definitive diagnosis. We report the case of a 39-year-old man with pulmonary LYG who presented to a hospital after experiencing three months of fever, weight loss, dry cough and exertional dyspnea. He was initially misdiagnosed with pneumonia, granulomatosis with polyangiitis and infectious mononucleosis due to the non-specific manifestations of the disease. We herein present the clinical and radiological characteristics of this case and discuss the procedure for pathological diagnosis, which will likely help clinicians in making a timely definitive diagnosis of this disease.