The chest radiograph in the diagnosis of atypical nephritis due to infectious mononucleosis

A four-year-old boy developed oliguria, proteinuria and hypocomplementemia, without hematuria, in the course of proven infectious mononucleosis. A chest radiograph revealed a mild cardiomegaly, prominent pulmonary vasculature and pleural fluid. These abnormalities were compatible with acute glomerulonephritis and were in support of this clinical diagnosis in spite of the absence of hematuria.