Fever of unknown origin characterized by acute kidney injury and nephrotic syndrome diagnosed as intravascular large B-cell lymphoma of kidney: case report and literature review.

A 60-year-old Chinese female patient was admitted to the hospital with complaint of intermittent fever for more than seven months. The main clinical manifestations were acute kidney injury and nephrotic syndrome which developed into a hemophagocytic syndrome. The symptoms did not improve with antibiotics. Moreover, prednisone could only reduce the fever. Finally, a kidney biopsy showed many CD20-positive cells in the glomerulus and some in the peritubular capillaries. This led to a diagnosis of renal intravascular large B-cell lymphoma.