Reactive lymphoid hyperplasia of the liver.

A patient with reactive lymphoid hyperplasia of the liver was symptom free and had no underlying disease except for diabetes mellitus. The hepatic tumor was found by ultrasound examination at routine checkup. The preoperative diagnosis of the tumor was unsuccessful despite various radiological examinations. Histological examination of the resected tumor showed that it was composed of benign-appearing lymphocytic proliferations forming lymphoid follicles that included numerous germinal centers. The germinal center was mainly composed of B-cell marker, L26-positive lymphocytes, but a few T cells were also found. Lymphocytes surrounding germinal centers were mainly T-cell marker, UCHL1-positive T-cells, and a small number of B cells. The B cells in the lymphoid follicles were stained for both kappa and lambda light chains at equal frequency, indicating polyclonal and benign nature. A diagnosis of reactive lymphoid hyperplasia of the liver seems justified.