A case of hepatic pseudolymphoma observed without surgical intervention.

We report a case of liver pseudolymphoma that has been followed up without surgical resection after the diagnosis. A 63-year-old woman with a hepatic hypo-echoic lesion, 16mm in diameter was referred to our hospital. Laboratory data on admission were within normal limits. Serum HbsAg and HCVAb were negative. Abdominal computed tomography revealed an enhanced round lesion at the same location of the liver. Histopathological examination of the biopsy specimen demonstrated aggregation of the small round cells, lacking cytologic atypia or mitotic figures. These cells were B lymphocytes with staining of kappa and lambda light chains at equal frequency. Furthermore, monoclonal band was not detected by the polymerase chain reaction (PCR) method for the position of the third complementarity-determing region (CDR3) in the immunoglobulin heavy chain (IgH). These results suggested that the cells infiltrated in the lesion were polyclonal and benign nature. This case was observed carefully without surgical operation. During the course, Helicobacter pylori were successfully eradicated. Follow-up study after 18 months showed that the diameter of the tumor had decreased from 16mm to 8mm, suggesting no evidence of the malignant transformation.