Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT)-type of the liver in a patient with hepatitis C virus infection.

We report a case of primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT)-type of the liver presenting as a solitary mass in a patient with hepatitis C virus infection. A 73-year-old male was referred to our hospital because of a solitary mass in the liver, which was identified by ultrasonography during a routine follow-up study for his hepatitis C virus carrier status. A fine-needle biopsy was performed and the mass was diagnosed as non-Hodgkin's lymphoma. A detailed investigation showed no evidence of lymphoma in other sites. Left lateral segmentectomy was performed. Histologic examination showed diffuse, monotonous infiltration of centrocyte-like cells that are CD 19(+), CD 20(+), sIgM-lambda(+), CD 3(-), CD 5(-), CD 10(-). The patient received no adjuvant chemotherapy and is alive and disease free 34 months after surgery.