Primary hepatic marginal zone B-cell lymphoma with mantle cell lymphoma phenotype.

We report a rare case of primary hepatic lymphoma, Stage II disease, in a 48-year-old male who had a solitary hepatic tumour measuring 4 x 4.5 x 3 cm. The tumour showed a nodular growth pattern and lymphoepithelial lesions with bile ducts. Some neoplastic nodules had a non-neoplastic atrophic germinal centre and/or a thin mantle cell layer. Morphologically, the neoplastic cells were centrocyte-like cells or intermediate lymphocytes. They expressed L26(CD20)+/LN-1(CDw75)+/-/LN-2(CD74)+/cyclin D1- and had a monotypic immunoglobulin of cytoplasmic IgM (kappa) on paraffin sections. The neoplastic cells or neoplastic nodules expressed surface IgM+/surface IgD+/-/Leu-1(CD5)+/DRC-1+/alkaline phosphatase+/B1(CD20)+/B4(CD19)- on fresh frozen sections. We therefore diagnosed this case as primary hepatic marginal zone B-cell lymphoma with mantle cell lymphoma phenotype. We confirm that it is difficult to differentiate extranodal marginal zone B-cell lymphoma (low grade B-cell lymphoma of mucosa-associated lymphoid tissue type; MALT lymphoma) and mantle cell lymphoma.