B-cell non-Hodgkin's lymphomas (B-cell NHLs) showing a proliferation of small-to medium-sized neoplastic cells have a strong tendency to infiltrate the liver. In particular, small lymphoma cells are capable to circulate and recirculate in the body and to leave the microcirculation in several organs. The most common B-cell NHL is chronic lymphocytic leukemia of the B-cell type. In this slowly progressing neoplasia, the liver is almost always involved. Accumulation of neoplastic cells causes hepatomegaly, a typical and frequent finding, with liver weights slowly increasing over time to sometimes reaching several kilograms. The exterior aspect of the liver may become grayish white, and the cut surface shows numerous small whitish nodules. The histologic substrate is markedly enlarged portal tracts which are densely infiltrated by small neoplastic lymphocytes. In long-standing disease, larger nodular lesions can develop, mimicking metastatic disease. A similar type of liver involvement is seen in the rare B-cell prolymphocytic leukemia. Focal and nodular hepatic infiltration is also observed in follicular NHL, mantle cell lymphoma, and extranodal marginal zone B-cell NHL of mucosa-associated lymphoid tissue/MALT. Chronic B-Cell Lymphocytic Leukemia (Small B-Cell Lymphocytic Lymphoma; B-CLL/SLL) ICD-O code 9823/3 play a role for the survival of follicular neoplastic B cells (Amé-Thomas et al. 2012).