B cell lymphoma-associated hemophagocytic syndrome (B-LAHS) is clinically characterized by hepatosplenomegaly and bone marrow invasion without lymphadenopathy and skin lesions. Several cases of B-LAHS have been reported to demonstrate histopathologic findings of intravascular lymphomatosis (IVL), which in Western countries is characterized by a high rate of skin involvement and, rarely, bone marrow involvement and hemophagocytosis. Here we describe two interesting cases of B-LAHS. One patient was a 52-year-old woman whose bone marrow showed proliferation of large CD20-positive cells and hemophagocytosis at presentation. Combination chemotherapy was not effective, and the patient died of progressive disease. At autopsy, the lymphoma cells showed extravascular proliferation in many organs such as the bone marrow and liver, whereas in the adrenal glands, the lymphoma cells showed intravascular proliferation. The other patient was a 50-year-old man who had swellings of the bilateral kidneys and adrenal glands at presentation. Skin involvement by large lymphoma cells, a rare complication of B-LAHS, was observed. At autopsy, there was no evidence of IVL. Both of these patients showed high fever and cytopenia, and the disease took an aggressive clinical course, as in other reported cases of B-LAHS.