Isolated bone marrow non-Hodgkin's lymphoma: A clinicopathologic study

Background: Isolated bone marrow non-Hodgkin's lymphoma (NHL) is rare, and determining the diagnosis is difficult. Patients: We describe four patients with apparent isolated bone marrow NHL. The features they had in common included fever, abnormal liver function, pancytopenia, polyserositis, neurologic symptoms, opportunistic infections, and a short, fatal course. Findings: Routine cytologic and histologic studies showed intermediate and large lymphomatous cells in the bone marrow, with a predominantly interstitial pattern. Immunophenotyping revealed three cases of T-cell and one case of B-cell NHL. Cytogenetic analysis demonstrated an abnormal clone in two patients. Conclusion: The diagnosis of isolated bone marrow NHL should be based on the examination of both bone marrow aspirates and biopsy specimens.