The labyrinth of pyrexia of unknown origin: a case of intravascular diffuse B cell lymphoma

Hemophagocytosis-Related (Asian Variant) Intravascular Large B-Cell Lymphoma in a Hispanic Patient: A Case Report Highlighting a Micronodular Pattern in the Spleen

OBJECTIVES

We report a case of hemophagocytosis-related (Asian variant) intravascular large B-cell lymphoma (IVLBCL) in a patient of Western origin initially diagnosed by splenectomy with diffuse large B-cell lymphoma (DLBCL) with a micronodular pattern. The clonal relationship between these two DLBCL subtypes is also investigated.

METHODS

Hemophagocytosis-related (Asian variant) IVLBCL was identified at autopsy in a 62-year-old Hispanic woman, in North America, following an antemortem diagnosis of massive splenic involvement by DLBCL with a micronodular pattern, a feature not expected of IVLBCL.

RESULTS

These two apparently distinct lymphoma types demonstrated similar immunophenotypic profiles and IgH gene rearrangements of identical size suggesting a clonal relationship. The 2008 WHO classification system describes IVLBCL in the spleen as having a sinusoidal pattern.

CONCLUSIONS

Our observations provide the first molecular genetic support for a seemingly underrecognized micronodular pattern of IVLBCL in the spleen and further support the proposal of a "mixed variant" of IVLBCL with concomitant "intravascular" and "solid" phases of disease.

Peripheral blood hemophagocytosis in an unusual lymphoma

We describe a patient with fever, pancytopenia, and hepato-splenomegaly associated with the finding of neoplastic lymphoid cells and histiocytes with hemophagocytosis in the peripheral smear; the diagnostic features were suggestive for a biological overlap between a large B-cell lymphoma with intravascular involvement and the Asian variant of intravascular B-cell lymphoma.