Peripheral T Cell Lymphoma Associated with Hemophagocytic Histiocytosis Mimicking Malignant Histiocytosis / 대한임상병리학회지

ABSTRACT

BACKGROUND: Peripheral T cell lymphoma (PTCL), a prevalent form of non Hodgkin lymphomas in East Asia, can manifest fever, hepatomegaly, lymphadenopathy, pancytopenia and hemophagocytic histiocytosis (HPH). Similar clinicopathologic findings are also frequently encountered in reactive hemophagocytic syndrome (HPS) and malignant histiocytosis (MH) , thus diagnoses could be confused among them. With recent advancement of immunohistochemlal techniques, diagnostic accuracies have been improved and most cases of MH could have been reclassified as PTCL. In this study, we intended to delineate the lineage of atypical malignant cells in bone marrow of subjects which were previously diagnosed as MH or HPS with immunohlstochemical analysis and characterize clinlcophathologic findings of PTCL associated with HPH in the bone marrow. METHODS: Five cases dignosed as HPS, 3 as MH, 3 as presumed MH, and 7 as PTCL on bone marrow examination were enrolled in this study. We performed immunohistochemical stain for CD45, CD3, CD43, CD2O and CD68, then revised the diagnoses and summarized the clinical and morphologic features of PTCL associated with HPH. RESULTS: Eleven out of 18 cases were confirmed as PTCL which were previously diagnosed as MH(1), presumed MH(3) and PTCL(7). Eight cases of 11 PTCL showed HPH mimicking MH with infiltration of the atypical malignant cells, even if the proportion of atypical malignant cells was small on bone marrow aspirates. They manifested fever and hepatomegaly but didn't have lymphadenopathy at the early stage of disease. Subtypes of PTCL with HPH were PTCL, unspecifed (3), angioimmunoblastic T cell lymphoma (1) and undetermined (4). They showed poorer outcome in 3-month survival rate (25%) than in those with PTCL without HPH(100%). CONCLUSION: These results suggest that PTCL associated with HPH should be excluded from MH by immunohistochemical analysis. Considering that prognosis of PTCL with HPH is very poor, accurate and rapid diagnosis is needed for prompt treatment.