Follicular helper T-cell lymphoma: a B-cell-rich variant of T-cell lymphoma.
Follicular helper T-cell lymphoma is a recently described variant of T-cell lymphoma sharing the cell of origin with angioimmunoblastic T-cell lymphoma and with primary cutaneous CD4-positive small/medium T-cell lymphoma. To better characterize the morphologic and immunophenotypic features of follicular helper T-cell lymphoma, a series of 4 confidently diagnosed cases are analyzed. The overall morphologic pattern significantly overlaps with that of progressive transformation of germinal centers in 3 cases and with follicular hyperplasia in 1. Detection of large, clustered, atypical T-cells is an important feature differentiating follicular T-cell lymphoma from benign, reactive processes such as progressive transformation of germinal centers. The abnormal T-cells have an immunophenotype identical to that of follicular helper T-cells in all cases. Clonal T-cell populations are detected in all cases. A characteristic setting follicular T-cell lymphomas apart from most other T-cell lymphomas is the abundance of small, mature B-cells. Differences from angioimmunoblastic T-cell lymphoma include the absence of proliferating vessels or of Epstein-Barr virus-positive immunoblasts.
Laboratory Medicine, Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH.
S J
SJ
Ruiz
Laboratory Medicine, Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH. Electronic address: cottac@ccf.org.
C V
CV
Cotta
D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping; D008224:Lymphoma, Follicular / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D016411:Lymphoma, T-Cell, Peripheral / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism / Q000473:pathology*
Angioimmunoblastic T-cell lymphoma; Follicular T-cell lymphoma; Follicular helper T-cell; Peripheral T-cell lymphoma; T-cell lymphoma