Primary Cutaneous Follicle-Center B-Cell Lymphoma Michi M. Shinohara DEFINITION Primary cutaneous follicle-center B-cell lymphoma (PCFCL) is a neoplastic proliferation of germinal center B cells in the skin. PCFCL is one…
Approach to the Diagnosis of Cutaneous B-Cell Lymphomas Alejandro A. Gru Elaine S. Jaffe INTRODUCTION The diagnosis of cutaneous B-cell lymphomas (CBCLs) requires a careful evaluation of the clinical features,…
NK-Cell Leukemias/Lymphomas Youssef Youssef Alejandro A. Gru Aharon G. Freud INTRODUCTION Natural killer (NK) cells comprise a third major lineage of lymphocytes that are distinct from B cells and T…
Adult T-Cell Leukemia/Lymphoma Melissa Pulitzer DEFINITION Adult T-cell leukemia/lymphoma (ATLL) is an aggressive peripheral T-cell malignancy of a mature helper-T/regulatory-phenotype, which develops after chronic infection with human T-lymphotropic virus 1…
T-Cell Prolymphocytic Leukemia Alejandro A. Gru DEFINITION T-cell prolymphocytic leukemia (T-PLL) is a mature neoplasm of T cells with peripheral blood involvement. It is the most common subtype of mature…
Systemic Anaplastic Large Cell Lymphoma Alejandro A. Gru DEFINITION Anaplastic lymphoma kinase positive (ALK+) anaplastic large cell lymphoma (ALCL) is a mature T-cell lymphoma with expression of CD30 and ALK1…
Hydroa Vacciniforme and Hydroa Vacciniforme–Like Lymphoma Andy C. Hsi Carlos Barrionuevo-Cornejo DEFINITION Hydroa vacciniforme (HV) is a rare, intermittent ultraviolet (UV) light–induced vesiculopapular and scarring eruption in children associated with…
Extranodal NK/T-Cell Lymphoma, Nasal-Type Carlos Barrionuevo-Cornejo DEFINITION Extranodal NK/T-cell lymphoma, nasal-type (ENKTL) is an aggressive, extranodal necrotizing tumor associated with Epstein–Barr virus (EBV) infection. ENKTL invariably presents in the nasal…
Aggressive Cytotoxic Cutaneous T-Cell Lymphomas Ellen J. Kim Jacqueline M. Junkins-Hopkins INTRODUCTION Cytotoxic cutaneous T-cell lymphomas (CTCLs) are extremely rare non–mycosis fungoides (MF) cutaneous T-cell or natural killer (NK)-cell lymphomas…
Primary Cutaneous Peripheral T-Cell Lymphoma, Not Otherwise Specified Andy C. Hsi Amy C. Musiek András Schaffer DEFINITION Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) includes a heterogeneous group of non-Hodgkin…
