What is IgM Flare

“T and NK-cell lymphoid proliferations and lymphomas” comprise nine groups with distinct cell origins, differentiation states, clinical features, localization, and cytomorphology. Most correspond to specific T or NK lineage. Still, few have a hybrid or indeterminate phenotype, including extranodal NK and T-cell lymphoma, EBV+ nodal T/NK-cell lymphoma, chronic active EBV disease, and severe mosquito bite allergy. The distinction between T- and NK cells is sometimes unclear. The main categories are Mature T-cell and NK-cell leukemias, Primary cutaneous T-cell lymphoid proliferations and lymphomas (CTCL), Intestinal T- and NK-cell lymphoid proliferations and lymphomas, Nodal T-Follicular Helper Cell Lymphomas, Peripheral T-cell lymphomas (PTCLs), EBV-related mature T-cell and NK-cell neoplasms, and Extranodal NK/T-cell lymphoma (ENKTL). HL comprises classical HL (cHL) and nodular lymphocyte predominant HL (NLPHL) subtypes.