T-lymphoblastic leukemia/lymphoma with interfollicular growth pattern and Castleman-like morphologic features
Indolent T-lymphoblastic proliferation (iT-LBP) is a recently recognized benign pathologic condition commonly associated with Castleman disease. The lymph node of this condition shows preserved lymphoid architecture with proliferation of nonclonal T-lymphoblasts in the interfollicular area. iT-LBP is a rare condition and a diagnosis of exclusion. As a rule, it requires sophisticated techniques to exclude T-lymphoblastic leukemia/lymphoma (T-LBL/L). We present an unusual T-LBL/L in a lymph node mimicking iT-LBP. The case showed preserved nodal architecture, morphologic features of hyaline vascular Castleman disease, proliferation of T-lymphoblasts in the interfollicular area, and no clonal T-cell receptor gene rearrangement. The follow-up lymph node specimen excised 6 months later showed full-blown lymphoblastic lymphoma with an abnormal karyotype, near-early-T-precursor phenotype, partial CD19 expression, and SETD2 mutation.
Journal of Hematopathology
T-lymphoblastic leukemia/ lymphoma; Hyaline vascular Castleman disease; Indolent T-lymphoblastic proliferation
Li, W., Kats, A., Cooley, L. D., Farooqi, M., August, K. T-lymphoblastic leukemia/lymphoma with interfollicular growth pattern and Castleman-like morphologic features Journal of Hematopathology 14, 163-169 (2021).