Distinct morphologic, phenotypic, and clinical-course characteristics of indolent peripheral T-cell lymphoma

Abstract

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) consists of a heterogeneous group of lymphomas. Patients generally show an aggressive clinical course and very poor outcome. Although the 2008 World Health Organization classification of PTCL-NOS includes 3 variants, low-grade lymphoma is not included. Of 277 PTCL-NOS cases recorded in our consultation files, we examined the clinicopathologic characteristics of 10 patients with T-cell lymphomas composed of small-sized cells with slight nuclear atypia. Eight patients showed extranodal involvement (5 patients, spleen; 3 patients, thyroid), and 5 patients were at clinical stage I or II. Histologically, all samples presented diffuse infiltrate of small lymphoid cells, with few mitotic figures. Immunohistologically, all samples were positive for CD3, and CD20 was detected in 5 samples. All samples showed a low Ki-67 labeling index (mean, 1.05%), and 7 samples were positive for central memory T-cell markers. Clonal T-cell receptor γ chain and/or α-β chain gene rearrangements were detected in all 10 patients. Five patients received chemotherapy, whereas for 3 patients, treatment consisted only of observation following surgical resection of the spleen or thyroid. Nine patients were alive at a median follow-up time of 19.5 months, whereas 1 patient died of an unrelated disease. The present study strongly indicates that T-cell lymphoma with small-sized lymphoma cells and a low Ki-67 labeling index is a distinct variant. Recognition of this novel lymphoma subtype, which should not be defined merely as PTCL-NOS, should be seriously considered.

A Unique Case of an Indolent Myometrial T-Cell Lymphoproliferative Disorder with Phenotypic Features Resembling Uterine CD8+ Resident Memory T Cells

“…In the literature, cases of extranodal T-cell lymphoproliferation have been published as case reports or series [20,21,22,23,24]; they are characterized by clonal TCR rearrangement, non-activated cytotoxic (TIA1+/granzyme B-) CD8+ T-cell phenotype and no aberrancies in the remaining T-cell markers. Notably, only few of them presented with localized disease and none with uterine involvement.…”

Protocadherin γ A3 is expressed in follicular lymphoma irrespective of BCL2 status and is associated with tumor cell growth

“…Formalin-fixed paraffin-embedded tissue sections (3 µm thick) were immunohistochemically stained using a BOND-MAX autostainer (Leica Biosystems, Melbourne, Australia), with immune complexes visualized by the polymer method, according to the manufacturer's protocol and as previously described (10). The following primary antibodies were used: Rabbit anti-human PCDHGA3 (1:50; cat.…”

Clinicopathological analysis of 17 primary cutaneous T‐cell lymphoma of the γδ phenotype from Japan

“…Primary monoclonal antibodies raised against the human TCRβ (βF1; TCR1151, 8A3, 1:50 [Thermo Scientific, Waltham, MA, USA]) and TCR-γ chain constant region (TCR1153, γ3.20, 1:80 [Thermo Scientific]) were used to detect the αβ and γδ TCR, respectively. ( 12 ) In situ hybridization with Epstein–Barr virus (EBV)-encoded small RNA (EBER) probes (INFORM EBER; Leica Biosystems) was used to detect EBV.…”