Fig. 3: Representative case of PTCL-TBX21 subtype (DL15, A–H).

A H&E stain shows diffuse proliferation of atypical large lymphocytes with abundant cytoplasm. The neoplastic cells were positive for CD2 (B) and TCRβF1 (C) and negative for CD4 (D) and CD8 (E). They showed an activated cytotoxic phenotype with expression of granzyme B (F). In addition, the atypical cells were positive for CXCR3 (G) and heterogeneously expressed pSTAT3 (H) in the absence of STAT3 gene mutations. Stains original magnification, ×400, H&E hematoxylin and eosin.