A-D, PTCL, NOS with TCR silent phenotype (Case 15). A) Monomorphic medium sized atypical lymphocytes with irregular nuclear contours, vesicular chromatin and occasional nucleoli. The neoplastic T-cells are CD8-positive (B), TIA-1-positive (C) and beta-F1 (D) negative. TCR gamma was also negative (not shown). E-H) TCR gamma positive cases (Case 13 and 14). The cells are mostly small-medium with irregular nuclear contours, admixed occasional larger cells and demonstrate prominent perivascular cuffing (E and G). The cells are strongly positive for TCR-gamma immunostain (F and H).