Figure Legend:
Figure 1: A skin biopsy of SPTCL with increased γδ T cells. A and B, the skin lesions show a spectrum of plaques, subcutaneous nodules and so on. The skin biopsy reveals an ulcerated lesion with extensive dermal and subcutaneous lymphoid infiltrate (C, H&E, 20x). Repeated PCR for T-cell gene rearrangements in multiple skin biopsies confirms a persistent clonal gene rearrangement (D). On high power, the H&E sections show a adipose rimming by atypical lymphocytes (E, H&E 200x and F, H&E, 400x). The atypical lymphocytes are predominantly CD3+ T cells (G, 200X), CD8+ (H, 200x) with high Ki67 proliferation rate (I, 200x). TCR delta stains a marked increase of atypical T lymphocytes (K, 200x), although TCR BF1 also highlights substantial T lymphocytes (L, 200X). CD79a, CD123 and EBER-ISH are mostly negative (not shown).
Figure 2: A skin biopsy of γδ variant of PLC. The H&E sections reveals parakeratosis, psoriasiform epidermal hyperplasia with minimal spongiosis but exuberant lymphocyte exocytosis multifocally tagging along the dermoepidermal junction and forming small clusters (A, H&E, 200x; B, H&E, 400X) within the epidermis. The dermis features a mildly dense perivascular lymphohistiocytic infiltrate. Immunohistochemical stains reveal a population of CD3+ T lymphocytes (C, 200X) with very rare CD20+ B lymphocytes (not shown). CD5 (D, 200X) and CD7 (not shown) expressions are diminished compared to epidermal CD3 expression. CD4 (E, 200x) and CD8 (F, 200X) expression are decreased within the epidermis. TCR-Delta highlights an increase in γδ T cells (G, 200x). CD30 (H, 200x) is largely negative. Neither fungal microorganisms nor basement membrane changes are seen with interpretation of PAS histochemical stain (not shown). PCR for T-cell gene rearrangements were positive.