Primary cutaneous γδ T-cell lymphoma, pathologic features. (A) Hematoxylin and eosin, 20x, zonal dermal and subcutaneous infiltrates of atypical and hyperchromatic cells. (B) Hematoxylin and eosin, 400x, interface changes with subtle dermal alteration suggestive of connective tissue damage by cytotoxic mediators. (C) Hematoxylin and eosin, 400x, lobular panniculitis composed of high-grade-appearing lymphocytic infiltrate, with absence of clear adipocyte rimming. (D) Immunohistochemistry for TCR delta chain with strong diffuse labeling. (E) Immunohistochemistry for TIA-1. (F) Immunohistochemistry for CD56 highlighting malignant cells. TCR, T-cell receptor; TIA, T-cell intracellular antigen.