TCLs. (A) ALK⁻ ALCL with DUSP22 rearrangement. There is a relatively monotonous proliferation of large transformed cells and classic “Hallmark” cells. (B) Breast implant–associated ALCL. The seroma cavity demonstrates numerous very large anaplastic-appearing lymphoid cells. (C-D) Primary cutaneous acral CD8⁺ TCL. (C) Nodule on the ear. (D) There is a diffuse monotonous infiltrate of CD8⁺ T cells. (E) EATL. The somewhat pleomorphic intestinal infiltrate extends into the epithelium and would be associated with enteropathic changes elsewhere in the intestine. (F) MEITL. The monotonous intestinal infiltrate is very epitheliotropic. (G-H) Primary cutaneous CD4⁺ small/medium T-cell LPD. (G) Small nodule on scalp. (H) Although the infiltrate is dense and lymphoma-like, this is now to be considered a lymphoproliferative disorder rather than a “lymphoma.” (A,E,F,H) Hematoxylin and eosin stain; (B) Romanowsky-type stain; (D) CD8 immunoperoxidase stain.