To report a case of primary peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), of the eyelid.

A 48-year-old healthy male patient presented with a mass on the upper lid of 2 months in duration. The lesion was reddish, well-demarcated, oval shaped, and measured approximately 8 × 4 mm. The mass did not respond to incisional drainage and intra-lesional triamcinolone. An excisional biopsy for diagnosis was performed.

On microscopic examination, a localized dense lymphocytic infiltration was observed in the subepithelial area, and cytologic atypia was observed under high power. On immunohistochemical examination, tumor cells were positive for CD3 but negative for CD20, CD30, CD56, ĸ-light chain immunoglobulin, λ-light chain immunoglobulin, and increased Ki-67 activity was noted. A histopathological diagnosis of PTCL-NOS was made.

PTCL-NOS, which rarely occurs on the eyelids, commonly accompanies generalized lymphadenopathy and "B symptoms" such as fever and weight loss. Herein, the authors report a case of PTCL-NOS of the eyelid presenting as a rapidly growing solid mass in an otherwise healthy patient.