Ocular Adnexal Natural Killer- and T-cell Lymphomas: A Review

Natural Killer- (NK) and T-cell lymphomas presenting in the ocular adnexa are rare. They account for ~3% of all ocular adnexal lymphomas and 17% of eyelid lymphomas. This article presents the epidemiology, clinics, treatment, and prognosis of ocular adnexal NK- and T-cell lymphomas. Orbital involvement is the most common in systemic NK- and T-cell lymphomas, including extranodal NK/T-cell lymphoma (ENKTL), systemic anaplastic large cell lymphoma (sALCL), and peripheral T-cell lymphoma (not otherwise specified) (PTCL-NOS). Primary cutaneous T-cell lymphomas, including mycosis fungoides (MF) and primary cutaneous anaplastic large cell lymphoma (C-ALCL), may present in the eyelids or periorbital skin. Several of the NK- and T-cell lymphomas, including ENKTL, sALCL, C-ALCL, PTCL-NOS, and MF, show a male predilection and present in adults. However, some subtypes including T-lymphoblastic leukemia/lymphoma are frequent in adolescents and young adults. Systemic ocular adnexal NK- and T-cell lymphomas often mimic inflammatory orbital conditions. Early biopsies, even in younger patients are therefore important to not miss these rare malignancies, which often have advanced stage disease and a poor prognosis. Primary cutaneous lymphomas can present with erythematous patches or as ulcerated eyelid tumors. In general, cutaneous lymphomas have a better prognosis, although recurrences may occur, leading to increased patient morbidity. The treatment for systemic NK- and T-cell lymphomas includes chemotherapy regimens depending on the lymphoma subtype, combined with ocular adnexal radiotherapy, and in some cases hematological stem-cell transplantation. Primary cutaneous lymphomas are frequently treated with radiotherapy, skin-directed therapies, and in some advanced cases with systemic treatments.