To report a case of complete remission of primary orbital peripheral T-cell lymphoma with panniculitis-like features after chemotherapy.

A 57-year-old healthy female presented with periorbital swelling and symptoms of diplopia. The patient was first treated with high-dose systemic corticosteroids, however, symptoms persisted. Therefore, anterior orbitotomy with excisional biopsy was performed for diagnostic purposes. On microscopic examination, the excised mass showed localized dense lymphocyte infiltrates, and cytologic atypia was observed under a high-power field. On immunehistochemical examination, tumor cells were positive for CD3 and CD8 but negative for CD4, CD20 and CD56. Based on histopathological results, primary orbital peripheral T-cell lymphoma with panniculitis-like features was diagnosed. Additionally, molecular pathological testing was positive for Epstein-Barr virus. Subsequently, the patients underwent chemotherapy and complete remission was obtained.

Peripheral T-cell lymphoma often manifests as systemic symptoms, including lymph node enlargement and B symptom. The primary form of the disease in an orbit is very rare, and has a poor prognosis with a high mortality rate because the disease quickly progresses. Herein, the authors report a rare case of a healthy patient without any past medical history who achieved complete remission of a fast-growing primary orbital T-cell lymphoma with no preceding systemic symptoms.