[Clinicopathologic observation of orbital natural killer-T cell lymphoma].

Objective: To investigate clinical manifestation, diagnosis and treatment of orbital natural killer (NK)-T cell lymphoma.

Methods: It was a retrospective case series. Seven orbital NK-T cell lymphoma patients confirmed by surgical biopsies were collected during the past 22 years. We reviewed the records, surgical and treatment procedures. Surgical specimens were studied with HE staining, immunohistochemical staining and molecular biological analysis.

Results: These patients had proptosis, eye motive inhibition or fixation and visual acuity was decreased or even without light perception. Skin of inner canthus and eyelids appeared red and swollen, with ulceration and cavity formation. CT scan revealed that the tumor showed uneven density and an unclear border. Tremendous lymphocyte infiltration and tissue necrosis in the tumor were observed in the biopsy tissue. LCA, CD45RO and CD57 immunohistochemical staining revealed positive results. Clonal T-cell-receptor gene rearrangements of two patients showed negative results and the Epstein-Barr virus was detected.

Conclusions: Orbital NK-T cell lymphoma is a rare disease. The characteristics of this disease include a highly aggressive clinical course, severe destruction and a poor prognosis. The final diagnosis depends on HE staining, immunohistochemical staining and molecular biological examination.