Natural killer/T-cell lymphoma masquerading as orbital cellulitis.

We describe 3 cases of natural killer/T-cell lymphoma that presented by masquerading as orbital cellulitis. All of the patients were examined for pain, fever, proptosis, and motility restriction. Computed tomography of the orbits and sinuses revealed orbital soft-tissue swelling without focal abscess in all 3 cases. Bacterial and fungal cultures were negative in each case and all of the patients had initial improvement on systemic antibiotics, only to relapse several days later. Diagnosis of natural killer/T-cell lymphoma was then made based on biopsy of the orbit or sinus. Natural killer/T-cell lymphoma should be considered in cases of orbital cellulitis or sinusitis that fail to respond to traditional management. Biopsy of the affected region should be performed expeditiously to diagnose this condition. Repeat biopsy may be needed.