Orbital Lymphoma Presenting As Recurrent Orbital Cellulitis: A Diagnostic Challenge.

Orbital cellulitis is an infection of the orbital tissue behind the orbital septum. We report a case of a 71-year-old Malay lady, a passive smoker for 20 years, presenting with recurrent orbital cellulitis at the same site. She initially presented with right periorbital swelling, redness, and reduced vision worsening over two weeks, along with a firm swelling over the right temple. CT of the brain and orbit revealed a homogenous mass extending from the right sphenoid bone to the right orbit. The initial diagnosis was right sphenoid meningioma or metastasis. Her symptoms improved after 10 days of intravenous cefuroxime, prescribed for catheter-related phlebitis over her right hand, which developed during the admission. A follow-up MRI of the brain and orbit showed osteomyelitis changes in the right orbit and sphenoid bone. Histopathology revealed chronic inflammation without malignancy, and cultures were negative. The diagnosis was revised to right orbital cellulitis secondary to cranial osteomyelitis. The patient was lost to follow-up but returned three months later with recurrent symptoms, including right periorbital swelling, reduced vision, ophthalmoplegia, and right forehead swelling. She was treated with intravenous ceftriaxone, which resulted in partial symptom resolution. Neurosurgery planned a right craniotomy, but she was undecided and again lost to follow-up due to deteriorating health. Over time, her condition worsened, leading to readmission. A repeated CT scan of the brain and orbit showed a lobulated, enhancing soft tissue lesion in the right periorbital area with intralesional calcification and bony erosion. A biopsy confirmed it as high-grade B-cell lymphoma. The patient succumbed to the illness a few weeks later. This case highlights that orbital lymphoma can manifest as orbital cellulitis. Failure to respond to conventional orbital cellulitis treatment should raise suspicion of a more serious underlying cause. We advocate that clinicians consider orbital lymphoma as a potential diagnosis in elderly patients presenting with recurrent, culture-negative orbital cellulitis.