Recurrent Vision Fluctuations and Orbital Signs Unmasking T-Cell Lymphoma: A Case Report.

Introduction: Orbital T-cell lymphoma is a rare and diagnostically challenging malignancy that can closely mimic inflammatory conditions such as Tolosa-Hunt syndrome (THS), particularly due to overlapping clinical and radiological features. Case Presentation: We report the case of a 21-year-old male who initially fulfilled the ICHD-3 criteria for THS, demonstrating unilateral painful ophthalmoplegia and transient steroid responsiveness. However, recurrence of symptoms and subsequent histopathological evaluation confirmed the presence of extranodal orbital T-cell lymphoma. This case underscores the critical importance of maintaining a high index of suspicion for malignancy in steroid-responsive orbital syndromes, especially when atypical features or relapses occur. Early biopsy and multidisciplinary coordination enabled timely initiation of CHOEP chemotherapy, leading to slight clinical improvement. This report adds to the growing body of literature emphasizing the masquerade potential of lymphoid malignancies in orbital inflammation. Conclusion: Orbital T-cell lymphoma can mimic benign inflammatory conditions such as orbital cellulitis. Prompt biopsy and multidisciplinary evaluation are crucial for accurate diagnosis and timely initiation of appropriate treatment.