A Survey on Orbital Space-Occupying Lesions during a Twelve-Year Period from a Referral Center in Iran

In this study, we describe different orbital space-occupying lesions (SOLs) from a referral center in Iran. In this retrospective case series, all records of "orbital tumors" with a definite histopathologic diagnosis at a referral center in Iran were reviewed from April 2008 to May 2020. A total of 375 orbital SOLs were included. The study population consisted of 212 (56.5%) female and 163 (43.5%) male subjects with overall mean age of 31.09 21.80 years. The most common clinical presentation was proptosis and the superotemporal quadrant was the most frequent site of involvement. Extraconal lesions (276 cases, 73.6%) outnumbered intraconal lesions (99 cases 26.4%). The great majority of SOLs (344, 91.7%) were primary, while 24 (6.4%) were secondary and 7 (1.9%) were metastatic. Benign lesions (309, 82.4%) were much more common than malignant SOLs (66, 17.6%). Overall, dermoid cysts and malignant lymphoma were the most prevalent benign and malignant orbital SOLs, respectively. The malignant to benign lesion ratio was 0.46 in children ( 18 years), 0.81 in middle-aged subjects (19-59 years), and 5.9 in older ( 60 years) cases. The most common type of malignancy was rhabdomyosarcoma in children, lymphoma in middle-aged subjects, and invasive basal cell carcinoma in older age group. Over the 12-year study period, benign, primary, extraconal orbital SOLs were more frequent than malignant, secondary, and intraconal lesions. The ratio of malignant lesions increased with age in this cohort of patients.