Abstract
Purpose: Ophthalmic histiocytic lesions comprise a heterogeneous rare group of disorders that are characterized by an abnormal proliferation of histiocytes and may affect all age groups of both genders. This rare group of diseases in the ophthalmic practice has not been previously studied in this area of the world and only individual cases reports were reported.Methods: This retrospective study has been approved on an expedited basis by the Human Ethics Committee/Institutional Review Board (HEC/IRB) at King Khaled Eye Specialist Hospital (KKESH) with a collaborative agreement between KKESH and King Abdulaziz University Hospital (KAUH) in Riyadh, Saudi Arabia aiming to collect all biopsied ocular and periocular histiocytic lesions from both centers from January 1993 to December 2018. The histopathological diagnosis was confirmed, and cases were re-classified by review of all histopathological slides. The corresponding demographic and clinical data were analyzed. Relevant literature review was also carried on for comparison of our collected analyzed data to published data and to draw our own conclusions.Results: A total of 34 ocular/periocular histiocytic lesions of 28 patients who were mostly Saudis (92.9%) were included. Male to female ratio was 4:3. The median age at presentation was 6.4 years (range: 2.8-35). Twenty-two patients had unilateral involvement and 6 patients had bilateral lesions. In Langerhans cell histiocytosis (LCH)=L group, the most common presenting findings were eyelid swelling (75%), periocular tenderness (37.5%), proptosis/globe displacement (37.5%) eyelid erythema (25%), and orbital pain (12.5%). In Rosai Dorfman disease (RDD)=C group, proptosis/globe displacement occurred in all patients, followed by decreased vision (80%). Patients with C group diseases had variable clinical features owing to the different locations of the histiocytic lesions with the majority involving the eyelids (66.7%). Diagnosis was accurately reached clinically in 38.8%, 33.7%, and 46.7% among patients in the L group, C group, and R group respectively. Overall, the clinical diagnosis was in concordance with the histopathologic diagnosis in 14 only out of 34 lesions (41.2%). Conclusions: We concluded that C group was the commonest histiocytic lesion encountered in about two-thirds of the lesions with particular prevalence of Juvenile xanthogranuloma (JXG). The histiocytic disease is more likely to be overlooked clinically especially in this group owing to its rarity and is diagnosed mainly with the help of histopathological and immunohistochemical studies. The median age of presentation was higher for R group patients, while there was tendency for JXG to present at a later age compared to the published reports. Intraocular involvement was extremely rare. All L group cases were strictly unilateral disease, while RDD (C group) was most commonly bilateral. Future research on the genetic aspects, management, and prognosis are necessary.