Ophthalmic histiocytic lesions: a baseline demographic and clinicopathological study of 28 cases from two eye centers.

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 sexes. The aim of this study was to highlight the basic demographic, clinical, and histopathological characteristics of this rare group of diseases in ophthalmic practice, which has not been previously studied in this area. Only individual cases have been previously reported.

Methods: This was a retrospective study of all biopsied ocular and periocular histiocytic lesions from two centers, King Khaled Eye Specialist Hospital (KKESH) and King Abdulaziz University Hospital (KAUH) in Riyadh, Saudi Arabia, from January 1993 to December 2018. The histopathological diagnosis was confirmed, and the cases were re-classified by reviewing all histopathological slides. The corresponding demographic and clinical data were analyzed. A relevant literature review was also carried out 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 in 28 patients who were mostly Saudis (92.9%) were included. The male-to-female ratio was 4:3. The median age at presentation was 6.4 years (range: 2.8-35 years). Twenty-two patients had unilateral involvement, and six patients had bilateral lesions. In patients with 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 patients with Rosai Dorfman disease (RDD; R group), proptosis/globe displacement occurred in all patients and 80% had decreased vision. Patients in the C group (Cutaneous non-LCH histiocytoses) had variable clinical features because of 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% of patients in the L, C, and R groups, respectively. Overall, the clinical diagnosis was in concordance with the histopathologic diagnosis in 14 out of 34 lesions (41.2%).

Conclusions: Histiocytic disease is more likely to be overlooked clinically owing to its rarity. In the C group, juvenile xanthogranuloma (JXG) was the most commonly encountered histiocytic lesion and had a tendency to present at a later age with extremely rare intraocular involvement in contrast to previously published reports. The median age at presentation was higher in group R. All patients in group L had strictly unilateral disease, while RDD (group R) was most commonly bilateral. Future research on genetic aspects, management, and prognosis is necessary.