Clinical spectrum and management outcomes of Langerhans cell histiocytosis of the orbit.

Purpose: To describe the clinical spectrum and management outcomes of Langerhans cell histiocytosis (LCH) involving the orbit. Methods: Retrospective review of patients with orbital LCH presenting at the Sankara Nethralaya, Chennai, India, over the past 15 years. Demographic details, presenting features, radiology, histopathology, immunohistochemistry, and management outcomes were analyzed. Results: Nine patients were reviewed. The mean age of presentation was 10.12 ± 14.31 years (range: 6 weeks to 35 years). Eyelid swelling was the most common presenting feature (4, 44.4%), followed by proptosis (3, 33.3%). The mean duration of the presentation was 2.21 ± 2.77 months. Radiological investigations revealed orbital roof osteolytic defects in six (66.6%) patients. Six patients underwent near-complete excision of the mass while three underwent incisional biopsy. Histopathology revealed histiocytes with nuclear grooving and numerous eosinophils characteristic of LCH. The cells were positive for CD1a and S 100 antigens. None of the patients had any systemic involvement. Three received systemic steroids and four received systemic chemotherapy. At a mean follow-up of 17.85 ± 23.46 months, all had complete remission without any signs of recurrence. One patient was lost to follow-up after near-complete excision while one adult patient with a mass in the intraconal space had no recurrence after near-complete excision. Conclusion: LCH is a rare disorder of the orbit that commonly occurs in children and should be considered a differential for osteolytic lesions involving the orbit. All patients should undergo a systemic evaluation to rule out multifocal disease. The treatment depends upon disease extent and risk factors.