Histiocytic lesions of the orbit: A study of 9 cases.

PURPOSE: To describe the clinical presentation, treatment, and outcome of patients with histiocytic lesions of the orbit.

METHODS: Retrospective study of 9 patients treated and followed up between October 2001 and January 2018.

RESULTS: Eight patients in our series were males and one patient was female. The mean age at presentation was 16.8 years (range, 1 to 42 years). All patients had unilateral disease. The most common presenting complaint was upper eyelid swelling in 8 of 9. All patients underwent preoperative computed tomography (CT) and magnetic resonance imaging (MRI). Eight of 9 patients demonstrated orbital bone erosion with adjacent soft tissue mass. Destruction of the orbital roof and contrast enhancement of dura were detected in 3 cases. All cases underwent orbitotomy and subtotal tumor excision with additional bone curettage (4 cases) and intraorbital steroid (40 mg triamcinolone acetonide) injection (3 cases). Adjuvant systemic chemotherapy consisting of vinblastine and prednisone was administered in 3 cases with dural involvement. External radiotherapy (1000 cGy) was applied in one case because of widespread disease. Histopathologic diagnoses were eosinophilic granuloma (7 cases), necrotic xanthogranuloma (1 case), and Langerhans cell sarcoma (1 case). The mean follow-up period after diagnosis was 19.7 months (range, 1-96 months). There was no systemic or multifocal bone involvement in eosinophilic granuloma cases at initial presentation and follow-up. None of these patients developed diabetes insipidus or neurologic symptoms. The patient with Langerhans cell sarcoma died from systemic disease 1 month after diagnosis of the orbital tumor. The patient with necrotic xanthogranuloma did not develop any malignancy at 9 months follow-up.

CONCLUSIONS: Eosinophilic granuloma was the most frequently encountered orbital histiocytic lesion in our series. Eosiophilic granuloma usually responded well to subtotal tumor excision, bone curettage, and intraorbital corticosteroid injections. Systemic chemotherapy was used in cases with full thickness bone destruction and adjacent dural enhancement in an effort to prevent the development of central nervous system disease.