Langerhans cell histiocytosis that improved with oral isotretinoin therapy

Abstract

Langerhans cell histiocytosis (LCH) is a reactive disease in which abnormal Langerhans cells accumulate in various body sites. We report here on a 51-year-old male patient with LCH that was classified as single-system disease (restricted LCH). The skin lesions were a small, deep ulcer in the right inguinal area and multiple erythematous papules scattered on the lower abdomen, and the patient had these lesions for 1 year. The histopathologic examination revealed a dense histiocytic infiltration in the dermis, and most of the cells showed the characteristics of LCH cells. The immunohistochemistry for S-100 protein and CD1a complex all showed positive results. The patient was much improved after surgical excision of the inguinal ulcer and administering oral isotretinoin (20 mg daily) for 8 months, and there was no recurrence. We think retinoid is an effective treatment option for LCH, especially for single system disease.