Langerhans cell histiocytosis of the female genital tract: a literature review

Abstract

Langerhans cell histiocytosis (LCH) is a rare malignant disease involving the accumulation of a monoclonal proliferation of cells in various organs, that phenotypically resemble Langerhans cells (LC). LCH is not merely a hyperplasia of LC, as it typically affects organs that are outside of their normal physiologic distribution. Normal Langerhans cells are bone marrow-derived dendritic cells that populate the epidermis and are distinguished by the presence of Birbeck granules and cell surface protein CD1a. LC act as sentinels; they recognize, internalize, and process antigens encountered in the skin. Upon encountering an antigen, LC become activated with subsequent maturation and induction of their migratory capacity. Langerhans cells in patients with LCH are aberrant and profoundly differ from normal LC. The clinical spectrum of LCH is quite diverse; multiple organs can be affected. "Pure" genital Langerhans cell histiocytosis is a rare presentation, with only 12 previously reported cases. Due to the rarity of this disease, treatment of genital LCH is still very diverse. No modality is proven to be superior in improving patient outcome, and relapses frequently occur after surgery. Dramatic responses of cutaneous and ano-genital lesions to thalidomide and interferons have been reported. We advocate the use of immuno-modulating agents in LCH of the female genital tract first, rather than surgery.