Abstract

Langerhans cell histiocytosis (LCH) is a heterogeneous group of idiopathic disorders with significant clinical overlap and is therefore classified based on the number of organ systems involved (e.g., single-system or multisystem LCH). Multisystem LCH is rare and typically presents in children with limited cases described in adults. We present a case of a 70-year-old woman with a history of hypertension and central diabetes insipidus who presented with several small asymptomatic smooth monomorphic pink to violaceous papules on the central chest, abdomen, and back followed by a rapid onset of generalized fatigue, weakness, and weight loss. Laboratory work up revealed progressive anemia, thrombocytopenia, and transaminitis. Radiographic work up was notable for hypophysitis, hepatomegaly, but no skeletal abnormalities. A punch biopsy of the central chest revealed a moderately dense band-like interstitial lymphohistiocytic infiltrate in the papillary dermis with exocytosis of histiocytes into the epidermis. CD1a and S100 stains confirmed an increased density of Langerhans cells. Bone marrow and liver biopsies showed a hypercellular bone marrow with maturing trilineage hematopoiesis and secondary sclerosing cholangitis, respectively; but no definitive evidence of a Langerhans cell infiltrate. However, somatic mutational analysis performed on the skin biopsy revealed a BRAF V600E mutation. In the setting of clinical and radiographic evidence of multiorgan failure, Langerhans cell hyperplasia in the skin with a concomitant BRAF V600E mutation is highly suggestive of multisystem LCH. With a variable spectrum of presentation and a paucity of reported cases in the literature, our report adds to the current literature of adult onset multisystem LCH.

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