Langerhans cell histiocytosis in an adult: good response of cutaneous lesions to acitretin J. C. Cardoso, M. Cravo, R. Cardoso, M. M. Brites, J. P. Reis, O. Tellechea, C. Eloy* and A. Figueiredo Dermatology Department, University Hospital of Coimbra, Coimbra, Portugal; and *Pathology Department, Hospital Sa ˜o Joa ˜o, Porto, Portugal doi:10.1111/j.1365-2230.2010.03784.x Summary A 57-year-old man presented with a 2-year history of bilateral erosive lesions on the inguinal region, and erythematous, brown and crusted papules over the trunk. Histological examination of one lesion in conjunction with immunohistochemical study and electron microscopy led to the diagnosis of Langerhans’ cell histiocytosis. After a thorough examination, the only associated findings were retroperitoneal fibrosis and hypergonadotrophic hypogonadism with a granulomatous testicular infiltrate. The patient was treated with oral acitretin for 1 year (with a topical corticosteroid for the inguinal lesions), resulting in clearing of the cutaneous lesions. He underwent placement of bilateral double-J ureteral catheters and was started on hormone replacement therapy. At follow-up 1 year after treatment with acitretin ceased, the patient remained free of cutaneous lesions and his overall condition, including the retroperitoneal fibrosis, had improved. This case had an uncommon combination of features, with a good response to acitretin. Langerhans cell histiocytosis (LCH) encompasses a spectrum of syndromes with varied presentations, characterized by infiltration of tissues by Langerhans cells. It most likely results from neoplastic proliferation, although some authors support the hypothesis of a reactive process. 1,2 It is a rare condition, presenting most commonly in children, but occurrence in adult and elderly patients is well documented. 2,3 Treatment options are not standardized, with many anecdotal reports of success with several different therapeutic approaches. We describe a case of adult LCH, with some unusual features and a good response to a relatively new treatment, acitretin. Report A 57-year-old man presented with a 2-year history of asymptomatic erosive lesions on the inguinal regions and a papulous scaly rash on the trunk. He denied any systemic symptoms. His only regular medication was diclofenac for hip osteoarthritis, and he denied having taken other drugs recently. He did not smoke or have excessive alcohol intake. There was no relevant family history. On physical examination, bilateral, symmetrical, well- demarcated plaques were seen on the inguinal region with superficial erosions, some of them linear (Fig. 1a). On the trunk, multiple erythematous brownish papules, around 3–5 mm in size, with erosive or scaly crusted surfaces, were distributed mainly over the anterior chest, abdomen and lumbar region (Fig. 1b). There was no palpable lymphadenopathy or organomegaly. A biopsy disclosed a dense band-like infiltrate on the superficial dermis mainly composed of histiocytic cells, with abundant eosinophilic cytoplasm and large kidney- shaped nuclei, mixed with other cells, predominantly lymphocytes (Fig. 2a). Using immunohistochemistry, the predominant population was found to be positive Correspondence: Dr Jose ´ Carlos Cardoso, Servic ¸ o de Dermatologia, Hos- pitais da Universidade de Coimbra, Praceta Mota Pinto, 3000-075, Coimbra, Portugal E-mail: ze_carlos_cardoso@yahoo.com.br Conflict of interest: none declared. Accepted for publication 23 November 2009 Clinical dermatology • Concise report CED Clinical and Experimental Dermatology Ó 2010 The Author(s) Journal compilation Ó 2010 British Association of Dermatologists • Clinical and Experimental Dermatology, 35, 627–630 627