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.