An unusual presentation of langerhans cell histiocytosis: perianal lesion

Objective – Langerhans cell histiocytosis is a rare disease characterized by monoclonal proliferation and infiltration of organs by large mononuclear cells. Here we report a case of Langerhans cell histiocytosis with non-classic perianal presentation and diabetes insipidus. Case report – A 10-year-old male patient diagnosed with central diabetes insipidus was referred to us with the complaints of abdominal pain, bloody stool, and an irregular ulceration on the bilateral perianal region. With the suspicion of inflammatory bowel disease the patient underwent colonoscopy and the result was normal. Due to the prior diagnosis of central diabetes insipidus the lesion was thought to be histiocytosis. A biopsy was performed and histological findings were consistent with Langerhans cell histiocytosis. Conclusion – Perianal involvement is an unusual presentation for Langerhans cell histiocytosis. In the case of suspicion of nonspecific ulceration of this area, the precise diagnosis should be made by histological means.