Langerhans cell histiocytosis of the hard palate in an infant

Langerhans cell histiocytosis (LCH) is a rare disorder that is characterized by the abnormal proliferation of bone marrow-derived Langerhans cells. In patients with LCH, these cells multiply excessively and build up in certain areas of the body, causing tumors called granulomas. LCH can occur in various organs, wherein it causes tissue destruction, and is classified based on its occurrence in single or multiple organ systems in addition to single or multiple sites within a particular organ. Multiple-organ type LCH can cause patient death, and therefore, needs systematic chemotherapy with various anticancer drugs. The annual incidence rate of LCH is 5 cases per million, with more than 50% of cases affecting individuals under the age of 15 years. Moreover, although it mostly occurs in the mandible or oral and maxillofacial regions, three cases of hard palate LCH have been reported so far in children under the age of 2 years. We herein report a case of single-organ type LCH of the hard palate in an infant. A 4-month-old boy was referred to our hospital following the detection of a palatal mass. The mass was hard, elastic, elevated, dark red, 10 mm in diameter, and located slightly to the right of the midline of the palate. When the patient was 10 months old, total resection was performed under general anesthesia. The hisiocyte-like cells exhibited strong immunoexpression for CD1a and S100 protein positivity, confirming the diagnosis of LCH.