Head and Neck Langerhans Cell Histiocytosis in Children

Abstract Langerhans Cell Histiocytosis (LCH) is a sporadic myeloid neoplasm with proliferation of dendritic cells.1 In the United States, LCH has an estimated annual incidence of approximately 1 per million children.2 Controversy exists regarding management of LCH in head and neck: debridement, chemotherapy, or both. Few reports describe LCH in the OMS literature. The purpose of this study was to present experience with LCH of head and neck in children. This was a retrospective review of children with LCH at Children's Healthcare of Atlanta from 2009 to 2020. A patient was included when he or she: 1) was 18 years old or younger, 2) had LCH in the head and neck, and 3) had complete medical records. Medical records were reviewed for demographic information, lesion characteristics, and clinical presentations. Radiographic images were reviewed for specific findings characteristic of LCH (e.g., osteolytic changes, lymphadenopathy). Treatment regimen (debridement, debridement with chemotherapy, or chemotherapy only) and length of follow-up were recorded. The outcome variable was disease reactivation defined as: 1) a new LCH lesion or 2) an increase in size/recurrence of a lesion after treatment. Data were collected using a standardized collection form. Descriptive statistics were calculated. Overall, 67 patients (42 males) with a mean age of 6.5 years old met inclusion criteria. According to clinical, radiographic, and histological features, there were 3 presentations of LCH in the head and neck: 1) lesions in 1 system without CNS risk (i.e., single system without CNS risk, SS-), 2) lesions in 1 system with CNS risk (i.e., single system with CNS risk, SS+), or 3) multisystem (> 2 systems, MS) presentations. As a group, length of follow-up was on average 3 years (3 months-10.5 years). There were 24 patients (17 males) with an average age of 10 years old (19 months to 18 years) with SS- LCH. Lesions appeared as persistent local swelling (n = 18, 75%) and/or pain (n = 8, 33.3%). Lesions were predominately located in calvaria (n = 15, 62.5%) and mandible (n = 7, 29.2%). Radiographically, most patients had osteolytic changes (n = 18, 78.3%). Patients were treated via debridement (n = 16, 72.7%), chemotherapy (n = 5, 22.7%), or debridement with chemotherapy (n = 2, 9.1%). Three patients (12.5%) experienced reactivation. There were 30 patients (18 males) with an average age of 6 years old (9 month to 15 years) with SS+ LCH. Patients presented with persistent local swelling (n = 21, 70%), recurrent ear infection (n = 5, 16.7%), localized pain (n = 4, 13.3%), or systemic symptoms (n = 2, 6.5%). Radiographic findings were osteolytic changes (n = 24, 77.4%) and/or soft-tissue mass (15, 48.4%). All except 2 patients completed treatment consist of debridement (n = 1, 3.3%), chemotherapy (n = 17, 56.7%), or debridement with chemotherapy (n = 11, 36.7%). One patient (3.3%) who was treated with chemotherapy had disease reactivation. Thirteen patients (9 males) with an average age of 2 years old (1 day to 7 years) had MS LCH. LCH was found in skin (n = 9, 69.2%), lymphatic system (n = 6, 46.2%), and at least 1 bone (range 1-5). In this group, patients presented with extracranial visceral organ involvement on imaging (e.g., hepatosplenomegaly, pulmonary nodules). Patients were treated with chemotherapy (n = 12, 92.3%) or debridement with chemotherapy (n = 1, 7.7%). Six patients (40%) experienced reactivation, and 1 patient passed away during treatment. There are 3 separate categories of LCH in the head and neck. Oral and maxillofacial surgeons who provide care to children would benefit from approaching head and neck LCH based on these categories. A referral to hematology/oncology is necessary for appropriate diagnosis and management.