Approaches to Treatment of Unifocal Langerhans Cell Histiocytosis

Abstract
Background: Langerhans cell histiocytosis (LCH) is a variable disorder involving either single bone or multiorgan systems. The most effective treatment of unifocal osseous lesions is debated in the literature. This study describes the treatment approaches for LCH and demonstrates the effectiveness of biopsy in providing symptom resolution. Methods: Records of 61 patients diagnosed with LCH at a single institution over an 11-year period were reviewed. Thirty-nine patients with biopsy-confirmed diagnoses of unifocal osseous LCH were included in the analysis. At this institution, lesions are surgically treated by incisional biopsy, trocar biopsy, or curettage and grafting. Patients receive chemotherapy on a case-by-case basis, depending on the lesion location and size. A Kaplan-Meier analysis was used to compare time with symptom resolution across treatment groups. Results: In the 39 patients with unifocal osseous LCH, treatment approaches included incisional biopsy (n=18, 46.15%), trocar biopsy (n=8, 20.51%), incisional biopsy and chemotherapy (n=8, 20.51%), and biopsy with bone grafting (n=5, 12.82%). The median time from biopsy to symptom resolution was 5.43 weeks, with an average length of follow-up of 1.59 years. The median time to symptom resolution was 3.86 weeks with incisional biopsy, 5.43 weeks with biopsy and grafting, 5.64 weeks with trocar biopsy, and 16.57 weeks with biopsy and chemotherapy. Overall, there was a significant difference (P=0.0262) in the time to symptom resolution across the different treatment approaches. Time to symptom resolution was significantly different between incisional biopsy and chemotherapy treatment compared with the incisional biopsy treatment (P=0.0027), as well as biopsy with grafting treatment (P=0.0264). Conclusions: Symptom resolution occurred rapidly after biopsy and did not significantly differ among patients who received incisional biopsy, trocar biopsy, or biopsy with grafting. Unifocal osseous LCH likely does not require aggressive surgical or medical management. Biopsy alone both confirms the diagnosis and precedes a predictable resolution of symptoms. Level of Evidence: Level III, retrospective comparative therapeutic study.