Langerhans cell histiocytosis in the adult clavicle: A case report

INTRODUCTION: Langerhans` Cell Histiocytosis (LCH) is a rare disease involving proliferation of Langerhans-type cells, which shares immunophenotypic and ultrastructural similarities. In this article, we report a case of Langerhans cell histiocytosis in solitary involvement of clavicle of adult male. PRESENTATION OF CASE: A 21-year-old male visited outpatient department on account of solitary palpable tumorous lesion in right clavicle. The lesion was found 2 weeks before the visit, and it triggered pain but no tenderness. Findings on X-ray, and CT were suggestive of homogeneous osteolytic lesion of the clavicle, and hot uptake was found in right clavicle on bone scan which is commensurate with site of the lesion. Based on findings on MRI, Ewing's sarcoma, osteomyelitis and malignant hematologic malignancies were initially suspected for differential diagnosis. For the purpose of excision and histologic analysis, excisional biopsy was performed. Biopsy concluded with diagnosis of LCH. DISCUSSION: LCH is widely renowned for its frequent occurrence in pediatric ages, and it occurs usually between ages of one and four. It occasionally occurs in adults. LCH in skeletal system usually involves cranium, vertebrae, rib and so forth. It is very rare for LCH to occur exclusively in clavicle when it involves skeletal system. For diagnosis of LCH, sole imaging studies are inadequate, and histologic, immunochemical analyses are confirmative modalities. Treatment of LCH is not currently standardized. CONCLUSIONS: Most of the solitary tumorous lesions in clavicle in adults call for various differential diagnoses. LCH should be considered in the diagnosis of a adult patient with a clavicle mass.