A Solitary Langerhans Cell Histiocytosis Lesion of the Scapula Mimicking Malignancy in a Child: A Case Report

Abstract

Background: Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disorder with heterogeneous clinical manifestations. Isolated bone involvement is the most common form, but a solitary lesion in the scapula is unusual and its imaging appearance can mimic a primary malignant bone tumor, posing a diagnostic challenge. This report aims to highlight this rare presentation to improve clinical recognition and management.
Case Report: A 12-year-old boy presented with a two-week history of left shoulder pain. Imaging revealed a solitary, expansile lytic lesion in the scapula with an associated soft tissue mass, initially raising suspicion for Ewing's sarcoma or osteosarcoma. A definitive diagnosis of LCH was confirmed via ultrasound-guided core needle biopsy and immunohistochemical analysis, which showed positivity for CD1a and Langerin (CD207). The patient underwent intralesional curettage and bone grafting and achieved a favorable outcome.
Conclusion: This case illustrates an unusual presentation of LCH as a solitary scapular lesion mimicking a bone sarcoma. It underscores the importance of considering LCH in the differential diagnosis of pediatric osteolytic lesions, even in uncommon locations. Awareness of this presentation can guide appropriate diagnostic biopsy and prevent misdiagnosis and unnecessary aggressive treatment.
Key words: Langerhans Cell Histiocytosis; Child; Scapula; Osteolytic Lesion; Ultrasound-Guided Biopsy; Differential Diagnosis