Langerhans Cell Histiocytosis Mimicking a Meningeal Lesion with Temporal Bone and Muscle Compromise in an Adult Patient: A Case Report.

Introduction  Langerhans cell histiocytosis (LCH) is a rare proliferative systemic disease characterized by the growth of abnormal dendritic cells and wide-ranging organ involvement. This condition can affect individuals of all ages, but most commonly children, with a peak incidence in toddlers. Symptoms may vary depending on the affected organ or system. Case Report  A 43-year-old man presented with a left temporal stabbing headache unresponsive to management with therapy and nonsteroidal anti-inflammatory drugs. Initial evaluation revealed a contrast-enhanced left temporal extra-axial lesion with bone and muscle compromise. Differential diagnoses, including multiple myeloma, were explored. Initial laboratory tests and imaging studies showed no other abnormalities, except for splenomegaly and a residual granuloma in the left lung. En bloc resection of the lesion was recommended. The patient underwent surgical intervention, which included resection of the dural lesion and all borders of an infiltrating tumor within the temporalis muscle and the affected portion of the left temporal bone. Posterior pathological examination revealed LCH. Postoperative course was uneventful. Follow-up appointments were scheduled after pathology results confirmed the diagnosis. Patient has continued follow-up for the following 3 months after the surgical procedure. Further evaluations are pending. Discussion  This case report corresponds to a patient with LCH. These patients are individualized and stratified based on local or systemic involvement to determine the most appropriate type of management. This is a rare case as LCH is rare in older patients and the initial presented lesion initially mimicked a meningioma; however, its atypical behavior and associated lytic compromise led to consideration of possible differential diagnoses. Conclusion  LCH can present with lytic bone lesions, mimicking other conditions, including infiltrative neoplastic lesions. Early diagnosis and appropriate surgical management are essential for optimal patient outcomes. Long-term follow-up is crucial to monitor disease progression and response to treatment.