Rapid response of aggressive cranial Langerhans cell histiocytosis to combined intralesional and perilesional triamcinolone injection: a case report with video.

Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm that predominantly affects bone in the pediatric population, with the skull being one of the most frequent sites of involvement. Local complications following diagnostic procedures in this context are exceptionally rare and poorly described. We report the case of a 14-year-old male with unifocal cranial LCH who developed aggressive local progression after a diagnostic biopsy, characterized by progressive bone destruction, soft tissue involvement, surgical wound dehiscence, and exposure of tumor tissue. Given the rapid evolution of the lesion and the limitations for conventional surgical management, intralesional and perilesional triamcinolone infiltration (40 mg) was performed. A prompt clinical response was observed, with a significant reduction in lesion volume within 4 days. Follow-up magnetic resonance imaging at that time demonstrated a 50-70% decrease in the soft tissue component. During subsequent follow-up, progressive skin healing and early signs of bone repair were noted. This case highlights an uncommon local complication following biopsy of pediatric cranial LCH and suggests that local corticosteroid infiltration may represent a minimally invasive and potentially useful therapeutic alternative in selected cases with aggressive local progression and limited surgical options.