Eosinophilic granuloma: Case-report of spontaneous resolution

Eosinophilic granuloma (EG) is one of the forms of Langerhans cell histiocytosis (LCH) with a benign and self-limiting course that most commonly affects children and young adults. This case describes a 33-year-old woman who reported a history of pain localized in the left iliac and gluteal region for 3 months, which improved with the administration of nonsteroidal anti-inflammatory drugs (NSAIDs). Magnetic resonance imaging (MRI) revealed a solitary osteolytic lesion in the left iliac bone with associated bone edema that subsequently was bioptized. The report confirmed the diagnosis of EG with identification of Langerhans cells positive for S100 protein. A progressive spontaneous resolution over the course of 1 year after the biopsy was observed, without any intervention beyond symptomatic management. This case highlights a rare case of an eosinophilic granuloma (EG) in an adult woman evaluated with magnetic resonance imaging (MRI) technique, which was resolved spontaneously following the biopsy examination. We will discuss the clinical presentation, radiological findings and treatment.