LCH is a rare disease with an incidence of 0.2–0.5 per 100,000 children per year [
6]. The disease involves typically patients aged from 5 to 15 years in approximately 90% of cases, with a slight male predominance [
6]. To the best of our knowledge, a bilateral localization of LCH on both forearms has not been reported. The most frequent site of EG is the skull followed by the femur, then the ribs. Localization in the forearm is approximately 1.5% [
7]. The most common complaint is the pain, often worse at night [
8]. However, a fracture, a swelling, a deformity, and a soft tissue component are also encountered. The lesions caused by LCH are often located on the diaphysis, the metaphysis, or extend to the physis and epiphysis of the long bone [
9]. Cortical thinning, intracortical tunneling, and medullar widening are often found on radiography. The periosteal reaction, while less common, may be present at an early phase of the disease, giving a more aggressive and pseudomalignant appearance [
9]. The most common lesions on MRI are perilesional bone marrow edema, periosteal reaction, endosteal scalloping, and postcontrast enhancement with or without soft tissue mass [
10]. The differential diagnoses include aneurysmal bone cyst, osteomyelitis, Ewing’s sarcoma, osteoblastoma, Gaucher’s disease, acute leukemia, and metastatic tumor [
11]. The diagnosis of EG is based on histological and histochemical identification. The therapeutic modalities include observation for spontaneous resolution, biopsy, curettage with or without bone grafting, local steroid injection, anti-inflammatory drugs, bisphosphonates, radiotherapy, chemotherapy, and immunotherapy [
6]. The results of treatment of solitary lesions are always satisfactory. In contrast, multifocal and multisystem types of LCH are generally treated with chemotherapy in combination with other therapeutic modalities [
5].