Eosinophilic granuloma in the anterior mandible mimicking radicular cyst
In May 2008, a 39-year-old man visited Wonkwang Dental Hospital in the city of Daejeon with pain in the anterior region of the mandible originating several months earlier. Intraoral examination revealed a slight gingival swelling and mobility of the mandibular anterior teeth. The past history of the patient was not contributory. There was no cervical or axillary lymphadenopathy. A panoramic radiograph showed an ovoid shaped, unilocular radiolucent lesion with a well-defined margin in the alveolar bone from the left lower lateral incisor to the right lower canine, with involvement of the apices of the mandibular incisors (). An intraoral radiograph revealed that the border of the lesion was non-corticated with beveled edges. The distal part of the right lower lateral incisor showed a typical floating tooth appearance. However, there was no tooth displacement and no root resorption (). The patient underwent root canal treatments of the mandibular left central incisor and right canine for his dental pain (). However, the pain did not subside, and the patient was referred to our department. We suspected an aggressive lesion rather than a cystic lesion due to the non-corticated border and floating tooth appearance. A biopsy of the mandibular anterior lesion was performed, and the patient was diagnosed with eosinophilic granuloma.\nAbout one month later, Cone beam Computed Tomography (CBCT), magnetic resonance (MR) imaging, and whole body bone scintigraphy with a Tc-99m MDP were performed at the dental hospital of Wonkwang University and the medical hospital of Eulgi University in the city of Daejeon. An axial CT showed destruction of the buccal and lingual cortex and a focal bony destructive lesion in the anterior mandible (). An MR image showed a focal high signal intense lesion in the left femur trochanter with adjacent bone marrow edema (). Bone scintigraphy revealed that there was no uptake of radiotracer in the trochanteric portion of the left femur on the initial study (); however, a new active bone lesion showing increased radiotracer uptake with a central photopenic finding in the left femur was detected in a one year follow-up study (). A biopsy specimen from the left femur was also taken, and the result showed the same lesion, eosinophilic granuloma. Another examination and laboratory tests, consisting of blood and serum biochemical studies, were within normal ranges. The treatment of the femur was carried out by surgical curettage.\nTwo years later, the patient revisited our dental hospital for the treatment of eosinophilic granuloma in the anterior mandible. A panoramic radiograph showed a slight increase in the size of the lesion in the anterior part of the mandible () compared with radiographs at the initial visit. The lesion was found to extend from the left lower first premolar to the right lower canine. Alveolar bone resection of the lesion was performed for complete removal of the lesion, and a biopsy specimen was taken.\nMicroscopically, the hematoxylin-eosin stained sample showed numerous Langerhans cells, eosinophils, and small lymphocytes. Immunohistochemically, these cells showed positivity for S-100 protein and CD1a protein (). Based on the clinical, radiological, and histopathological findings, the final diagnosis was an eosinophilic granuloma in the mandible and femur. The patient was periodically recalled for a follow-up check.