Metastatic Neuroblastoma to the Mandible of Children: Report of Two Cases and Critical Review of the Literature.

Neuroblastoma is the most common extracranial solid cancer of infancy, occurring mainly in the adrenal gland, with high metastatic potential. However, involvement of the head and neck region is rare. Here, we present two cases of metastatic neuroblastoma of childhood, in which a mandibular swelling was the first sign of disseminated disease. Case 1 describes a 4-year-old boy with a 2-week history of painful swelling in the left mandibular region, body soreness and weakness. Panoramic radiography and computed tomography showed a destructive lesion in the left mandibular ramus. Case 2 describes a 3-year-old boy with a 1-month history of swelling in the right mandibular area. Panoramic radiograph and cone-beam computed tomography showed a destructive lesion in the right body and ramus of the mandible, displacing tooth germs, with the destruction of vestibular and lingual bone cortices. In both cases, microscopic analyses revealed a diffuse proliferation of small, round, and blue cells with hyperchromatic nuclei and scant cytoplasm. While Case 1 was more undifferentiated, Case 2 presented eosinophilic areas suggestive of neuropil. A large immunohistochemical panel was performed, showing expression of neural markers such as CD56, neuron-specific enolase (in Case 2), chromogranin, and synaptophysin. Both lesions presented a high proliferation index (Ki67 > 70% and 80%, respectively). Positron emission tomography-computed tomography revealed ipsilateral adrenal primary lesions in both cases, with multiple bone metastatic lesions. Besides the mandible, multiple sites of the axial and appendicular skeleton were affected. Treatment consisted of induction chemotherapy, adrenalectomy, consolidation chemoradiotherapy, and post-consolidation therapy.