Surgery / surgery odontogenic tumors

Conventional (Solid and Multicystic) Ameloblastomas

These are the most common type. They are usually radiolucent on radiography and clinically are partially or completely solid. Management is resection with a 1.5cm margin.

As both conventional Ameloblastoma and unicystic ameloblastoma have been found to harbor BRAFp.V600E mutations, aggressive and destructive tumours could be candidates for BRAF-targeted therapy that has the potential to reduce tumour size and ultimately enable a conservative surgical procedure. Preliminary data of biological treatment show effectiveness in selected cases.

BRAF is a human gene that encodes the B-Raf protein, which is responsible for cell proliferation. When the BRAF gene is mutated, it is constantly activated. This leads to uncontrolled cell proliferation (independent of any external stimulus), a condition that may result in the generation of tumors. Somatic oncogenic mutations in the BRAF gene (specifically the BRAF-V600E mutation) occur in more than 60% of mandibular ameloblastomas.

This is a big breakthrough, which is a genetically based patient specific treatment, to ameloblastoma. In the cases treated, the BRAF inhibitor resulted in substantial tumor regression, allowing for non-mutilating complete surgical removal, bone regeneration and organ preservation.

Peripheral /ExtraosseousAmeloblastoma

These have a good prognosis, arise from the gingivae rather than tooth and are most common in premolar area of mandible, then tuberosity of the maxilla. A radiograph should be taken to exclude a perforating intraosseous ameloblastoma. Management is conservative excision. Long term follow is required.

Malignant (Metastasising) Ameloblastoma and Ameloblastic Carcinoma

Ameloblastoma sometimes exhibit behavior of metastases that are most often found in the lungs. The diagnosis of malignant ameloblastoma should be made when a tumor in both primary and metastatic locations demonstrate histopathologic features of ameloblastoma. If surgically feasible, wide resection and reconstruction should be performed on the primary and metastatic lesions by a surgical team.

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Radiation and chemotherapy are questionable modalities for adjunctive treatment and should be reserved for palliation.

The diagnosis of ameloblastic carcinoma should be made when microscopic examination of ameloblastoma cases shows cytologic features of malignancy in the primary tumor. Ameloblastic carcinomas show local aggressive behavior but do not demonstrate the character of metastasis.

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