Ameloblastoma

1. Classification

1.1. Follicular, plexiform, acanthomatous, basal cell type, desmoplastic, granular cell

1.2. Central and peripheral

2. Clinical features

2.1. Ameloblastoma grow slowly and usually are asymptomatic until a swelling is noticed. Most patients thus typically present with a complaint of swelling and facial asymmetry. Occasionally, small tumors may be identified on routine radiography. As the tumor enlarges, it forms a hard swelling and later may cause thinning of the cortical bone resulting in an egg shell crackling which can be elicited. The slow growth also allows for reactive bone formation leading to gross enlargement and distortion of the jaw. If the tumor is neglected, it may perforate the bone and spread into the soft tissues making excision extremely difficult.

2.2. Peripheral ameloblastoma usually presents as normal colored, smooth surfaced nodules or enlargements but occasional tumors may present with erythematous or papillary surface. They are slow growing and cause little or no bone erosion. Any saucerisation of the underlying bone is due to pressure rather than invasion

2.3. Painhas been reported as an occasional finding which could be attributed to secondary infection. Other effects include tooth mobility, displacement of teeth, resorption of roots, paraesthesia if the inferior alveolar canal is involved, failure of eruption of teeth and very rarely the ameloblastoma can ulcerate through the mucosa

3. Treatment

3.1. Marginal or en bloc resection

4. Introduction

4.1. True odontogenic tumor of enamel organ type tissue which has not undergone any differentiation at the time of enamel formation

4.1.1. Robinson has defined it as: Unicentric, nonfunctional, intermittent in growth, anatomically benign and clinically persistent.

5. Etiopathogenesis

5.1. Cell rests of the enamel organ, either remnants of the dental lamina or remnants of Hertwig’s sheath, the epithelial rests of Malassez. Epithelium of odontogenic cysts, particularly the dentigerous cyst, and odontomas. Disturbances of the developing enamel organ. Basal cells of the surface epithelium of the jaws. Heterotopic epithelium in other parts of the body, especially the pituitary gland.

6. Histopathology

6.1. Ameloblatoma cytologically usually presents with basaloid cells arranged in cells and clusters. These basaloid cells have scanty cytoplasm and dense oval nucleus. Palisading of these basaloid cells in cell clusters is a noticable feature. Additionally, squamous cells with abundant cytoplasm and central nucleus can also be seen if there is evidence of squamous metaplasia. The background is usually eosinophilic and shows scattered spindle cells and inflammatory cells.

7. Radiographic features

7.1. well defined, multilocular radiolucency with scalloped border typically described as 'honeycomb' or soap bubble appearance