Ameloblastoma

Ameloblastoma is a benign but locally aggressive odontogenic tumor that typically arises in the mandible.

Location

Mandible: Most common site (80-85%), particularly in the molar-ramus region.
Maxilla: Less common but more aggressive due to proximity to critical structures (e.g., sinus, orbit).

Multiloculated radiolucency: Classic "soap-bubble" or "honeycomb" appearance, especially in the mandible.
Unilocular lesions: May occur in smaller or early-stage lesions, often mimicking other cystic conditions like dentigerous cysts.
Cortical thinning and expansion: Ameloblastomas cause significant bone expansion with thinning of the cortex but often without perforation.
Root resorption: Adjacent teeth often show root resorption, a key feature that differentiates it from other lesions.

Well-defined, expansile lesion: CT is superior for evaluating cortical bone involvement.
Mixed density: Primarily lytic with thin septations in multilocular cases.
Cortical breach: Look for any erosion of the cortex, especially in larger lesions.
Soft tissue involvement: Advanced cases may show soft tissue extension.

T1-weighted: Typically hypointense.
T2-weighted: Hyperintense (fluid-filled cystic areas); septations may appear hypointense.
Post-contrast enhancement: Heterogeneous enhancement due to the solid-cystic nature, with enhanced septa and mural nodules.

Odontogenic keratocyst (OKC): Similar radiolucent appearance but less expansion and typically without root resorption.
Dentigerous cyst: Often associated with an unerupted tooth (usually 3rd molar); usually unilocular.
Odontogenic myxoma: May appear multilocular but with less aggressive features.

Surgical resection: The treatment of choice, often requiring wide margins due to high recurrence rates.
Recurrence: Ameloblastomas have a high recurrence rate if not completely excised. Imaging plays a role in detecting post-treatment recurrence.

Postoperative: Look for residual or recurrent disease on follow-up CT or MRI.
Bone graft monitoring: If reconstructive surgery is performed, follow-up imaging can assess graft viability.