Musculoskeletal

Allison Zwingenberger

University of California, Davis

Allison Zwingenberger 2008
Publication Date: 2008-08-13

Document	Image Export

History

11 year old female neutered Labrador Retriever. Owner recently noticed a mass under the right orbit.

Findings

There is an expansile lesion within the right maxillary bone and temporal process of the zygomatic bone. This lesion involves the tooth roots of the right maxillary first molar. The right maxillary fourth premolar is absent, and is likely secondary to the mass. There is a small amount of mineralization of the horizontal ear canals bilaterally. There was no evidence of enlarged lymph nodes on soft tissue window.

DDx

• ameloblastoma
• odontoma
• other odontogenic tumor

Diagnosis

Ameloblastoma

Discussion

These tumors of odontogenic origin tend to be locally invasive but not metastatic. The expansion of bone suggests a slow-growing mass that has benign characteristics. In this case, surgical excision would have required enucleation to obtain clean margins, so was not pursued.

Further information on these tumors is available at http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2003&PID=6558&O=Generic.