A 65-year-old woman with breast cancer diagnosed 2 years ago presents with a poorly defined radiolucent lesion in the posterior maxilla between teeth #2 and #3. What is the most likely diagnosis?

Correct answer: C. Bone metastasis from breast cancer

• A. Ameloblastoma typically presents as a multilocular 'soap bubble' radiolucency in the posterior mandible. Maxillary ameloblastoma is less common.
• B. Traumatic bone cyst presents as a well-defined radiolucency with scalloped margins between roots, typically in young patients — not associated with cancer history.
• C. CORRECT. Breast cancer is one of the most common cancers to metastasize to the jaw bones. Metastatic lesions in the jaws typically appear as irregular, 'moth-eaten' radiolucencies. The patient's history of breast cancer and the atypical, poorly defined radiolucency make metastatic disease the most important diagnosis to rule out.
• D. OKC is a well-defined, unilocular or multilocular radiolucency with a smooth scalloped corticated border, typically occurring in younger patients. It doesn't fit the presentation of an irregular lesion in a cancer patient.