Multiple organ metastases from ameloblastoma detected by FDG PET/CT imaging

89Zr-panitumumab PET imaging for preoperative assessment of ameloblastoma in a PDX model

Accurate assessment of tumor margins with specific, non-invasive imaging would result in the preservation of healthy tissue and improve long-term local tumor control, thereby reducing the risk of recurrence. Overexpression of epidermal growth factor receptor (EGFR) has been used in other cancers as an imaging biomarker to identify cancerous tissue. We hypothesize that expression of EGFR in ameloblastomas may be used to specifically visualize tumors. The aims of this study are to measure the specificity of radiolabeled 89Zr-panitumumab (an EGFR antibody) in vivo using patient-derived xenograft (PDX) models of ameloblastoma and positron emission tomography/computed tomography (PET/CT) scans. In PDX of ameloblastomas from four patients (AB-36, AB-37, AB-39 AB-53), the biodistribution of 89Zr-panitumumab was measured 120 h post-injection and was reported as the injected dose per gram of tissue (%ID/g; AB-36, 40%; AB-37, 62%; AB-39 18%; AB-53, 65%). The radiolabeled %ID/g was significantly greater in tumors of 89Zr-panitumumab-treated mice that did not receive unlabeled panitumumab as a blocking control for AB-36, AB-37, and AB-53. Radiolabeled anti-EGFR demonstrates specificity for ameloblastoma PDX tumor xenografts, we believe 89Zr-panitumumab is an attractive target for pre-surgical imaging of ameloblastomas. With this technology, we could more accurately assess tumor margins for the surgical removal of ameloblastomas.

Ameloblastic carcinoma with hepatic metastases: A case report and review of ameloblastomic carcinoma

Ameloblastic carcinoma is a locally aggressive odontogenic tumor that most commonly affects young and middle-aged adults. Metastatic disease may develop insidiously and manifest months or years after the initial diagnosis. Herein, we describe the clinical, imaging, and pathologic findings of a 31-year-old male who presented to the emergency department with headache and vision loss of 3 months duration and was subsequently found to have ameloblastic carcinoma with hepatic metastases. Initial computed tomography (CT) and magnetic resonance imaging revealed a multilocular cystic mass with avidly-enhancing nodular soft-tissue components associated with the right temporal fossa. Histologic examination of a tissue sample showed findings consistent with ameloblastic carcinoma. An initial staging CT scan showed several small hepatic cystic lesions. Follow-up surveillance imaging showed interval growth. A subsequent biopsy of a hepatic lesion showed findings compatible with metastatic ameloblastic carcinoma. The patient was started on systemic chemotherapy with evidence of disease progression at 1-year follow-up.

Metastasizing Ameloblastoma: A 10 Year Clinicopathological Review with an Insight Into Pathogenesis

Ameloblastoma, a benign but locally aggressive odontogenic tumor, often demonstrates metastasis despite benign histological features and this variant is termed as metastasizing ameloblastoma (METAM). It was classified under the malignant category in the 2005 WHO but has been re-classified under benign epithelial odontogenic tumors in the latest 2017 WHO classification. The present review aimed at gathering the available data on METAM to update the current cognizance about the pathology. Comprehensive search of the databases (viz., PubMed, Medline, SCOPUS, Web of Science, EMBASE and Google Scholar) was done for published articles on METAM following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 42 cases were extracted. The mean age of occurrence was 42.71 ± 15.87 years. A slight male predilection was noted. Mandibular cases showed more metastasis than maxillary cases. Follicular ameloblastoma was most frequently encountered at secondary site followed by plexiform type. Lungs were the most commonly affected secondary sites. METAM is a rare odontogenic tumor and the diagnosis is usually made in retrospect. Inadequate treatment may result in multiple recurrences and metastasis in rare instances. Metastasis in ameloblastoma appears to be multi-factorial in nature and needs further investigation in untapped territory like exploration of quantum effects at cellular and molecular levels.