Pulmonary Metastasis of Mandibular Amelobastoma: A Case Report

Abstract

SESSION TITLE: Lung Cancer 2 SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Tuesday, October 31, 2017 at 07:30 AM - 08:30 AM INTRODUCTION: Ameloblastoma is an odontogenic tumor originating from the enamel of the teeth. Although benign, local recurrent tissue growth can be aggressive. While distant metastasis to the lung is rare, early diagnosis can translate into effective treatment implementation. CASE PRESENTATION: A 72 year old male presented to the emergency department twelve years after undergoing mandibulectomy for mandibular amelobastoma. This benign neoplasm did recur once locally for which he underwent definitive treatment with radiation therapy. He presented with complaints of sudden onset chest pain that was pleuritic and non-radiating. The pain lasted thirty minutes and dissipated spontaneously. He had a non-productive cough but denied any hemoptysis or constitutional symptoms. Patient was vitally stable with an unremarkable physical exam. Pertinent imaging is shown below. Ultimately, bronchoscopy was performed and a large, exophytic endobronchial lesion of the left lower lobe was biopsied. Histopathological staining pattern revealed cells consistent with metastatic ameloblastoma. DISCUSSION: Metastasis is the active or passive dissemination of neoplastic disease from site of origin to distant organs, usually due to a malignant condition. Ameloblastoma is a benign tumor with locally aggressive behavior that can also metastasize. This occurs after an interval ranging from 10-12 years and the lungs are involved in 75-80% of cases. Histopathologically, these tumors have well-differentiated, benign features but are clinically metastatic. The mechanism for metastatic spread remains debatable. Seeding from surgical manipulation of the primary tumor, in its odontogenic form, suggests that aspiration may contribute. However, the presence of tumor cells in surrounding blood vessels suggests hematogenous spread of disease. Intense 18-fluorodeoxyglucose (FDG) activity seen on positron emission tomography (PET) scan may reflect the aggressiveness of the disease. CONCLUSIONS: Pulmonary ameloblastoma is a rare metastatic neoplasm that is not necessarily malignant. Its radiologic and histopatholgical features aid in attaining correct diagnosis and ultimately lead physicians towards an appropriate treatment plan. Reference #1: Bi et al. Maligant ameloblastoma in the lung: 3 cases of misdiagnosis as primary lung tumor with a unique growth pattern. Diagnostic Pathology (2015) 10:123-129. Reference #2: Rabo et al. Mandibular Ameloblastoma with Lung Metastasis 10 Years after Resection. Philipp J Otolaryngol head Neck Surg. (2016); 31(1):53-56 DISCLOSURE: The following authors have nothing to disclose: Kevin Charles, Ashley Ferraro, Michael Constantinescu, Adil Yousuf No Product/Research Disclosure Information