Successful management of rare gingival metastasis from gastric adenocarcinoma: a case report and literature review

Background: Gastric cancer rarely metastasizes to the oral cavity, especially to gingiva. Only 18 cases have been reported worldwide to date. This paper herein presents the nineteenth case of gingival metastasis from gastric cancer. Case presentation: A 75-year-old man who underwent a radical gastrectomy for gastric adenocarcinoma was admitted to clinical oncology center for gingival mass which was originally diagnosed as epulis. The subsequent positron emission tomography-computed tomography (PET-CT) and histopathological examination revealed a gingival metastatic adenocarcinoma originated from gastric carcinoma. Then three-dimensional conformal radiotherapy (3D-CRT) with synchronization and sequential chemotherapy demonstrated clinical benefit in this patient. Furthermore, this research reviewed the records of 18 cases of gingival metastasis from gastric carcinoma in English, Japanese, and Chinese literature, and summarized the clinicopathologic features of the disease based on previously published papers. Conclusion: This case suggests that gingival metastasis from gastric cancer is worthy of vigilance. Biopsy and immunohistochemical (IHC) staining should be used for the final diagnosis. Moreover, the patient with uncommon gingival metastatic lesion can be successfully treated by radiotherapy with adjuvant chemotherapy.