Hepatoid Adenocarcinoma Of The Lung Metastasizing To The Gingiva

BACKGROUND: Hepatoid adenocarcinoma (HAC) of the lung, a very rare tumor, has been reported metastasizing to lymph nodes and distant tissue, with poor prognosis. We report a case of lung HAC metastasizing to the gingiva, which is a rare metastasis site. CASE REPORT: A 70-year-old, 50-pack-year, male smoker was diagnosed with a lung mass on a health examination. A chest CT showed a lung mass in the superior lobe of the right lung and enlarged lymph nodes in the right hilum and mediastinum. Liver and other digestive tumors were excluded. The lung mass was confirmed to be HAC by biopsy with positivity of HepPar-1. Despite erlotinib therapy, the tumor metastasized to the gingiva. Then, docetaxel and nedaplatin therapy, radiotherapy, and bevacizumab therapy were administered successively. The patient died of tumor progression 9 months after presentation. CONCLUSION: Gingival metastasis of lung HAC is rare. The patient had a poor outcome. Further studies need to be conducted on lung HAC.