A Rare Distant Metastasis of Papillary Cystadenocarcinoma Arising from Maxillary Gingiva

Papillary cystadenocarcinoma is an uncommon disease with low-grade histological and clinical features. Although the tumor has the potential to produce regional lymph node metastasis, there have been no reports of cases with distant metastasis. We describe a case of papillary cystadenocarcinoma arising from the maxilla that developed pulmonary metastasis 3 years after radical surgery of the primary tumor and regional lymph node. The histological findings were confirmed on resected specimens of the pulmonary nodule and a pathological diagnosis of a metastatic lesion derived from papillary cystadenocarcinoma was made. To our knowledge, this is the first report of the development of pulmonary metastasis in a patient with papillary cystadenocarcinoma. The present case suggests that papillary cystadenocarcinoma has the potential to produce lung metastasis in the clinical course. Based on our experience, we emphasize that long-term follow-up and/or careful examination are necessary in patients with cystadenocarcinoma, especially in patients with lymph node metastasis during the initial surgical therapy.