A case of the pleomorphic adenoma of minor salivary gland that resulted in maxillary metastasis 20 years after primary tumor resection

In addition to this case, we undertook a review of the literature about all identified MPA cases that the minor salivary gland origin reported in the English language up to 2015. The most frequent primary site was the palate (66.7%), and the most frequent metastatic site was the cervical lymph nodes (33.3%). The mean interval from primary tumor to metastasis was 8.9 years and all cases were treated with surgical resection for MPA, except for one. PA should be followed up with consideration of metastasis over the long term.