Clinical case description of a papillary mucinous cystadenocarcinoma, extremely rare malignant tumor in the salivary gland and difficult to diagnose, in geriatric patient. Patient with 86 years old was referred for treatment with nodular lesion on the inner side of left lower lip extending to the bucal mucosa, without any clinical appearances of malignancy. The lesion was asymptomatic, had flabby consistency and slow growth. Despite the favorable clinical features, after surgical removal, was diagnosed as papillary mucinous papillary mucinous cystadenocarcinoma. Nonetheless, the cellular atypia found was considered to be mild and immunohistochemical evaluation the reaction to Ki-67 was low, indicating a low rate of proliferation of the tumor. Medical evaluation confirmed the absence of systemic disorders or distant metastases. Although it is a malignant lesion, due to low degree of proliferation of lesion and the careful follow-up carried out, there was a favorable evolution after conservative treatment in a follow-up period of 11 years and six months.642207211