Basal cell adenocarcinoma is an epithelial neoplasm with the cytological characteristics of basal cell adenoma but with a morphological pattern of infiltrative growth indicative of malignancy. Due to its low incidence it is often difficult to diagnose a basal cell adenocarcinoma. The objective of the present study was to identify morphological and immunohistochemical characteristics that contribute to its diagnosis. A parotid tumor was resected in a 52-year-old patient; postoperative biopsy and immunostaining with Ki-67, CK19, p63 and alpha-smooth muscle actin were performed. It was diagnosed basal cell adenocarcinoma that invades the tumor capsule, periglandular fat and lymph nodes. Immunostaining with Ki-67, CK19, p63 and alpha-smooth muscle actin was positive. Subsequently, a maxillary sinus metastasis was diagnosed. The morphological characteristics, Ki-67 expression strongly positive and metastasis give the malignant character to this tumor, which differentiates it from the basal cell adenoma.