The incidence of prostate cancer has become greater as longevity increases. The prostate adenocarcinoma is a slow-growing tumor that shows usual hematogenous spread to the bone. However, the frequency of metastasis to the maxillofacial region is low, being the mandible more commonly affected when it happens in this region. This paper presents a case of mandibular metastasis of an adenocarcinoma of the prostate, diagnosed prior to the discovery of the primary tumor. At the initial examination, the patient SM, 73, male, mulatto, referred intense pain and swelling of the left jaw. Initially, it was requested a panoramic radiography, which showed diffuse radiolucency. To clarify the boundaries of the lesion, CT scan was requested, followed by biopsy of the area. The pathological diagnosis was malignant neoplasm of epithelial origin, however it was unclear from which tissue it came from. It was suggested the performance of immunohistochemistry. This, in turn, presented positive for EMA and negative for PSA and Ki-67, p63, CDX2, vimentin, CEA, CA19.9, and CK20 CK7. The immunohistochemical diagnostic panel resulted in bone metastasis of adenocarcinoma of prostatic origin. The patient was referred to the urologist for evaluation. A pelvic ultrasound was performed, which demonstrated an enlargement of the area, followed by biopsy of the prostate, which concluded the diagnosis of adenocarcinoma. Then, scintigraphy was made and demonstrated metastasis to other parts of the body. Due to the advancement of the patient’s decease, he was sent to palliative chemotherapy treatment.

Conflict of interest: None declared.