Prostate adenocarcinoma mandibular metastasis associated with numb chin syndrome: a case report

The purpose of this study is to report a rare case of mandibular adenocarcinoma that was diagnosed due to metastasis from the prostate. Numb chin syndrome (NCS), which was associated with this case, is also discussed. Computed tomography (CT) and an intraoral incisional biopsy of the left mandibular area were performed. Urology consultation, hormone therapy, chemotherapy and follow-up radiographic images were administered. Histological examination of the incised specimen revealed moderately differentiated adenocarcinoma. The Gleason score was 8 (primary 4/secondary 4). Immunohistochemical features and radiographic results confirmed the diagnosis of metastasis from prostate adenocarcinoma, moderately differentiated. The patient's prostate-specific antigen (PSA) level was very high. After hormone treatment, the patient's PSA levels dropped gradually. Seventeen months later, in May 2015, the PSA level was elevated. The 18-month follow-up CT image indicated that the patient's condition was aggravated. Docetaxel chemotherapy was started in June 2015 (18 months later), and the sixth cycle of the therapy is in progress. Oral metastases that originate from prostate adenocarcinoma are rare and can induce various periosteal reactions. Hormone therapy, chemotherapy and close follow-up could be additional, appropriate treatment, and were applied in this case. Finally, NCS is a valuable indicator of metastatic disease in the mandible.