The osteoblastic activity of carcinoma is restricted in osteoblastic metastasis, common in the patients with prostate cancer, whereas its mechanism and the factors involved are unknown. Here, we present a case of central adenocarcinoma showing the osteoblastic activity in the mandible of the 80-year-old Korean male who had suffered from the paresthesia of lower lip during four mouths. Clinically the overlying oral epithelium was intact, but the radiologic images revealed the ill-defined radiolucent intraosseous lesions in left ascending ramus. Microscopically, the mandibular lesion was composed with carcinoma of ductal or glandular differentiation but lack typical features of any epithelial salivary gland malignancies. Intriguingly abundant new bone formation was found in the stroma, but the tumor cells expressed no reactivity for prostate-specific antigen(PSA). The patient had low ionized calcium level, normal serum alkaline phosphatase and PSA level. Positron emission tomography-computed tomopraphy scan revealed the benign prostatic hyperplasia, but failed to trace the primary site of tumor other than mandible. Therefore, pathologically diagnosis for the lesion was informed as adenocarcinoma, not otherwise specified(NOS). Because occult primary tumor associated with osteoblastic metastasis cannot be completely ruled out, periodic and careful check-ups for the patient should be performed.

• 김형근(연세대학교 치과대학 구강악안면외과학교실) | Hyoung Keun Kim
• 이충상(연세대학교 치과대학 구강악안면외과학교실) | Choong Sang Lee
• 양동현(구강병리학교실) | Dong Hyun Yang
• 김형준(연세대학교 치과대학 구강악안면외과학교실) | Hyung Jun Kim
• 정호걸(구강악안면방사선학교실) | Ho Gul Jung
• 육종인(구강병리학교실, 구강종양연구소) | Jong In Yook
• 김현실(구강종양연구소) | Hyun Sil Kim correspondence