Kami Yukiko, Chikui Toru, Fujii Shinsuke, Fujimoto Tatsufumi, Kumamaru Wataru, Hasegawa Kana, Nakamatsu Koji, Okamura Kazutoshi, Yasaka Misa, Kiyoshima Tamotsu, Yoshiura Kazunori
Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
Oral Radiol. 2025 Apr;41(2):302-309. doi: 10.1007/s11282-024-00788-w. Epub 2024 Nov 23.
Primary intraosseous carcinoma not otherwise specified (PIOC NOS) is a rare tumor assumed to arise from the epithelium, such as odontogenic cysts or benign tumors. Its clinical and imaging diagnoses are often challenging, especially in the early stages, as it mimics jaw cysts and benign tumors, and no specific findings have been identified. This report presents the case of a 66-year-old male patient with mandibular PIOC, highlighting the imaging findings over time. Magnetic resonance imaging (MRI) before symptom onset showed a cystic lesion in the right mandible with a soft tissue component. Both the fluid component and soft tissue exhibited low apparent diffusion coefficient values (1.0 × 10 mm/s and 1.3 × 10 mm/s, respectively). Subsequent MRI approximately 5 months later during symptom onset showed a slight increase in the soft tissue component. Based on the clinical and imaging findings, ameloblastoma was suspected, prompting a biopsy for confirmation. However, the histopathological findings showed squamous cell carcinoma (SCC). MRI performed approximately 1 month later exhibited significant tumor growth and extension beyond the jawbone, consistent with a malignant tumor. Histopathological examination identified areas with a basal layer in a palisading arrangement, indicating a pre-existing odontogenic cyst, and showed a transition from epithelial dysplasia to SCC. In addition, carcinoma cell invasion and proliferation into the cyst were observed. Based on these findings, PIOC of the right mandible was determined to be the definitive diagnosis.
未另行规定的原发性骨内癌（PIOC NOS）是一种罕见肿瘤，推测起源于上皮组织，如牙源性囊肿或良性肿瘤。其临床和影像学诊断通常具有挑战性，尤其是在早期阶段，因为它与颌骨囊肿和良性肿瘤相似，且尚未发现特异性表现。本报告介绍了一名66岁男性下颌骨PIOC患者的病例，重点展示了随时间变化的影像学表现。症状出现前的磁共振成像（MRI）显示右下颌骨有一个含软组织成分的囊性病变。液体成分和软组织的表观扩散系数值均较低（分别为1.0×10⁻³mm²/s和1.3×10⁻³mm²/s）。症状出现时约5个月后的后续MRI显示软组织成分略有增加。基于临床和影像学表现，怀疑为成釉细胞瘤，遂进行活检以确诊。然而，组织病理学检查显示为鳞状细胞癌（SCC）。约1个月后进行的MRI显示肿瘤显著生长并超出颌骨范围，符合恶性肿瘤表现。组织病理学检查发现有呈栅栏状排列的基底层区域，提示存在先前的牙源性囊肿，并显示从上皮发育异常向SCC的转变。此外，观察到癌细胞侵入并增殖至囊肿内。基于这些发现，确诊为右下颌骨PIOC。
