Ogura Ichiro, Sasaki Yoshihiko, Kameta Ayako, Sue Mikiko, Oda Takaaki
Chin J Dent Res. 2017;20(2):111-114. doi: 10.3290/j.cjdr.a38276.
Malignant melanoma of the mandibular gingiva is extremely rare. It is a malignant tumour of melanocytes or their precursor cells, and often misinterpreted as a benign pigmented process. A few reports have described computed tomography (CT) and magnetic resonance imaging (MRI) findings of malignant melanoma in the oral cavity. We report a rare case of malignant melanoma of the mandible and the related CT and MRI findings. Soft tissue algorithm contrast-enhanced CT showed an expansile mass and irregular destruction of alveolar bone in the right side of the mandibular molar area. MR images showed an enhancing mass and the tumour had a low to intermediate signal intensity and a high-signal intensity. Soft tissue algorithm contrast-enhanced CT and MR images showed lymphadenopathy involving the submandibular lymph nodes. Histopathological examination confirmed the diagnosis of malignant melanoma.
下颌牙龈恶性黑色素瘤极为罕见。它是黑素细胞或其前体细胞的恶性肿瘤，常被误诊为良性色素沉着病变。有少数报告描述了口腔恶性黑色素瘤的计算机断层扫描（CT）和磁共振成像（MRI）表现。我们报告一例罕见的下颌恶性黑色素瘤及其相关的CT和MRI表现。软组织算法增强CT显示下颌磨牙区右侧有一膨胀性肿块及牙槽骨不规则破坏。MR图像显示一强化肿块，肿瘤呈低至中等信号强度及高信号强度。软组织算法增强CT和MR图像显示下颌下淋巴结肿大。组织病理学检查确诊为恶性黑色素瘤。
