Emmerling Max R, York Teresa A, Caccamese John F
Resident, Department of Oral and Maxillofacial Surgery, University of Maryland School of Dentistry, Baltimore, MD.
Assistant Professor and Interim Division Head, Division of Pediatric Hematology and Oncology, University of Maryland School of Medicine, Baltimore, MD.
J Oral Maxillofac Surg. 2019 Feb;77(2):315-320. doi: 10.1016/j.joms.2018.09.033. Epub 2018 Oct 5.
Melanotic neuroectodermal tumor of infancy (MNTI) is a rare pigmented tumor of the head and neck, which most commonly presents during the first year of life. Most cases present in the bones of the craniofacial region, including the maxilla (60.3%), skull (18.1%), and mandible (10.3%). The alveolar crest of the anterior maxilla is the most common site. MNTIs are locally aggressive, but benign, lesions derived from neural crest cells. However, they have a high rate of recurrence, and ≤6.5% of cases will demonstrate metastasis to lymph nodes or distant organs. They present clinically as an expansile pigmented mass. Radiographically, these lesions are often intraosseous expansile lytic lesions that can envelope or displace teeth. Extraosseous components might be better visualized on magnetic resonance imaging, demonstrating an enhancing iso- or hypointense mass on T1- and/or T2-weighted imaging. MNTIs have a distinctive biphasic cell population composed of large pigmented epithelial cells and small blue neuroblastic cells. Many immunohistochemical markers have also been identified. The large cell population often expresses cytokeratins, HMB-45, and vimentin; S100 is much less common. The small cell population typically expresses synaptophysin but will be negative for another neuroendocrine marker, chromogranin A. Rarely, patients will have elevated levels of urine vanillylmandelic acid, similar to findings from other tumors of neuroectodermal origin, such as neuroblastomas. First-line treatment of these lesions should be surgery with the goal of complete local excision. Radiotherapy and chemotherapy have been described but have been largely used as adjuvant or neoadjuvant therapy and for metastatic disease. We present a case of MNTI in an 8-week-old male, who had presented with a nonpigmented mass of the mandible associated with a pathologic fracture. In addition to a review of the data, our case serves to highlight potential prognostic factors, current clinical management, and local complications of this rare tumor.
婴儿黑色素性神经外胚层肿瘤（MNTI）是一种罕见的头颈部色素性肿瘤，最常见于出生后的第一年。大多数病例出现在颅面部区域的骨骼中，包括上颌骨（60.3%）、颅骨（18.1%）和下颌骨（10.3%）。上颌骨前部牙槽嵴是最常见的部位。MNTI是起源于神经嵴细胞的局部侵袭性但良性的病变。然而，它们的复发率很高，≤6.5%的病例会出现淋巴结或远处器官转移。临床上，它们表现为一个膨胀性色素性肿块。在影像学上，这些病变通常是骨内膨胀性溶骨性病变，可包绕或移位牙齿。磁共振成像可能更易显示骨外成分，在T1加权和/或T2加权成像上表现为强化的等密度或低密度肿块。MNTI有独特的双相细胞群，由大的色素上皮细胞和小的蓝色神经母细胞组成。许多免疫组化标志物也已被识别。大细胞群通常表达细胞角蛋白、HMB-45和波形蛋白；S100较少见。小细胞群通常表达突触素，但对另一种神经内分泌标志物嗜铬粒蛋白A呈阴性。很少有患者尿香草扁桃酸水平升高，这与其他神经外胚层起源的肿瘤如神经母细胞瘤的表现相似。这些病变的一线治疗应是手术，目标是完全局部切除。放疗和化疗也有报道，但主要用作辅助或新辅助治疗以及用于转移性疾病。我们报告一例8周大男性的MNTI病例，该患者表现为下颌骨非色素性肿块并伴有病理性骨折。除了对数据的回顾，我们的病例有助于突出这种罕见肿瘤的潜在预后因素、当前临床管理及局部并发症。
