Mirich D R, Blaser S I, Harwood-Nash D C, Armstrong D C, Becker L E, Posnick J C
Department of Diagnostic Radiology, Hospital for Sick Children, University of Toronto, Ontario, Canada.
AJNR Am J Neuroradiol. 1991 Jul-Aug;12(4):689-97.
Five pathologically proved melanotic neuroectodermal tumors of infancy are reported. These rare neoplasms of infancy exhibit a distinct predilection for the maxillary bone. Three tumors originated in the maxilla, one in the calvaria, and one in the cerebellar vermis. Those occurring in bone did not metastasize but were locally invasive, as reflected in their radiologic appearance. Bone erosion, expansion, hyperostosis, and osteogenesis can occur in the same neoplasm and were appreciated best on CT. MR imaging showed the soft-tissue component and extent of the neoplasm better than CT did. The pathologic findings from all five cases (and one possibly related melanotic tumor of the face) revealed abundant melanin. MR imaging of two melanotic tumors showed isointense T1-weighted and slightly hyperintense T2-weighted signals. This appearance is contrary to that of most melanin-containing tumors, which exhibit enhanced T1 and T2 relaxation, and indicates that variables other than the absolute amount of melanin may determine the MR signal. Clinically, rapid neoplastic growth and excessive melanin production by the tumor cells caused facial disfigurement and visible blue black discoloration. All five melanotic neuroectodermal tumors were resected and the vermian tumor was also irradiated. Four of five children were well and free from disease 1 month to 7 years after resection. The calvarial tumor was incompletely resected and involved the underlying brain, eventually causing death. The clinical, radiologic, and pathologic features of melanotic neuroectodermal tumors of infancy are reviewed. Melanotic neuroectodermal tumors of infancy that involve bone can be diagnosed from the clinical and radiologic findings. Prompt diagnosis and surgical resection are essential for cure.
报告了5例经病理证实的婴儿黑色素性神经外胚层肿瘤。这些罕见的婴儿肿瘤明显好发于上颌骨。3例肿瘤起源于上颌骨，1例起源于颅骨，1例起源于小脑蚓部。发生于骨骼的肿瘤不发生转移，但具有局部侵袭性，这在其放射学表现中有所体现。骨侵蚀、膨胀、骨质增生和成骨可在同一肿瘤中出现，CT能最佳地显示这些表现。磁共振成像（MR成像）比CT更能显示肿瘤的软组织成分及其范围。所有5例病例（以及1例可能相关的面部黑色素性肿瘤）的病理结果均显示有丰富的黑色素。2例黑色素性肿瘤的MR成像显示T1加权像呈等信号，T2加权像呈轻度高信号。这种表现与大多数含黑色素肿瘤相反，后者T1和T2弛豫增强，这表明除黑色素的绝对含量外，其他变量可能决定MR信号。临床上，肿瘤细胞的快速生长和过量黑色素产生导致面部畸形和可见的蓝黑色色素沉着。所有5例黑色素性神经外胚层肿瘤均行手术切除，蚓部肿瘤还进行了放疗。5例患儿中有4例在切除术后1个月至7年情况良好，无疾病复发。颅骨肿瘤切除不完全，累及下方脑组织，最终导致死亡。本文对婴儿黑色素性神经外胚层肿瘤的临床、放射学和病理学特征进行了综述。累及骨骼的婴儿黑色素性神经外胚层肿瘤可根据临床和放射学表现做出诊断。及时诊断和手术切除是治愈的关键。
