Kingdom T T, Lalwani A K, Pitts L H
Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of California, San Francisco.
Neurosurgery. 1993 Jul;33(1):142-4. doi: 10.1227/00006123-199307000-00024.
Malignant melanoma is a common cause of central nervous system metastases. This report describes an extremely rare case of metastatic melanoma presenting as an isolated cerebellopontine angle tumor. Clinically and radiographically, the lesion mimicked an acoustic neuroma. The patient had neuro-otological symptoms, including tinnitus, vertigo, sensorineural hearing loss, facial nerve dysfunction, and prominent cerebellar dysfunction. Magnetic resonance images showed a lesion of the internal auditory canal and cerebellopontine angle that was hypointense on T1-weighted images, hyperintense on T2-weighted images, and enhanced after the administration of gadolinium. T2-weighted images showed significant cerebellar edema. Subtotal resection of the tumor through a suboccipital craniotomy palliated the symptoms, but the patient died of tumor progression 6 months later. In contrast to other metastatic tumors of the temporal bone, melanoma initially metastasizes to the internal auditory canal and is characterized by early neurovascular infiltration. This report highlights the pathophysiological characteristics, radiological findings, differential diagnosis, and treatment of metastatic melanoma of the internal auditory canal and cerebellopontine angle.
恶性黑色素瘤是中枢神经系统转移的常见原因。本报告描述了一例极为罕见的转移性黑色素瘤病例，其表现为孤立的桥小脑角肿瘤。在临床和影像学上，该病变酷似听神经瘤。患者有神经耳科症状，包括耳鸣、眩晕、感音神经性听力损失、面神经功能障碍以及明显的小脑功能障碍。磁共振成像显示内耳道和桥小脑角有一病变，在T1加权图像上呈低信号，在T2加权图像上呈高信号，注射钆后强化。T2加权图像显示小脑明显水肿。通过枕下开颅术对肿瘤进行次全切除缓解了症状，但患者6个月后死于肿瘤进展。与颞骨的其他转移性肿瘤不同，黑色素瘤最初转移至内耳道，其特点是早期神经血管浸润。本报告强调了内耳道和桥小脑角转移性黑色素瘤的病理生理特征、影像学表现、鉴别诊断及治疗。
