Gil-Salú J L, Rodríguez-Peña F, López-Escobar M, Palomo M J
Servicios de Neurocirugía. Hospital Universitario Puerta del Mar. Cádiz.
Neurocirugia (Astur). 2004 Jun;15(3):285-9. doi: 10.1016/s1130-1473(04)70485-6.
Differences in the imaging characteristic of adult medulloblastomas have been reported, including involvement of lateral cerebellar hemispheres with an extra-axial appearance. We present a case report of this rare circumstance: a 40 year old man presented with a 3 weeks history of headache, morning vomiting and left hearing difficulties. Magnetic resonance imaging revealed a left cerebellopontine angle (CPA) tumor, like a well circumscribed homogeneously enhancing mass. Through a left suboccipital craniectomy the tumor was totally removed. It presented as a cerebellopontine angle tumor, like a meningioma, and not as an intra-axial tumor. Histological analysis revealed that the tumor was composed of densely packed with highly proliferative cells that produce a dense intercellular reticulin fiber network. Inmunohistochemical analysis showed positive expression to synaptophysin, specific neuronal enolase and cromogranin. Histological diagnosis was crucial to define it as a desmoplastic medulloblastoma the present case and to perform postoperative adjuvant therapy. Neurosurgeons should be aware of the possibility that a CPA tumor is of intraaxial origin, because this increase the variability on pathological diagnosis.
已有报道指出成人髓母细胞瘤在影像学特征上存在差异，包括小脑半球外侧受累并呈现轴外表现。我们报告了这样一个罕见病例：一名40岁男性，有3周的头痛、晨起呕吐及左耳听力困难病史。磁共振成像显示左侧桥小脑角（CPA）有一个肿瘤，表现为边界清晰、均匀强化的肿块。通过左枕下开颅手术，肿瘤被完全切除。它表现为桥小脑角肿瘤，类似脑膜瘤，而非轴内肿瘤。组织学分析显示，肿瘤由紧密排列的高增殖细胞组成，这些细胞产生密集的细胞间网状纤维网络。免疫组化分析显示突触素、特异性神经元烯醇化酶和嗜铬粒蛋白呈阳性表达。组织学诊断对于将本例定义为促纤维增生型髓母细胞瘤并进行术后辅助治疗至关重要。神经外科医生应意识到CPA肿瘤可能起源于轴内，因为这会增加病理诊断的变异性。
