Ichimura Shinya, Hara Koichi, Shimokawa Reiko, Kagami Hiroshi, Inaba Makoto
Department of Neurosurgery, Saiseikai Yokohamashi Tobu Hospital.
Neurol Med Chir (Tokyo). 2013;53(10):699-702. doi: 10.2176/nmc.cr2012-0124. Epub 2013 Sep 24.
Both intraosseous and microcystic meningiomas are rare tumor types. We report the case of a 66-year-old woman with intraosseous microcystic meningioma without a mass lesion. She presented with a rare intraosseous microcystic meningioma manifesting as pain. Radiological examination revealed an osteolytic lesion in the right parietal bone. Magnetic resonance (MR) images showed iso- to hypointensity on T1-weighted images and hyperintensity on T2-weighted images corresponding to the lesion. T1-weighted MR imaging with gadolinium enhancement better defined the marginal area. The inner table of the skull was disrupted prominently, and both sides of the outer table were eroded. There was fluid leakage during surgery but no obvious tumor mass. Histological examination revealed microcystic meningioma in the inner part of the defective bone. A macroscopic lesion was not found, because most of the tumor comprised microcysts, and their contents leaked out during the surgical procedure. Intraosseous microcystic meningioma may be considered as one of the differential diagnoses when the intraosseous tumor in the skull has fluid leakage and does not have a mass lesion during the surgery.
骨内型和微囊型脑膜瘤均为罕见的肿瘤类型。我们报告了一例66岁女性骨内微囊型脑膜瘤病例，该病例无肿块病变。她表现为罕见的以疼痛为症状的骨内微囊型脑膜瘤。影像学检查显示右侧顶骨有溶骨性病变。磁共振（MR）图像显示，对应病变在T1加权图像上呈等信号至低信号，在T2加权图像上呈高信号。钆增强T1加权MR成像能更好地显示边缘区域。颅骨内板明显中断，外板两侧被侵蚀。手术中出现液体渗漏，但未发现明显肿瘤肿块。组织学检查显示缺损骨内部为微囊型脑膜瘤。未发现肉眼可见病变，因为大部分肿瘤由微囊组成，且其内容物在手术过程中漏出。当颅骨内肿瘤出现液体渗漏且手术中无肿块病变时，骨内微囊型脑膜瘤可被视为鉴别诊断之一。
