Matyja E, Naganska E, Zabek M, Jagielski J
Department of Experimental and Clinical Neuropathology, Medical Research Centre, Polish Academy of Sciences, Bródnowski District Hospital, Warsaw, Poland.
Clin Neuropathol. 2005 Nov-Dec;24(6):257-61.
Meningiomas exhibit a broad spectrum of differentiation potency corresponding to different histological subtypes. The separate secretory or lipomatous transformation of meningothelial cells is uncommonly encountered in meningiomas classified into distinct secretory or lipomatous variants. The coexistence of these two different histological subtypes is extremely rare. We report an exceptional case of secretory meningioma associated with extensive lipomatous component in a 58-year-old woman. CT scan and MRI of the brain showed a well-defined tumor mass in the right temporal lobe with areas of adipose tissue and extensive surrounding brain edema. Microscopically, the tumor was composed of two components: whorls of meningothelial cells with numerous PAS-positive hyaline inclusions (pseudopsammoma bodies) and numerous mature adipocyte-like cells. The presence of neutral fat was confirmed by oil-red-O staining. The hyaline inclusions and tumor cells surrounding them showed strong immunoreactivity for EMA and CEA. Ultrastructural findings confirmed both secretory and lipomatous differentiation of tumor cells. The majority of lipidized neoplastic cells shared the features of meningothelial cells and adipocytes. Our result supports the opinion that lipomatous component ought to be considered as an advanced lipidization of neoplastic meningothelial cells rather than true metaplastic transformation of meningothelial cells into mature fat tissue. The present case of meningioma demonstrates a unique coexistence of secretory and lipomatous meningothelial components, reflecting the multipotency of phenotypic transformation of primary meningothelial cells.
脑膜瘤表现出与不同组织学亚型相对应的广泛分化潜能。在分类为不同分泌型或脂肪瘤型变体的脑膜瘤中，脑膜内皮细胞单独的分泌性或脂肪瘤样转化并不常见。这两种不同组织学亚型的共存极为罕见。我们报告了一例58岁女性的分泌性脑膜瘤合并广泛脂肪瘤成分的特殊病例。脑部CT扫描和MRI显示右颞叶有一个边界清晰的肿瘤肿块，伴有脂肪组织区域和广泛的周围脑水肿。显微镜下，肿瘤由两种成分组成：带有大量PAS阳性透明包涵体（假砂粒体）的脑膜内皮细胞漩涡和大量成熟的脂肪细胞样细胞。油红O染色证实了中性脂肪的存在。透明包涵体及其周围的肿瘤细胞对EMA和CEA呈强免疫反应性。超微结构结果证实了肿瘤细胞的分泌性和脂肪瘤样分化。大多数脂质化的肿瘤细胞兼具脑膜内皮细胞和脂肪细胞的特征。我们的结果支持这样一种观点，即脂肪瘤成分应被视为肿瘤性脑膜内皮细胞的晚期脂质化，而不是脑膜内皮细胞真正化生为成熟脂肪组织。本例脑膜瘤展示了分泌性和脂肪瘤样脑膜内皮成分的独特共存，反映了原发性脑膜内皮细胞表型转化的多能性。
