左侧顶颞叶多形性黄色瘤型星形细胞瘤MRI表现
MR1见左侧顶颞叶囊性为主伴附壁结节肿块。A.附壁结节T1WI呈稍低信号;B.T2WI呈稍高信号C.T2-FLAIR呈稍高信号;D.增强扫描囊壁及附壁结节呈明显强化
多形性黄色星形细胞瘤 ( plemorphicxanthoastrocytoma,PXA)为 WHOⅡ级,仅占星形细胞起源肿瘤不足1%。病理学上肿瘤为边缘相对清楚的实性或伴部分囊变+壁结节的肿物,壁结节贴附于柔脑膜处,其脑实质侧界限欠清,呈浸润性生长。镜下肿瘤细胞呈多形性,可见致密网状纤维形成的网络。肿瘤细胞内含脂质呈泡沫状,体积较大,多核,因此可误诊为多形性胶质母细胞瘤。间变型 PXA约占10%-15%,肿瘤细胞密度增大,间变增加,并可伴血管增生及坏死,但目前WHO分类中尚无间变性PXA这一名称。免疫组织化学GFAP及S-100+),突触素及神经微丝蛋白(+)。本病主要见于青少年,其中18岁以下者占2/3。最常见临床表现为长期抽搐。本病预后良好,肿瘤全切者一般不复发,5 年生存率 80%。
Pleomorphic yellow astrocytoma (plemorphic xanthoastrocytoma, PXA) for the WHO Ⅱ level, only 1% of astrocytes on the origin of tumor is not sufficient. Pathologically, the tumor was a relatively clear solid at the margin or a mass with partial cystic degeneration + mural nodules, which attached to the soft meninges, and the lateral boundaries of the brain parenchyma were not clear, showing invasive growth. Microscopically, the neoplastic cells are pleomorphic, showing a network of dense reticular fibers. The tumor cells contain large, foam-like lipids with multiple nuclei, which may be misdiagnosed as glioblastoma multiformis. Mesenchymal PXA accounts for about 10%-15%, with increased tumor cell density, increased mesenchymal PXA, and associated vascular hyperplasia and necrosis. However, there is no such name as mesenchymal PXA in WHO classification at present. Immunohistochemistry GFAP and s-100 +), synaptophysin and neurofilament protein (+). The disease mainly occurs in adolescents, two-thirds of whom are under the age of 18. The most common clinical manifestation is chronic convulsion. This disease prognosis is good, the tumor is cut completely the person does not recur commonly,5 years survival rate 80%.
CT：PXA包括囊性为主伴附壁结节及实性肿块伴瘤内囊变两种形式,肿瘤多位于皮层表浅部位,囊性部分位于实性部分深侧。CT平扫囊性部分因含有蛋白或出血,表现为稍高于脑脊液的低密度,实性部分或壁结节为低、等、稍高或混杂密度,偶可见钙化,罕见颅骨侵蚀;增强扫描,壁结节明显强化,囊壁环形强化或不强化。
PXA can be divided into two forms: cystic primary mural nodules and solid mass with intratumoral cystic changes. The tumors are mostly located at the superficial part of the cortex, while the cystic part is at the deep side of the solid part. The cystic part of CT scan showed a slightly higher density than CSF due to protein or bleeding, while the solid part or wall nodules showed a low, equal, slightly higher or mixed density, with occasional calcification and rare skull erosion. On enhanced scan, the wall nodules were obviously strengthened, and the capsular wall was annular strengthened or not.
MRI：T1WI上囊性部分呈低信号,壁结节和实性部分呈等和低信号,边界较清楚,可有轻度瘤周水肿。T2WI囊性部分为高信号,壁结节和实性部分呈稍高信号。增强扫描后壁结节及实性部分明显强化,增强结节通常紧贴软脑膜表面, 囊性部分位于肿瘤边缘,不强化,囊壁强化或不强化,肿瘤附近的脑膜常可见强化.肿瘤的深部转移罕见。PXA实性部分在DWI上呈等或稍高信号,但ADC值高于相对正常的脑区,考虑为T2WI穿透效应所致,而实际上肿瘤并无明显弥散受限.
On T1WI, the cystic part showed low signal, while the wall nodules and solid part showed equal and low signal. The boundary was clear, and mild peritubercular edema could be observed. The cystic part of T2WI showed high signal, while the mural nodules and solid part showed slightly higher signal. The tubercle and solid part of the posterior wall of the enhanced scan were significantly enhanced, and the tubercle was usually close to the surface of the pia mater, while the cystic part was located at the edge of the tumor, which was not strengthened, and the cystic wall was strengthened or not strengthened, and the meningeal near the tumor was often strengthened. Deep metastasis of the tumor was rare. The solid part of PXA showed equal or slightly higher signal on DWI, but the ADC value was higher than the relatively normal brain region, which was considered to be caused by the penetration effect of T2WI, but in fact, the tumor was not significantly limited in diffusion.
PXA临床常以癫痫为主要症状,典型影像表现为脑表浅部位的囊和壁结节或实性为主伴其内囊变的肿块,偶见钙化,增强后壁结节及实性部分明显强化,囊性区无强化,可见瘤周水肿。以“囊性病变伴壁结节”为表现的PXA应与幕上毛细胞型星形细胞瘤、幕上血管母细胞瘤、节细胞胶质瘤相鉴别;以实性成分为主的应与炎性肉芽肿相鉴别。
Epilepsy is the main clinical symptom of PXA, and the typical imaging manifestations are cystic and wall nodules at the superficial part of the brain or solid masses with internal cystic changes. Calcification is occasionally seen, the strengthened posterior wall nodules and solid parts are significantly enhanced, while the cystic area is not strengthened, and perituberous edema can be seen. PXA with 'cystic lesions with mural nodules' should be differentiated from supratentorial hair cell astrocytoma, supratentorial hemangioblastoma and ganglion glioma. Solid components should be distinguished from inflammatory granulomas.
节细胞胶质瘤主要见于儿童及青年人, 好发于幕上大脑半球,颞叶最常见,典型节细胞胶质瘤为单囊和壁结节,壁结节常见钙化。
Ganglion gliomas are mainly found in children and young people. They tend to occur in the supraatentorial cerebral hemisphere. The temporal lobe is the most common.
幕上毛细胞型星形细胞瘤相对少见,囊壁多有强化。
pilocytic astrocytoma on curtain is relatively rare, cystic wall has aggrandizement more.
少突胶质细胞瘤常伴有钙化,一般肿瘤较大,边缘不清,可能会造成颅骨的改变。
Oligodendroglioma is often accompanied by calcification. The tumor is usually large and has unclear margins, which may cause changes in the skull.
幕上血管母细胞瘤典型表现为囊性病灶伴壁结节形成,但在MRI上可见血管流空信号。
Suprasentorial hemangioblastoma typically presents as a cystic lesion with a mural nodule, but there is a clear signal of empyreogenesis on MRI.
炎性肉芽肿壁结节少见,环形壁强化,可单发或多发,结节内部结构的信号多变。
Inflammatory granuloma wall nodules are rare, ring wall enhancement, single or multiple, the internal structure of the nodules signal variable.
