1、CASE REPORTCASE REPORTDysembryoplastiDysembryoplastic c NeuroepithelialNeuroepithelial TumorTumor(DNET)(DNET)胚胎发育不良性胚胎发育不良性神经上皮肿瘤神经上皮肿瘤北京大学人民医院北京大学人民医院 陈皓陈皓History M,17 yrs ID number:1186959 Intractable complex partil seizures for 10 yrs.Neurological examinations:no special companying neurologic def
2、icit.Radiological FindingsCTMRIT1WIT2WIFLAIRDWIT1WI GD-DTPAMRSRadiologic appearance CT：A well-demarcated introcortical hypoattenuating lesion with no edema and mass effect in the right frontal-parietal lobe.MRI：The lesion shows T1WI hypointense,T2WI hyperintense,FLAIR mixed isointense with a“bright”
3、rim,DWI isointense,T1WI CE no enhancement.No peritumoral edema and occupying effect.MRS：No obvious change of Cho and Cr,NAA reduces slightly.Final diagnosis Dysembryoplastic Neuroepithelial Tumor（DNET）胚胎发育不良性神经上皮瘤IntroductionConceptDysembryoplastic teuroepithelial tumor(DNET)A rare benign intracorti
4、cal supratentorial mixed neuronal-glial neoplasm.Most common located in the temporal lobe.First reported by Daumas-Duport,et al in 1988.Epidemical features Frequency:rare,1%of all primary brain tumors.Age:adolescents and young adults within 20 years old.Gender:MF.Pathology A:Hallmark:Specific glione
5、uronal element (SGNE)=Columns of heterogenerous cells located in a neurofibrillary matrix,including:oligodendrocyte-like cells+mature ganglion cells+astrocytes.B:Typical findings:Involvement of the cortical gray matter and a multinodular growth pattern.C:Accompanying findings:The cortex adjacent to
6、a DNET shows a disordered architecture.Left：shows the nodular growth pattern and the loose matrix of this tumor.Note the focal calcification(arrow).Right：shows many oligodendroglia-like cells with small round nuclei(arrow)and a clear perinuclear halo.These cells are located in a neurofibrillary matr
7、ix.Clinical features Partial chronic drug-resistant seizures occurred during early chilodhood.No accompanying neurologic deficits.Treatment and prognosis Drugs:to control seizures.Surgical treatment:operation to remove tumors and to cure seizures.Prognosis:free of seizures in 70-81%patients,and seld
8、om envidence of tumor recurrence and enlargement after surgery.Radiologic featuresCT:Well-demarcated introcortical hypoattenuating lesion.“pseudocystic”appearance.Minimal or subtle calcification.(Fig.1)No or focal contrast enhancement.(Fig.2)Fig.1 shows calcification in a well-demarcated introcortic
9、al hypoattenuating tumor.Fig.2 shows focal contrast enhancement.MRI:1.Shape of lesionMultinodular or septated“pseudocystic”appearance.(Fig.1,Fig.2)Well-demarcated,wedge-shaped bubbly configuration.Triangular pattern of distribution(triangular sign)-the tumor width that is maximal at the cortical lev
10、el and decreases toward brain ventricle,may be related to the radial glial fibers pathway.(Fig.3,Fig.4)Fig.1 shows the septated appearance.(arrow)Triangular sign:pic.B,tumor width that is maximal at the cortical level and decreases toward brain ventricle.2.Signal features T1WI:hypointense.T2WI:very
11、hyperintense,multinodular or septated signs.FLAIR:mixed hypo/isointense signal with“bright”rim(Fig.1c,Fig.4),no peritumoral edema.DWI:usually lacks restricted diffusion,hypointense.T1WI enhancement:no enhancement,or focal/ring enhangcement in some tumors.(Fig.2,Fig.3)3.Circumjacent features No perit
12、umoral edema.No occupying effect.Thick gyrus in some patients.4.MRS No obvious change of Cho and Cr.NAA reduces slightly.Lac shows sometimes.Diagnosis Clinical features:choronical Intractable seizure.Radiologic features.Pathological features.Differential diagnosis Low-grade astrocytoma（低级星形细胞瘤）Oligo
13、dendroglioma（少突胶质瘤）Ganglioglioma（神经节细胞胶质瘤）Pleomorphic xanthoastrocytoma（黄色星形 细胞瘤）Neuroepithelial cyst（神经上皮囊肿）Low-grade astrocytoma（低级星形细胞瘤）Occur between 2040 yrs old.Grow in deep white matter and extend along white matter tracts,cortical involvement is rare.Peritumoral edema and occupying effect.Oli
14、godendroglioma（少突胶质瘤）Often occur in adults.Calcification along the gyrus is often seen.Frontal lobe involvement is frequent.Grow in deep white matter,and invade into adjancent cortex.Bone erosion is sometimes found.Nodular configuration and triangular sign seldom occur.Contrast enhanced.Gangliogliom
15、a（神经节细胞胶质瘤）Calcification is common.Change of skull.Tumor margin is usually ill-defined.Cystic or cystic/solid component.Strong contrast enhancement.Occupying effect can be seen.Ganglioglioma(a)CT shows a calcified mass(arrows)of the posteriorright temporal lobe.(b)T1WI shows a heterogeneously hypoin
16、tense tumor with a high signal intensity(arrowheads),corresponds to the calcification seen at CT.(c)T2WI shows high signal intensity with peritumoral edema.(d)CE T1WI shows ringlike enhancementof the mass.abcdShows the thinning of the adjacent skull.(arrow)Pleomorphic xanthoastrocytoma（PXA 黄色星形细胞瘤）C
17、ortical and meningeal involvement.Enhancing nodule abuts pia,and“dural tail”sign.a：Contrast-enhanced CT image shows a heterogeneous mass of the right parietal region with both cyst-like and soft-tissue components and inner table remodeling in the adjacent calvaria.The mural nodule enhances homogeneo
18、usly andintensely.b：Axial PD-weightedMR image shows high signal intensity of the cyst-like area in relation to CSF and isointensity of the solid component in relation to gray matter.c：Contrastenhancedsagittal T1-weightedMR image shows intense enhancement of the soft-tissue portion of the mass and pe
19、ripheral enhancement of the cystlikearea.a Contrast-enhanced CT image shows a heterogeneous enhancing solid mass of the left frontal lobe with some cystic changes.A moderate amount of surrounding vasogenic edema is present.b Axial T2-weighted MR image shows isointensity of the solid mass in relation
20、 to gray matter,whereas the cystic portions are hyperintense.Some“fingers”of vasogenic edema surround the mass.c Contrast enhanced axial T1-weighted MR image shows intense enhancement ofthe solid mass with rim enhancement of the cystic margin1a CT shows solid tissue with the same density as the grey
21、 matter,in the left frontallobe adjacent to the falx.1b The lesion shows marked,homogeneous contrast enhancement.2a Axial T1-weighted image shows a slightly low-signal solid lesion that on a T2-weighted image.2b gives lower signal than the surrounding oedematous brain.2c Axial and 2d coronal contras
22、t enhancedT1-weighted images show marked,homogeneous enhancement that involves the meninges,with a“tail”.Neuroepithelial cyst（神经上皮囊肿）Nonenhancement single or complex cystic structure.No bright“rim”on FLAIR.Key Fact DNET:a benign,intracortical mass.Clinical:long-standing seizures in young people.Radi
23、ology:well-demarcated intracortical triangular septated mass.T1WI:hypointensity,T2WI:hyperintensity,FLAIR:bright rim,CE:no enhancement,Pathology:SGNE.Diagnosis:clinical+radiology+pathology.DDx:Low-grade astrocytoma,Oligodendroglioma,Ganglioglioma,Pleomorphic xanthoastrocytoma,Neuroepithelial cyst,et al.THANK YOU!
