Article Figures & Data
Figures
- Fig 1.
Images of a 58-year-old man (patient 5) with resection-proved PNET.
A, Contrast-enhanced axial view T1-weighted image (600/14/1) shows a fairly well-defined enhancing mass in the right frontal region. Approximately 70% of the lesion enhanced. Cystic/necrotic components can be seen in the lesion.
B, Axial view T2-weighted image (3400/119/1) shows some areas of hypointensity within the mass, with a small amount of peritumoral edema and mass effect.
C, Gradient-echo axial view perfusion MR image (1000/54) and rCBV color overlay map show increased perfusion with a high rCBV of 6.98 and vascular permeability (Ktrans) of 0.00017 s−1.
- Fig 2.
Images of a 34-year-old woman (patient 11) with biopsy-proved PNET.
A, Contrast-enhanced axial view T1-weighted image (600/14/1) shows a peripherally enhancing mass in the genu of the corpus callosum. Approximately 50% of the lesion enhanced. Cystic/necrotic components can be seen in the lesion.
B, Axial view T2-weighted image (3400/119/1) shows some areas of hypointensity within the mass, indicating the increased cellularity of these tumors, with a significant amount of peritumoral edema and mass effect. The signal intensity characteristics and involvement of the corpus callosum would raise the possibility of lymphoma as a differential diagnosis.
C, Gradient-echo axial view perfusion MR image (1000/54) and rCBV color overlay map show increased perfusion with a high rCBV of 6.82 and vascular permeability (Ktrans) of 0.00034 s−1. Lymphoma would appear as reduced perfusion.
- Fig 3.
Images of a 52-year-old woman with a histologically confirmed grade II/IV glioma (A−C) and a 70-year-old woman with a histologically confirmed grade III/IV glioma (D−F).
A, Contrast-enhanced axial view T1-weighted image shows a lesion in the right temporoparietal region with low signal intensity and minimal enhancement.
B, Axial view T2-weighted image shows increase in T2 signal intensity within the lesion, with minimal edema.
C, Gradient-echo axial view perfusion MR image and rCBV color overlay map show a low rCBV of 1.70, in keeping with a low grade glioma. A thin rim of minimally increased perfusion can be seen at the margin of the lesion. This is compared with the increased rCBV of PNETs shown in Figures 1C and 2C.
D, Contrast-enhanced axial view T1-weighted image shows a lesion in the right thalamic region with heterogeneous peripheral contrast enhancement and a central cystic/necrotic region.
E, Axial view T2-weighted image shows increase in T2 signal intensity within the lesion with moderate surrounding edema. The patient also has hydrocephalus and transependymal edema around the ventricles.
F, Gradient-echo axial view perfusion MR image and rCBV color overlay map show a high rCBV of 3.70, in keeping with a high grade glioma. A thick rind of marked increased perfusion cannot be readily differentiated from the increased rCBV of PNETs shown in Figures 1C and 2C.
- Fig 4.
Photomicrographs of PNETs.
A, Hematoxylin and eosin stain shows a hypercellular neoplasm. Poorly differentiated, primitive small cells growing in compact sheets, forming a characteristic Homer-Wright rosette (R), can be seen. Tumor cells have round to oval hyperchromatic nuclei with scant cytoplasm. Mitotic figures are also identified (arrow). The increased cellularity explains iso- or hypointensity of many of the lesions on T2-weighted images (original magnification, ×200).
B, Hematoxylin and eosin stain shows increased vascular channels (arrows) in PNET (original magnification, ×50).
C, Hematoxylin and eosin stain at higher power shows endothelial hyperplasia (arrows) (original magnification, ×400).
D, Azocarmine stain highlights the vascular channels and shows proliferation and thickening of the vascular endothelium within the PNET (original magnification, ×100).
Tables
Patient No. Volume (cm3) T1 Signal T2 Signal Enhancement* (%) Edema Mass Effect Necrotic/Cystic Lesion Delineation Heterogeneity Calcification 1 5 × 3 × 2.5 Iso Iso 50 + + Yes Well Yes Yes 2 2.5 × 2 × 2 Iso Hypo 90 − + Yes Well Yes No 3 6 × 6 × 6 Hypo Iso 30 ++ +++ Yes Well Yes No 4 6 × 6 × 6 Hypo Iso 80 + ++ Yes Well Yes No 5 3.5 × 2.5 × 1.5 Iso Hyper 70 ++ + Yes Well Yes No 6 3.5 × 4 × 3 Hypo Hyper 50 + ++ Yes Ill Yes Yes 7 5 × 3 × 2 Iso Iso 50 + + Yes Ill Yes No 8 2.5 × 1.5 × 2 Iso Hyper 80 − − No Well No No 9 3 × 3 × 3 Iso Hyper 90 + + No Well Yes No 10 7 × 6 × 5 Iso Iso 30 ++ +++ Yes Well Yes Yes 11 1.5 × 2 × 2 Iso Hypo 50 +++ + Yes Well Yes No 12 1 × 1 × 1 Iso Hypo 50 − − No Well No No Note.—Iso indicates isointense to gray matter; Hypo, hypointense; Hyper, hyperintense; +, mild; ++, moderate; +++, severe.
* Enhancement is shown as the percentage of the lesion volume that enhanced.
- TABLE 2:
Relative cerebral blood volume measurements and vascular permeability measurements in patients with primitive neuroectodermal tumors
Patient No. Age (y)/Sex Location rCBV SD Ktrans SD 1 28/M Temp/brain stem/cerebellum 8.90 3.00 × 10−04 2 37/F Thalamus/brain stem 3.33 5.70 × 10−03 3 42/M Right frontal 4.28 9.20 × 10−03 4 68/M Bifrontal 3.97 1.20 × 10−03 5 58/M Right frontal 6.98 1.70 × 10−04 6 52/M Right frontal 4.34 4.80 × 10−05 7 46/M Right temporal 5.43 8.40 × 10−03 8 46/F Pineal 5.11 5.20 × 10−03 9 83/F Left parietal 2.72 5.90 × 10−04 10 42/M Temporoparietal 2.28 3.35 × 10−05 11 34/F Bifrontal 6.82 3.40 × 10−04 12 22/M Suprasellar 2.91 2.00 × 10−03 Mean 46.50 4.76 1.99 0.0033 0.0035 Note.—M indicates male; F, female; Temp, temporal; rCBV, relative cerebral blood volume; Ktrans, vascular permeability (s−1).
- TABLE 3:
Comparison of relative cerebral blood volume and vascular permeability measurements in patients with primitive neuroectodermal tumors with low grade gliomas (grade II/IV) and high grade gliomas (grade III/IV and IV/V)
Tumor Type rCBV SD Ktrans SD PNET (n = 12) 4.76 1.99 0.0033 0.0035 Low grade glioma (n = 30) 2.14 1.67 0.0005 0.001 P value <.0005 <.05 High grade glioma (n = 55) 5.82 3.57 0.0016 0.003 P value 0.53 0.19 Note.—rCBV indicates relative cerebral blood volume; Ktrans, vascular permeability (s−1); PNET, primitive neuroectodermal tumor.
