Unusual appearance and presentation of supratentorial subependymoma in an adult patient

Abstract

We report a case of a large, heterogeneously enhancing, pathologically proven, supratentorial subependymoma in a 31-year-old male patient presenting with headache, nausea and vomiting as well as gait disturbances. Although most supratentorial subependymomas have distinctive MR features, our case demonstrated imaging findings that made it indistinguishable from other more aggressive malignant supratentorial intraventricular lesions. It is of paramount importance to consider supratentorial subependymomas in the differential diagnosis of supratentorial lesions, even if their radiological features were atypical.

Keywords: MRI; adult; intraventricular; subependymoma; supratentorial; tumor.

Figure 1

31 year old male with subependymoma. MRI Axial FLAIR image showing heterogeneous, hyperintense lesion in the left lateral ventricle (arrow), with moderate bilateral lateral ventricular hydrocephalus. Note the tiny signal void vessels in the lesion indicating high vascularity (arrowhead). MRI: 1.5 Tesla magnet, FLAIR (TE = 8000, TR = 147), axial, 5 mm slice.

Figure 2

31 year old male with subependymoma. MRI coronal T2-weighted image showing heterogeneous T2 hyperintense lesion in the left lateral ventricle extending into the third ventricle causing supratentorial hydrocephalus (arrow). Hyperintense cystic areas (small arrow) are also seen in the lesion. Note linear signal void vessel denoting high vascularity of the lesion (arrowhead). MRI: 1.5 Tesla magnet, T2 (TE 5000, TR 87), coronal, 5mm slice.

Figure 3

31 year old male with subependymoma. MRI axial post-contrast T1-weighted image demonstrating heterogeneous enhancement of the lesion (arrow). MRI: 1.5 Tesla magnet, T1 with contrast (TE = 466, TR = 9), axial, gadolinium (Prohance), 15 ml.

Figure 4

31 year old male with subependymoma. MRI Axial T1 image showing large posterior left lateral ventricular diverticulum projecting medially and inferiorly into the quadrigeminal cistern, producing mass effect on the tectum and vermis (arrow). MRI: 1.5 Tesla magnet, T1 (TE =, TR =), axial, 5 mm slice.

Figure 5

31 year old male with subependymoma. MRI Diffusion weighted sequence. (a) DWI image shows focal areas of hyperintensity (arrow). (b) ADC map shows areas of low ADC values (arrow) corresponding to areas of DWI hyperintensity suggesting moderately hypercellular tumor. MRI: 1.5 Tesla magnet, DWI (TE = 110, TR = 12000, b=1000), ADC map, axial, 5mm slice.

Figure 6

31 year old male with subependymoma. MRI contrast enhanced dynamic susceptibility contrast perfusion image reveals multiple foci of high CBV (arrow) within the tumor. MRI: 1.5 Tesla magnet, axial GRE EPI (TE = 40, TR = 2262).

Figure 7

31 year old male with subependymoma. Histomorphological examination of the tumor with Hematoxylin and eosin stain demonstrates clusters of round relatively monomorphous cells, supported by a fibrillary background and exhibiting discrete cytoplasmic borders. (original magnification ×60).

Figure 8

31 year old male with subependymoma. Histopathology with Hematoxylin and eosin stain. The tumor also demonstrated vascular proliferation and necrosis. Sclerotic vessel changes were also focally appreciated (original magnification ×40).

Figure 9

31 year old male with subependymoma. Histopathology with Immunoperoxidase staining for MIB-1. Immunohistochemistry staining of subependymoma with MIB-1 proliferative marker demonstrated positive labeling of approximately 0.8% of tumor cells (original magnification × 20).