case_images: PMC5379809_01
case_images: Initial T1W magnetic resonance imaging (MRI): Left hemicerebral atrophy with diffuse sulcal widening and prominent left sylvian fissure without ventricular enlargement (a); T2W: Subtle hyperintense signal changes at the left globus pallidus and posterior limb of the internal capsule (b); DWI: Restricted diffusion of the same areas (white arrow, c) and GRE: Hypointense signals ("blooming") (black arrow, d); 2 years later: Large left basal ganglia cystic lesion (T2W with left cerebral peduncle atrophy, white thin arrow (e); T2W (f); contrast T1W (g); 6-month post-treatment contrast T1W MRI showed no recurrent tumor (h)
case_images: AJNS-12-65-g001.jpg
case_images: PMC5379809_01_AJNS-12-65-g001.jpg
case_images: F1
case_images: There were also subtle T2-weighted hyperintense signals at the left globus pallidus and the posterior limb of the left internal capsule [Figure 1a and b]. On DWI, there was evidence of restricted diffusion over the same region associated with susceptibility changes on GRE sequences suggesting a possible left basal ganglia tumor with previous microhemorrhage [Figure 1c and d]. Repeat imaging revealed a large cystic lesion arising from the left globus pallidus [Figure 1e-g]. At 6-month post-treatment, MRI scans showed complete disease remission [Figure 1h].
case_images: Photo-micrograph. H and E stain. Sheets of large pleomorphic tumor cells with enlarged nuclei, prominent nucleoli and vacuolated cytoplasm. Note hemosiderin deposition in the center (arrow head, a); Placental alkaline phosphatase reactive staining (b); and strong diffuse c-kit positivity characteristic of pure germinomas (c)
case_images: AJNS-12-65-g002.jpg
case_images: PMC5379809_01_AJNS-12-65-g002.jpg
case_images: F2
case_images: Craniotomy with near total excision was performed and histology revealed large pleomorphic cells with prominent nucleoli and reactive lymphocytic infiltrates [Figure 2a]. Immunohistochemistry identified the tumor cells to be positive for placental alkaline phosphatase (PLAP) and strongly reactive to membranous c-kit (CD117), a distinctive feature of pure germinomas [Figure 2b and c].