Freiburg Neuropathology Case Conference: A Pineal Region Tumour in a Child

T2-weighted MR images show a cystic lesion located in the pineal region. The lesion displays a nodular component adherent to the wall of the cyst (Fig. 1a). The surrounding tissue shows an increase in signal intensity (Fig. 1b). Circulation of cerebrospinal fluid (CSF) is impaired because of obstruction of the aqueduct with clear distension of the lateral ventricles (not shown). After cisternotomy, CSF circulation is back to normal. On non-enhanced T1-weighted images the solid component of the lesion appears isointense when compared to the grey matter (Fig. 2a). The solid component of the lesion shows homogenous enhancement of Gadolinium (Fig. 2b–d). On non-enhanced computed tomography, the solid component of the lesion appeared hyperdense (Fig. 3). On follow-up images after an initial biopsy the lesion clearly increased in size (Fig. 4).