Legends
Figure 1: Series of head (axial T2-weighted turbo spin echo
sequences) and spine (sagittal post-gadolinium T1-weighted turbo echo
sequences) MR examinations. A 12 year-old male presented with a
lobulated neoplastic pineal mass (A1; arrow), biopsy-proven to be a yolk
sac tumour, approximately measuring 4 x 2.5 x 4 cm (ap tr cc/ob),
markedly vascularised but non-high-cellular, and containing a couple of
subcentimetric central cystic foci. This lesion compressed and distorted
the third ventricle causing moderate obstructive hydrocephalus and
exerted mass effect also onto the right dorsal medial thalamic nuclei
and onto the ipsilateral dorsal midbrain along its aqueduct. No
intracranial or spinal metastases at baseline (A2). Favourable response
to chemotherapy and radical VMAT therapy was achieved 7 months after
diagnosis with a minimal cystic residuum (B1; arrow) which has remained
stable over time (C1, D1; arrow). However, 23 months after end of
treatment a millimetric faintly enhancing leptomeningeal deposit
overlying the cord at the level of T10-11 (B2; circle) developed. This
resolved (C2) the following year, after completion of further
chemotherapy, autologous stem cell transplant, and craniospinal
irradiation and has not reoccurred (D2) to date, 5 years off treatment.
Figure 2: Yolk sac tumour from the second endoscopic biopsy.
(A) Vacuolated tumor cells forming Schiller-Duval body around a blood
vessel (haematoxylin and eosin). (B) Immunohistochemistry confirms focal
positivity with alpha-fetoprotein (AFP).