Case Report
A 12 year-old male, previously fit and well, presented with a 2-week history of headache, nausea, vomiting, ataxia and drowsiness. A head CT scan showed a homogenous enhancing lobulated lesion within the right thalamic/pineal region which extended inferiorly to the right midbrain. The head and spine magnetic resonance (MR) examination demonstrated a lobular mass which appeared to be extra-axial and in continuity with the pineal gland with no evidence of disease involvement of the spine (Figure 1). Testicular ultrasound was normal. Serum alpha-fetoprotein (AFP) was 1,832 ng/ml and serum beta-human chorionic gonadotropin (β-HCG) was 16 IU/L. Cerebrospinal fluid (CSF) cytology did not show any malignant cells and AFP in CSF was 34.9 ng/ml (β-HCG not available).
The child underwent endoscopic third ventriculostomy, stereotactic biopsy of the posterior third ventricular lesion, and insertion of a Rickham reservoir. The initial biopsy was inconclusive. A second biopsy was obtained together with insertion of an external ventricular drain, which was later replaced by a ventriculo-peritoneal shunt. The second biopsy showed a malignant GCT with predominant features of YST (Figure 2). Immunohistochemistry confirmed focal positivity with AFP, pan-cytokeratin and in occasional cells with HCG. PLAP, synaptophysin and GFAP were negative while INI1 (BAF47) was normally expressed in the tumour cells. The tumour showed high proliferation index (Ki67: 70%).
The child was treated as per SIOP CNS GCT 96 protocol off-trial with 4 cycles of cisplatin, etoposide and ifosfamide (PEI). Following the 4th cycle of chemotherapy, MR assessment showed partial response according to Response Evaluation Criteria in Solid Tumors, version 1.114. Serum tumour markers also normalized. Subsequently, he received radical volumetric modulated arc therapy (VMAT) to the residual tumour (54 Gy in 30 fractions) with a single arc VMAT plan. Following that, MR brain scan revealed a stable subcentimetre tumour residuum with negative serum tumour markers.
Two years after the end of treatment, routine serum tumour markers showed AFP 56.6 ng/ml with β-HCG <2 IU/L. MR brain and spine demonstrated stable intracranial disease, with a new solitary plaque of enhancing tissue over the surface of the spinal cord posteriorly on the left side at the level of T10 disc space (Figure 1). The child received alternating carboplatin/etoposide and ifosfamide/etoposide for a total of 4 cycles as per SIOP CNS GCT II trial (NCT01424839). After 4 cycles of chemotherapy, shrinkage of the T10 meningeal spinal metastasis was seen on MRI; serum AFP was 4.8 ng/ml. He then received high dose thiotepa and etoposide followed by autologous stem cell transplant (ASCT). Finally, he received craniospinal irradiation CSI (30 Gy in 16 fractions) with a boost to the site of recurrence at T10 (20.8 Gy in 13 fractions).
The end of treatment MRI showed maintained response and serum AFP was normal. This young man is currently alive, with normal serum tumour markers and no evidence of further recurrence 5 years after completion of treatment.