Baseline characteristics/demographics
Fifty-five children (52 from Royal Marsden Hospital and 3 from San
Raffaele Hospital) were included. The characteristics of the study
population are detailed in Table 1 . The median age at tumour
diagnosis was 12 (IQR 9–16) years, with a peak age between 9 and 10
years. Adolescents aged >11years accounted for 60% of
cases. Most patients were boys (67.3%) and prepubertal at the time of
diagnosis (54.5%).
Germinomas comprised most diagnoses (63.6% of the cohort). Children
<5 years old (n=2) were diagnosed with teratoma, whilst
germinoma occurred more frequently in older patients (p=0.052),
especially in the 11-18 age group (n=24, 75%). Seven biopsies reported
mixed GCT, all with a germinoma component.
Regarding the distribution of histology according to tumour locations,
germinomas were significantly dominant in the suprasellar region
(82.5%, p=0.047); together, NGGCTs accounted for 57.9% of the pineal
tumours. Teratomas were also found in suprasellar region (n=3) and in
atypical sites (n=2, right cerebro-pontine angle and thalamus). Seven
cases occurred bifocally (7/55, 12.7%); among them, five were
germinomas and two did not receive a histopathological diagnosis.
Six tumours were metastatic at diagnosis (10.9%), of which 4/6 were
germinomas.
Serum AFP and beta-HCG were available for 53/55 (96.4%) and 52/55
(94.5%) subjects, respectively (Table 1) . For cytological
detection of microdissemination, sampling of CSF was obtained; however,
data on CSF tumour markers were missing for 6/55 subjects. Of the 4
tumours with severely elevated serum HCG, one case was teratoma and the
remaining 3 cases had a mixed histology. Similarly, serum AFP was
severely raised only in NGGCTs (2 yolk sac tumour, 1 teratoma and 1
mixed histology). On the contrary, normal levels of serum AFP and HCG
were reported in 41 cases and 39 cases, respectively; they were all
germinomas, aside from one teratoma that showed normal serum HCG levels
and moderate elevation of both CSF HCG and AFP. PLAP results on biopsy
samples prior to treatments were available in 30/55 cases (54.4%) and
all of those that showed a positive PLAP staining were then diagnosed
with germinoma, except for one (mixed histology with a predominant yolk
sac component).