The intestinal-type mucinous glands were immunoreactive for SALL4 (4 cases), AFP (4 cases), glypican 3 (1 case), CDX2 (6 cases), and villin (7 cases), markers that are commonly expressed in YSTs, although the latter 2 markers would be expected to be positive in intestinal-type glands.
CDX2 positivity in other tumours (one pure yolk sac tumour, one yolk sac component of a mixed GCT and one pure seminoma) was infrequent, and was only weak and focal.