Glypican 3 has a higher sensitivity than alpha-fetoprotein for testicular and ovarian yolk sac tumour: immunohistochemical investigation with analysis of histological growth patterns.
OBJECTIVE
Glypican 3 (GPC3) has been reported to be overexpressed in yolk sac tumour (YST), but the sensitivity has not been compared with alpha-fetoprotein (AFP). YST can form numerous growth patterns and the expression of GPC3 in these patterns has not been studied. The aim was to address these aspects.


RESULTS
Sections from testicular or ovarian YST were subjected to immunohistochemistry using GPC3 (n = 39) and AFP (n = 24). Overall immunoreactivity for each case and specific histological patterns were semiquantitatively evaluated (0-3+) and intensity of reactivity was scored (0-3). All cases expressed GPC3 (1+, 5%; 2+, 8%; 3+, 87%) with strong intensity (2.9). The majority expressed AFP (58%) but immunoreactivity was often focal (0, 42%; 1+, 33%; 2+, 25%) and intensity was low (1.0). Using GPC3, >75% of the microcystic (n = 38), macrocystic (n = 26), solid (n = 21), glandular-alveolar (n = 8), endodermal sinus (n = 7), polyvesicular vitelline (n = 5), enteric (n = 4) and micropapillary (n = 2) growth patterns displayed 2+ or 3+ positivity.


CONCLUSIONS
YST can display a variety of growth patterns that can be confused with other germ cell tumour components. GPC3 detects all growth patterns tested and has a higher sensitivity for detecting YST than AFP.
Zynger
Debra L
DL
Department of Pathology, The Ohio State University Medical Center, Columbus, OH, USA.
McCallum
John C
JC
Luan
Chunyan
C
Chou
Pauline M
PM
Yang
Ximing J
XJ
D018240:Endodermal Sinus Tumor / Q000378:metabolism / Q000473:pathology*; D005260:Female; D053673:Glypicans / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology*; D012680:Sensitivity and Specificity; D013736:Testicular Neoplasms / Q000378:metabolism / Q000473:pathology*; D013737:Testis / Q000378:metabolism / Q000473:pathology; D000509:alpha-Fetoproteins / Q000378:metabolism*
D053673:Glypicans; D000509:alpha-Fetoproteins