CMID Practice Test

Immunohistochemical profiling uses markers that highlight different germ cell tumor components. CD30 is the classic marker for embryonal carcinoma, while glypican-3 is frequently expressed in yolk sac tumors. Seeing CD30 positivity points toward embryonal carcinoma, and glypican-3 positivity supports a yolk sac–type component; together they are commonly used to characterize germ cell tumors. In contrast, CK7 and claudin-4 are general epithelial markers and not specific for germ cell tumors, and calretinin with inhibin are markers more typical of sex cord–stromal tumors rather than germ cell tumors. Thus, glypican-3 paired with CD30 best reflects germ cell marker usage.