• All IHC stains will include a positive control tissue

• Among hepatomas 10-70% have been reported as positive in most series. Among positive cases, the frequency of individual AFP-positive cells varies from 5-50% or more.
• AFP positivity has also been reported in hepatoblastomas of childhood.

• Primary cholangiocarcinoma is AFP negative.

• Germ cell tumors:

• Endodermal sinus tumors are usually positive for AFP.

• Some embryonal carcinomas and teratomatous epithelium are also positive for AFP.

• Seminomas/dysgerminomas, intratubular germ cell neoplasia and choriocarcinomas are negative for AFP.

• Bladder tumors may occasionally produce AFP (especially if they are of urachal origin).

Tissue Localization of Alpha-Fetoprotein in Malignant Germ Cell Tumors

Submit a formalin-fixed, paraffin embedded tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

Tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• Alpha-fetoprotein is a 64kD tumor-associated embryonal antigen synthesized during fetal life in the yolk sac, liver and gastrointestinal tract and produced by liver, yolk sac and some germ cell tumors of testicular and ovarian origin.

 Staining patterns

• Cytoplasmic based staining