Immunohistochemical type distinction of alpha-fetoprotein in various alpha-fetoprotein-secreting tumors

Carcinoma of the stomach with hepatocyte differentiation (hepatoid adenocarcinoma)

A case of hepatoid adenocarcinoma of the stomach is reported, and the literature is reviewed. The stomach is one of the most common sites in which hepatoid adenocarcinomas have been detected. Of the 59 cases reviewed from the literature (including the current case), a 2:1 male predominance was noted, and the serum alpha-fetoprotein level was almost always increased. All patients were adults, and most had evidence of metastases at the time of resection. Prognosis seems less favorable than that associated with the more common intestinal type of adenocarcinoma of the stomach. Hepatoid adenocarcinomas typically show periodic acid-Schiff-positive, diastase-resistant intracytoplasmic globules, which are demonstrated to be positive with antibodies to alpha-fetoprotein. The tumor cells resemble liver cells, and rare cases, including our own, have evidence of bile production. In our case, messenger RNA for albumin, unique to liver cells, was demonstrated by in situ hybridization of the tumor cells.

Alpha-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 19-9-producing gallbladder cancer

We report a rare case of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19-9-producing gallbladder cancer with high levels of CA125 and protein induced by vitamin K absence or antagonist II (PIVKA II). A 63-year-old man was diagnosed with gallbladder cancer with metastases to the liver, based on ultrasonography and computed tomography of the abdomen showing multiple tumorous lesions in the liver and a thickened gallbladder wall. Laboratory data showed high levels of tumor markers: 4647.4 ng/ml AFP, 9987.1 ng/ml CEA, 11,704.0 U/ml CA19-9, 847.6 U/ml CA125, and 0.2 AU/ ml PIVKA II. AFP in the present case showed an increase in Concanavalin A-nonbinding fraction and an increase in Lens culinaris lectin-binding fraction by affinity column chromatography. The patient died of hepatic failure. Autopsy revealed gallbladder cancer consisting of papillary adenocarcinoma and moderately differentiated tubular adenocarcinoma. By immunohistochemical staining, AFP was detected in the papillary adenocarcinoma portion of the primary focus and metastatic tumor cells in the liver, but was not detected in noncancerous liver tissue. CEA and CA19-9 were detected mainly in the tubular adenocarcinoma portion.

Immunohistochemical characterization of undifferentiated carcinomas of the ovary

Immunohistochemical characteristics of undifferentiated carcinomas of the ovary were examined using formalin-fixed, paraffin-embedded tissues with an avidin-biotin staining approach. Eight cases were collected from the pathology files of our Institute from a total of 214 recorded malignant ovarian tumors. For immunostaining, antibodies reacting with epithelial membrane antigen (EMA), pankeratin, vimentin, CA 125, CA 19-9, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), alpha-1-antitrypsin (AT), epidermal growth factor receptor (EGFR), c-erbB-2, bcl-2 and p53 proteins were used. All the cases examined were positive for EMA and pankeratin, specific markers for epithelial tumors, negative for the non-epithelial tumor marker, vimentin, and also positive for EGFR. Interestingly, only one case was positive for CA 125, despite it being one of the commonest reported indicators of ovarian cancer. CA 19-9 was positive in 7 cases, CEA in 5, AFP in 2, AT in 6 and c-erbB-2 protein in 4. Two cases were positive for p53 protein, and in 1 of these positive staining for bcl-2 was also observed. These results indicate that the epithelial nature is well preserved in undifferentiated ovarian carcinomas, although consistently positive reactions were not observed within the cases for some antigens. They further clearly show that a negative signal for CA 125 can not be considered to exclude the possibility of a primary ovarian tumor.