Carcinoembryonic antigen and nonspecific cross-reacting antigen in medullary carcinoma of the thyroid.
Carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) were studied immunohistochemically in formalin-fixed, paraffin-embedded tissues of 73 cases of medullary carcinoma of the thyroid (MTC) using 2 polyclonal antibodies (CEA antisera cross-reactive with or without NCA), 3 monoclonal antibodies recognizing epitopes only on CEA, and one monoclonal antibody against NCA. The staining patterns of the 5 antibodies against CEA in MTCs were not different, and they reacted with 86.3% of all cases. With regard to the effects of fixatives on the staining patterns, samples fixed with formalin or 4% paraformaldehyde demonstrated CEA immunoreactivity in both the cell membrane and cytoplasm. In Bouin-fixed tissue, the immunoreactivity was predominant on the cell membrane, whereas cytoplasmic positivity predominated in alcohol-fixed specimens. Thus the difference in fixatives used in previous studies does not appear to be a major reason for the difference in the reported incidence of CEA-positive MTCs. It is concluded that CEA is still a useful tumor marker for MTC and that it is detectable only in thyroid tumors originating from C cells, as seen in our series. The epitope defined by monoclonal antibody F106-88, present only on NCA, was found in 42.5% of all cases (49.2% of CEA-positive MTCs). The NCA immunoreactivity was located in the tumor cell cytoplasm as globular aggregates, which were also labeled for CEA.
Kakudo
K
K
Department of Pathology, Tokai University School of Medicine, Isehara, Japan.
Takami
H
H
Katayama
S
S
Matsuura
N
N
Kamoshida
S
S
Miyauchi
A
A
Watanabe
K
K
D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D000951:Antigens, Neoplasm; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D002277:Carcinoma / Q000276:immunology* / Q000473:pathology; D015815:Cell Adhesion Molecules; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D013964:Thyroid Neoplasms / Q000276:immunology* / Q000473:pathology
D015214:Antigens, Differentiation, Myelomonocytic; D000951:Antigens, Neoplasm; D002272:Carcinoembryonic Antigen; D015815:Cell Adhesion Molecules; D006023:Glycoproteins