Placental site trophoblastic tumor: human placental lactogen and pregnancy-associated major basic protein as immunohistologic markers.
Placental site trophoblastic tumor (PSTT) consists of a neoplastic proliferation of intermediate or extravillous trophoblast (also known as X cells). Pregnancy-associated major basic protein (pMBP) is a marker for placental intermediate trophoblast. We compared the distribution of pMBP and human placental lactogen (hPL) in 24 PSTT and 3 exaggerated placental site (EPS) specimens using two distinct immunohistologic methods. Statistical analyses were used to compare staining intensities in metastatic and nonmetastatic lesions. By immunofluorescence, 77% of the PSTT specimens and 100% of the EPS specimens stained with antibodies to pMBP, and the pMBP was localized in intermediate trophoblast and surrounding extracellular areas. By immunohistochemistry, 78% of the PSTT specimens and 100% of the EPS specimens stained for pMBP with a pattern comparable with that of immunofluorescence. Likewise, by immunohistochemistry, hPL stained 96% of the PSTT specimens and 100% of the EPS specimens. Immunohistochemical staining intensities for pMBP and hPL correlated (r2 = +.24; P = .013), but hPL staining was mainly confined to intermediate trophoblast and was more intense. Anti-pMBP tended to stain metastatic PSTT weakly. Thus, pMBP is a useful marker for intermediate trophoblast tumors and could help distinguish these from other forms of trophoblastic disease.
Rhoton-Vlasak
A
A
Department of Immunology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
Wagner
J M
JM
Rutgers
J L
JL
Baergen
R N
RN
Young
R H
RH
Roche
P C
PC
Plummer
T B
TB
Gleich
G J
GJ
D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D010928:Placental Lactogen / Q000378:metabolism*; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000378:metabolism* / Q000473:pathology; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D018245:Trophoblastic Tumor, Placental Site / Q000378:metabolism* / Q000473:pathology / Q000556:secondary; D014594:Uterine Neoplasms / Q000378:metabolism* / Q000473:pathology
D014408:Biomarkers, Tumor; D010928:Placental Lactogen; D011266:Pregnancy-Associated Plasma Protein-A