Immunohistochemical characterization of neoplastic cells of breast origin.
BACKGROUND
After skin cancer, breast cancer is the most common malignancy in women. Tumors of unknown origin account for 5-15% of malignant neoplasms, with 1.5% being breast cancer. An immunohistochemical panel with conventional and newer markers, such as mammaglobin, was selected for the detection of neoplastic cells of breast origin. The specific objectives are: 1) to determine the sensitivity and specificity of the panel, with a special emphasis on the inclusion of the mammaglobin marker, and 2) to compare immunohistochemistry performed on whole tissue sections and on tissue micro-array.


METHODS
Twenty-nine metastatic breast tumors were included and assumed as tumors of unknown origin. Other 48 biopsies of diverse tissues were selected and assumed as negative controls. Tissue Micro-Array was performed. Immunohistochemistry for mammaglobin, gross cystic disease fluid protein-15, estrogen receptor, progesterone receptor and cytokeratin 7 was done.


RESULTS
Mammaglobin positive staining was observed in 10/29 cases, in 13/29 cases for gross cystic disease fluid protein-15, in 20/29 cases for estrogen receptor, in 9/29 cases for progesterone receptor, and in 25/29 cases for cytokeratin 7. Among the negative controls, mammaglobin was positive in 2/48, and gross cystic disease fluid protein-15 in 4/48.


CONCLUSIONS
The inclusion of MAG antibody in the immunohistochemical panel for the detection of tumors of unknown origin contributed to the detection of metastasis of breast cancer. The diagnostic strategy with the highest positive predictive value (88%) included hormone receptors and mammaglobin in serial manner.
Centro de Educación Medica e Investigaciones Clínicas "Norberto Quirno" (CEMIC), Ciudad Autónoma de Buenos Aires, Argentina.
Mariadelasmercedes
M
Noriega
Fernando
F
Paesani
Florencia
F
Perazzo
Néstor
N
Lago
Hugo
H
Krupitzki
Silvana
S
Nieto
Alejandro
A
Garcia
Alejandra
A
Avagnina
Boris
B
Elsner
Valeria Cecilia
VC
Denninghoff
D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D001943:Breast Neoplasms / Q000737:chemistry* / Q000556:secondary; D002352:Carrier Proteins / Q000032:analysis; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D053552:Keratin-7 / Q000032:analysis; D026901:Membrane Transport Proteins; D009382:Neoplasms, Unknown Primary / Q000737:chemistry* / Q000473:pathology; D011237:Predictive Value of Tests; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D060765:Secretoglobins / Q000032:analysis; D012680:Sensitivity and Specificity; D046888:Tissue Array Analysis
D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D006023:Glycoproteins; C507497:KRT7 protein, human; D053552:Keratin-7; D026901:Membrane Transport Proteins; C488892:PIP protein, human; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D060765:Secretoglobins