15 Minutes Immunohistochemistry Tutorial
1. Nonepithelial tumors expressing keratin
c. Synovial sarcoma
d. Epithelioid sarcoma
f. Some smooth muscle tumors
g. Rare melanomas, esthesioneuroblastomas, desmoplastic round cell tumors
B. Epithelial Membrane Antigen (EMA)
C. Carcinoembryonic Antigen (CEA)
D. Leu M1 (CD15)
F. Thyroid Transcription Factor (TTF-1)-nuclear
H. GCDFP-15 (gross cystic disease fluid protein-15)
Soft Tissue Tumor Markers
A. Intermediate Filaments
a. Present in most mesenchymal tumors, including lymphomas, melanomas.
b. Ideal tissue control for immune reactivity.
c. May be expressed by some carcinomas (renal, lung).
a) Most muscle tumors although may be negative up to 50% of leiomyosarcomas
b) Skeletal, cardiac, and smooth muscle are positive
B. Myoid markers
1. Muscle-specific actin (MSA)
HHF-35 positive in skeletal, smooth and cardiac muscle and is most
sensitive marker to identify muscle differentiation.
b. Some lymphomas and myofibroblastic lesions will stain.
2. Smooth muscle actin (SMA)
a. Not specific to smooth muscle, but useful and very sensitive.
a. Most specific but not very sensitive.
b. Most often positive in rhabdoid differentiation.
C. Endothelial markers
1. Factor VIII
a. Very specific though not highly sensitive without trypsinization
b. May be negative to poorly differentiated angiosarcomas.
a. Most sensitive endothelial marker, platelets
b. Complete specificity
3. Ulex lectin
a. Useful, but positive in some carcinomas and epithelioid sarcoma
a. Best for endothelial cells of Kaposi's sarcoma
Positive in solitary fibrous tumor and DFSP
protuberans, GI stromal tumors, hemangiopericytomas, hematopoietic precursor
CK7/CK20 Immunophenotype of Various Epithelial Tumors
CK7+ CK20 +Transitional Cell carcinoma
Ovarian Mucinous Carcinoma
CK7+ CK20 -Non-Small Cell Adenocarcinoma of Lung
Bronchoalveolar Carcinoma of Lung
Breast Carcinoma, Ductal and Lobular Types
Ovarian Carcinoma Other than Mucinous CA Endometrial carcinoma
CK7 - CK20 +Colorectal Carcinoma
Merckel Cell carcinoma
CK7 - CK20 -Hepatocellular Carcinoma
Renal cell carcinoma
Squamous Cell carcinoma of Lung
Small cell Neuroendocrine CA of Lung