Tumor markers Flashcards
Vementin positive on immunohistochemistry
Mesenchymal tumor
Desmin positive on immunohistochemistry
Muscle tumor
GFAP positive on immunohistochemistry
Neuroglial tumor
Chromagranin positive on immunohistochemistry
Neuroendocrine tumor (i.e. carcinoid tumor or small cell lung carcinoma)
S-100 positive on immunohistochemistry
Melanoma, schwannoma, or langerhans cell histiocytosis
TdT
Lymphoblast marker. DNA polymerase present in the nucleus of lymphoblasts. Not seen in myeloblasts or in mature lymphocytes. Marker for ALL
Myeloperoxidase
Myeloblast marker. Can crystallize to form Auer rods. Marker for AML, but often absent in acute monocytic leukemia and acute megakaryoblastic leukemia
B-ALL surface markers
TdT, CD10, CD19, CD20
T-ALL surface markers
TdT, CD2 through CD8. No CD10
Translocations in B-ALL
t(12;21): seen in kids; good prognosis
t(9;22) seen in adults; poor prognosis
t(15;17)
Seen in APML. Translocation of retinoic acid receptor on chromosome 17 to chromosome 15. RAR disruption blocks maturation so promyelocyte blasts accumulate.
CD34
Marker of hematopoeitic stem cell
CLL markers
CD5 and CD20
TRAP
Positive in hairy cell leukemia
Leukocyte alkaline phosphatase
Enzyme present in secondary granules of granulocytes. Negative in CML; positive in infection induced granulocytosis - useful for distinguishing.