Diagnosis
10
Table 2. Panel of Routine Immunohistochemical Markers
for the Evaluation of Suspected Anaplastic Thyroid
Cancer and Expected Results Compared to Other
Tumor Types
IHC marker DTC PDTC ATC MTC SCC Lymphoma
Pan-cytokeratins +++ +++ +++/− +++ +++ −
yroglobulin +++ +/− − − − −
yroid-transcription
factor 1
+++ +/− −/+ +/− − −
BRAF
V600E
+/− −/+ −/+ − − −
PAX8 +++ +++ +/− +/− −
+/−
a
Ki-67
b
<5% 5–30% >30% <20% >30% variable
Chromogranin − − − +++ − −
Calcitonin − − − +++/− − −
CEA − − − +++ − −
p53 −(rare+) −/+ +/− − +/− +/−
CD45, other lymphoid
markers
− − − − − +++
a
PAX8 antibodies can cross react with PAX5, which is expressed in lymphoid cells.
b
Percentage of nuclei positive for Ki-67.
+ indicates relative positive staining, − indicates negative staining, +/− indicates variable positivity.
