[Histonet] Minimum sample size for breast markers

[Martha Ward-Pathology]

Is there a minimum number of cells that should be present when testing for ER, PR and Her2? I have looked on the CAP website but cannot see anything about this.  We are constantly getting these small biopsies or FNAs for testing and I sometimes wonder what the lowest threshold is for testing...20 tumor cells, 50 tumor cells????   Any information would be appreciated.   Thanks in advance for your help.
 
Martha Ward, MT (ASCP) QIHC
Manager

Molecular Diagnostics Lab
Medical Center Boulevard  \  Winston-Salem, NC 27157
p 336.716.2109  \  f 336.716.5890  
mward <@t> wakehealth.edu