My two cents worth:

Let it fix and process the next day.  Yes, there are ways you can speed it
up to improve turnaround time.  However, do realize the Herceptest is an
FDA-approved kit and any variation in routine NBF fixation and routine
paraffin processing might nullify the result.  Adding an additional 24-hours
to a specimen such as this, unless grossed as described by Dr. Richmond,
should be the rule and not the exception.

-Teri Johnson
Physicians Reference Laboratory