[Histonet] Processing artefact??

[Greg Dobbin]

Hello experts,
Every now and then we will get stained slides that look like the attached
image. We run one processing schedule (about 11 hrs) for everything so yes,
our smaller biopsies are somewhat overprocessed, but 90-95% of the time
they look perfectly fine. We can have GI biopsies in a case that go from A
to P and find only one that looks like this. Moreover, recuts do not
remedy the problem either...the problem seems to be occurring prior to
microtomy.

We use vendor grade Xylenes in our processor (a Leica ASP6025). All
specimens are fixed for 18-24 hours prior to processing. Our GI blocks get
a short soak in phenol prior to microtomy to help with the effects of
overprocessing. All blocks within a case are treated the same. In fact we
have also seen it in skin biopsies occasionally and skins do not get soaked
in phenol.

It is the randomness of the problem that is throwing us!
Any ideas?
Thanks,
*Greg Dobbin*

Chief Technologist
Anatomic Pathology
Queen Elizabeth Hospital
Charlottetown, PE, Canada