[Histonet] Re: Inking Skin

[Bob Richmond]

Christie Gowan at UAB Hospital. Birmingham, Alabama asks:

>>My derm pathologist has requested that we ink the epithelium on MOHs derm cases (new pathologist). We process many derm specimens a day but it seems we are having trouble getting full epithelium on our cases that come over from the MOHs clinic. I am not sure that inking the skin will help with the problem but let's just say that if we do decide to ink the surface of these specimens, does anyone know of an ink that will actually stick to skin?

Your new pathologist should be able to specify what he wants. About
time they started teaching pathology residents where slides come from.

Mohs is somebody's name, not an acronym. Specifically Frederic Mohs,
an American surgeon (1910-2002):
http://en.wikipedia.org/wiki/Frederic_E._Mohs

You need a particulate ink that will stick to the specimen, withstand
frozen section or paraffin processing, and be visible on the slide.

Particulate marking inks for surgical pathology are made by a variety
of manufacturers. I prefer the Davidson marking inks, but there are
several other brands. They come in at least seven colors. A wooden
case that keeps the tall narrow bottles from tipping over is usually
included.

Tattoo inks are cheap and come in an almost unlimited variety of
colors, and in the one lab I've used them in work extremely well. The
downside is you have to read some pretty appalling catalogs if you
don't like tattoos and piercings (gimme a break, I'm 73 years old.)

You can get ordinary India ink (which by definition is black) very
easily. I didn't know that craft stores like Hobby Lobby offer a
variety of colored particulate inks - I'd want to know exactly what to
buy, to make sure I got a suitable colored ink that would show up on
the slide.

All of these inks have a good shelf life if you keep them tightly
capped except when you're actually using them. If they become
excessively viscous or solidify, they need to be thrown out.

The specimen must be blotted thoroughly dry before inking, and the ink
blotted off afterwards. If you do this you won't need to use anything
to "set" the ink. I never use these fixatives. If you do want to use
such a fixing solution, 2 or 3% acetic acid (diluted from glacial
acetic acid) or half strength ordinary grocery store white vinegar is
supposed to work as well as anything. It's unnecessary to use Bouin's
fixative or acetone, both of which are serious hazmats.

Bob Richmond
Samurai Pathologist
Knoxville TN