Thanks Bob, 

First, in answer to your question, both Decal and Decal Stat contain
Hcl. Second, I read John Kiernan's reply regarding Bis-Chloromethylether
and I respect it. Arguments can be made on both sides of the BCME issue.
I will admit that we have never verified if 10% NBF and a typical HCL
decalcifier actually do create BCME.  I will leave that experiment to
others.  We just chose to err on the side of caution here. BCME or not,
we still maintain that a good rinse (preferably in Deionized water )
both before and after decalcification will make a noticeable difference
in the quality of decalcified tissue.  Six minutes of rinse water is not
a large outlay of time or money to vastly improve the quality of your
specimens.  

Best Regards to all-

Cliff Berger
www.decal-bone.com


-----Original Message-----
From: RSRICHMOND@aol.com [mailto:RSRICHMOND@aol.com] 
Sent: Saturday, December 08, 2001 11:11 PM
To: histonet@pathology.swmed.edu
Subject: Re: Bone Marrow


Thanks, Cliff Berger at www.decal-bone.com for reminding us that >>Decal
is a 
registered trademark of Decal Chemical Corp.<< When I replied to this
query 
before, I was on the road and without my reference books.

As many readers of this list know, I'm an elderly pathologist who does
locum 
tenens work, and thus sees many different working hospital and private 
histopathology labs. 

Cliff's observation that >>the trouble with most decalcified tissue is
not 
the type of decalcifier used but the specimen handling before and after 
decalcification. Proper fixation is usually the most important factor in
good 
decalcified specimens<< is entirely correct. Let me add several
practical 
points to that.

If a piece of bone isn't thin enough to fixed overnight, it needs to be
cut 
down with a saw until it is thin enough. If a femoral head arrives over
the 
weekend, it needs to be slabbed on Monday, the slab fixed overnight, and

decalcification begun on Tuesday. If the pathologist objects to the
delay, he 
can come in over the weekend and slab the bone, and, if he comes in
twice, 
decalcify it also. (Dream on.)

Pathologists need saws, and what they want varies. Many pathology
services 
supporting orthopedic services no longer have a saw at all! I am
unwilling to 
use a Stryker oscillating saw (there's often one of these left over from
an 
otherwise forgotten autopsy kit) on a piece of loose bone with no clamp.
The 
old Satterlee amputation saw looks like something left over from the
Civil 
War, but it's a good saw for those of us who aren't comfortable with 
hand-hazardous power tools. Still better is a double-bladed saw made for
the 
purpose. Since the Satterlee saw is over $70 (from whatever Lipshaw is
called 
this week) and the specially-manufactured double-bladed saw about $500,
the 
pathologist can't have one in these days of Good Management, so I
routinely 
go to a hardware store and buy a five dollar hacksaw. 

Who is responsible for completing the decalcification, the pathologist
or the 
histotechnologist? This question needs to be settled for every specimen.
A 
couple of weeks ago I was working in a lab I'd never worked in before.
Got an 
important decalcification specimen - a curetted bone tumor - carefully
fixed 
and and put it into (the real thing, Cliff) Decal. The histotechnologist
- a 
pleasant elderly woman who had clearly never looked at a slide in her
life, 
and wasn't about to start at the behest of a wandering pathologist - put
the 
specimen away and never mentioned it to me again until I asked her about
it 
at the end of the week. It appeared that I was supposed to go get it off
the 
shelf and get it into a cassette. Bad slip-up, but the sort of thing one
is 
apt to fall into the first week on the job

Cliff adds: >>Second, decalcifiers that contain HCl (hydrochloric acid) 
should never, and we mean never, be mixed directly with formalin. The 
combination of HCl and formaldehyde causes an extremely carcinogenic
vapor 
known as bis-chloromethylether.<< Uh, Cliff, you left something out here
- do 
Decal and Decal-Stat contain hydrochloric acid? - I've heard the 
bis-chloromethylether story and I've also heard it's an urban legend.
John 
Kiernan, do you know the answer to this? I don't.

Histopathology laboratories are losing the skills needed to prepare and
cut 
ordinary calcified tissue. To keep them up, it's important for
pathologist 
and histotechnologist to insist on good preparation of ordinary junk
bone 
specimens - femoral heads from fractures are an important specimen to
focus 
on, since they're common, reasonably easy to prepare, and actually of
some 
clinical importance, since unsuspected pathologic fractures (fractures 
through deposits of metastatic cancer in the bone) are reasonably common
and 
are important to diagnose. 

A worthwhile reference likely to be on a pathologist's book shelf is in
one 
of the AFIP fascicles: Tumors of the Bones and Joints, AFIP Atlas of
Tumor 
Pathology Third series fascicle 8, by Robert E. Fechner and Stacey E.
Mills 
(Charlottesville VA), AFIP/UAREP 1992.

Bob Richmond 
Samurai Pathologist
Knoxville TN