[Histonet] staining of anterior pituitary?

[Lee & Peggy Wenk]

I don't see any replies, so I'll take a stab at this.

I think most people are doing IHC. If not within their own lab, then they
are sending it out. Most labs don't get very many pituitary tumors, so
buying the primary antibodies is very expensive for most labs that will do a
pituitary IHC series once every X years.

The problem with these other histology special stains is two-fold, in my
opinion:

1. NOT TOO SPECIFIC:
The best one can determine is if a particular tumor cell is acidophilic
(staining with orange G, acid fuchsin, eosin, etc.) or basophilic (staining
with Schiff, blue dyes of trichromes, etc.). Acidophil pituitary cells
produce either growth hormones or prolactin producing cells. Basophil
pituitary cells produce thyroid stimulating hormone, adrenal cortical
stimulating hormones, or the gonadotrophins (follicle stimulating hormones,
leutinizing hormone).

So the best these beautiful histology stains could do it put the cells into
a category. So if the tumor staining positive with acid fucsin and orange G,
then it must be an acidophil tumor. But WHICH acidophil cell tumor - the
cell producing growth hormone, or the cell producing prolactin hormone? The
histology stains could not further differentiate than acidophil or basophil.
So how did the pathologists determine this differentiation? Well - what were
the symptoms of the patient? Was the patient growing taller (so must be a
growth hormone tumor) or were their breasts lactating (prolactin tumor)?

2. CHROMOPHOBES:
In any normal pituitary adenohypophysis (glandular portion, not the
neurohypophysis part), about 10% of the cells are basophils, about 40% are
acidophils, and about 50% are chromophobes - in other words, they don't
stain with histology special stains. These chromophobes are any of the
acidophils or basophils, but are simply not staining at that time. Possibly
they are "immature" with only a few chemicals/hormones, or possibly they
have recently released most of their chemicals/hormones, or possibly they
are waiting in reserve so don't have a lot of these chemicals/hormones.

For whatever the reason(s), these chromophobe cells do not have a lot of
granules, so don't stain well with histology special stains (or not at all).
And often, cancer tumor cells are so busy multiplying, they "forget" to make
the granules and hormones, so as a result, in my pre-IHC pituitary tumor
experience, the majority of pituitary tumors seem to be chromophobes.

Therefore, the advantages of IHC for pituitary are:
1. Can demonstrate the low levels of granules and hormones in chromophobes.
2. Can further separate pituitary acidophils and basophils into exactly what
hormone they are producing.

Hope this helps.

Peggy A. Wenk, HTL(ASCP)SLS
William Beaumont Hospital
Royal Oak, MI
----- Original Message -----
From: "Geoff McAuliffe" <mcauliff <@t> umdnj.edu>
Cc: <histonet <@t> pathology.swmed.edu>
Sent: Tuesday, February 17, 2004 8:09 PM
Subject: [Histonet] staining of anterior pituitary?


> Deal Histonetters:
>
>     I need the experience and opinions of those of you who do clinical
> work. What sort of staining is used for anterior pituitary glands these
> days? Immuno looking for specific cell types or is there still some
> PAS+Orange G, Azan, Herlant's, etc. staining going on?
>     Thanks!
>
> Geoff
>
> --
> --
> **********************************************
> Geoff McAuliffe, Ph.D.
> Neuroscience and Cell Biology
> Robert Wood Johnson Medical School
> 675 Hoes Lane, Piscataway, NJ 08854
> voice: (732)-235-4583; fax: -4029
> mcauliff <@t> umdnj.edu
> **********************************************
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