Dear Kim:
 
>I hope someone can benefit from this info in the future.  Forgive me if
>it's boring.  I love this stuff!
 
For a pathologist, it is far from boring!  It's what I do.
 
If you don't mind, I'd like to give an interpretation here.  I don't think
we are out of the woods quite yet, and extreme vigilance is important.
 
While it is not a squamous cell carcinoma or a leiomyosarcoma, apocrine
tumors in this location are occasionally bad news.  Malignant sweat gland
tumors can be well-differentiated, and these tumors have a nasty propensity
to metastasize early to internal lymph nodes.  Personally, I'd rather have
the leiomyosarcoma - a malgnancy of the smooth muscle of either blood
vessel or urianry tract walls, because they offer the best hope of a
surgical cure if they are truly malignant.
 
The fact that the mitotic rate (or the number of cells that are dividing)
is up to 3 in some fields is of some concern.  I have seen a number of
similar tumors, and some have been bad actors.
 
Let me make two suggestions.
1) Keep a very close eye on this lesion - if it turns out to be a
malignancy, its not good.  In apocrine malignancies of the vulva in the
female and prepuce in the male, metastasis often occurs prior to anyone
ever seeing the first sign of a problem, and well before surgery.
2) If you can contact your vet and the patholigst, I'd be happy to look
at the tumor and see if I can identify as to benign or malignant.  I've
seen a number of these before.  Actually, I've recently started a study
on this type of tumor, and one more neoplasm - I've currently got eight
in the archive will certainly strength the study.
 
With kindest regards,
Bruce Willams, DVM
[Posted in FML issue 3297]