[Histonet] Histonet Digest, Vol 161, Issue 5Subject: Re: Processing cystic tissue

[Steve McClain]

Skin cysts are difficult for everyone.  Cysts and toenails lead the top of our list of cases with catastrophic tissue loss - which we define as tissue loss w "holes" >1mm2 square.

The cyst center generally does not fix readily, composed of unfixed cornified cells and waxy lipid. On the scalp, wens or isthmus-catagen cysts are also  calcified. The outer aspect may include dermis and scar and inflammation and also the squamous cyst lining. All of these factors limit diffusion and penetration of fixatives and processing alcohols/clearants/paraffins.

We open all cysts by slicing into them and allow them to fix another 6-8 hours in fresh 10%NBF, then process on a long cycle of 12-16 hours, beginning in 50% alcohol in station 1. 12 hours is our standard overnight cycle and 16 hours is used for toenails.

Our cyst slides are still not perfect, but are sufficient to make a photomicrograph-our usual method-we photograph every specimen.

Steve A. McClain, MD

> On Apr 5, 2017, at 13:23, "histonet-request at lists.utsouthwestern.edu" <histonet-request at lists.utsouthwestern.edu> wrote:
> 
> Subject: Re: [Histonet] Processing cystic tissue