Brent Spencer, MD

First off, 50% TCA is not meant to be an "at home" peel.  It is very strong and should only be used by qualified individuals.  From your picture, it looks as if you did this on your finger.  I would have also advised against that.  A 50% TCA peel is way too strong for that location.

 

The frost after a TCA peel does not wash away.  You may have over peeled yourself, and there is a potential for you to scar.  I would advise you go see your local dermatologist in the meantime.  Keep the area moist with vaseline and hope for the best.

Yes, a frozen section biopsy can be done prior to Mohs surgery.  I tend to limit this practice to very few situations though.  For example, if there is a suspicious lesion immediately adjacent to where I am working, I want to know what it is, as it could affect my closure.  

 

The potential negatives include:

1.  A frozen section biopsy does not provide the same cellular detail and can have artifact that a permanent section biopsy does not have.

2.  There may be a bias that develops when reading a biopsy right before surgery...of course the incentive is to read this out as a BCC (when it may be something like a trichoepithelioma instead).  If the biopsy is read by another dermatopathologist, this potential bias is eliminated.

3.  Sometimes it is difficult to make a diagnosis and  you may require immunohistochemistry studies or need a second opinion.  Doing the frozen section biopsy right before Mohs makes it very difficult to do this.

4.  What if your biopsy is negative right before Mohs?  Then the doctor has blocked a large amount of time on his schedule for your potential Mohs surgery which is cancelled.  This is not fair to other patients who are waiting for this procedure and creates a scheduling nightmare.

 

So there are many negatives with doing this approach of biopsies immediately before Mohs.   

It is impossible to tell you what is going on without seeing the lesion.  You would be best served by calling a local board-certified dermatologist.  The American Academy of Dermatology (aad.org) has a list where you can find one. 

Blue Light is not my treatment of choice for nodular basal cell carcinomas; the light does not penetrate deeply enough to get nodular BCCs.  In low risk areas (like the trunk and extremities), Blue light may be acceptable for superficial basal cell carcinoma.  Blue light in my opinion is never indicated for recurrent BCCs (as is the case on your nose).    Furthermore, I would not do Blue light for the BCC on your forehead.  The cure rate is nowhere close to that of Mohs (which is 99% for primary tumors).

 

In terms of scarring, make sure that you go to a fellowship-trained Mohs surgeon.  These individuals are extensively trained in reconstruction.  Although you will develop a scar, a fellowship-trained Mohs surgeon should be able to keep this to a minimum.  

I wouldn't call what you are having "Mohs".   You might call it the slow Mohs variant if they are really doing en face sectioning of the tissue.  More appropriately, I would say that you are having staged excisions where they are doing permanent sections with immunohistochemical stains.  This is not abnormal to do for rare tumors.   The staining and processing take time when it is done this way. 

The same day procedure that you read about for Mohs is when frozen sections are done.  In rare instances, immunohistochemistry is done on frozen sections, but for the most part, permanent sections is where you see this utilized.