Understanding Pathology

Why do we indicate margins? What do they mean?

If I’m doing a shave or a punch of a spot I’m concerned about maybe squamous cell carcinoma or a basal cell carcinoma, it’s easy to know if the margins are positive you have to go back and treat it.  What do we do, though, if on the biopsy if it shows the margins were free or they were closely approaching the inked margins? My recommendation would be to go back and completely treat that and the reason is, we only see portions or sections of what you biopsy, so if we don’t see it go to margins, it’s very possible in another section it may actually extend to margins.  So I would recommend going back and treating them as you should treat them. Obviously you can do a destruction, you can treat it with chemotherapy.  If you’re going to do a standard excision with 4mm margins that’s an option.  Of course you can always do Mohs, depending on the location and indications.

One of the questions we get from some of the providers that send us biopsies is “Why, when we make a diagnosis of actinic keratosis, squamous cell carcinoma or Bowen’s disease “with follicular involvement” — why we say that.”

The main reason is sometimes you may have biopsied someone and it shows and actinic keratosis or an AK and it doesn’t respond to treatment. If we notice that it does extend along the follicles, it’s to help the provider be aware that normal treatments may not be effective for that because it is extending along the follicle— especially in areas of the body that have terminal hair that grow down quite a bit deeper.  Sometimes those atypical cells can extend deeper and be a little more challenging to treat.  The same thing goes with Bowen’s disease or squamous cell carcinoma in situ.  Some of the local or superficial treatments we do may be insufficient to cure those on areas with terminal hair where they extend a lot deeper.

Study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3366442/