How Mohs Surgery Treats Skin Cancers - Yale Medicine Explains

Transcript

• 00:05The epidermis is very, very
• 00:06thin. It's only about the
• 00:08thickness of a sheet of
• 00:09paper, so less than one
• 00:10millimeter thick. And there's a
• 00:12lot of cells that are
• 00:13packed in there doing this
• 00:14important job of protecting your
• 00:16body from the external environment.
• 00:18There are keratinocytes
• 00:20which are the most common
• 00:21cells and they start at
• 00:24the bottom,
• 00:25the basal layer. And then
• 00:27as the cells move up
• 00:28into the upper layers of
• 00:29the epidermis,
• 00:30they do what's called differentiation
• 00:32and they change their function.
• 00:34They become more and more
• 00:36plate like or squamous.
• 00:38To become more of an
• 00:39effective barrier to the external
• 00:41environment.
• 00:42And the third type of
• 00:43cell that you see in
• 00:44the epidermis
• 00:46is the melanocyte,
• 00:47the pigment producing cell.
• 00:49And the melanocyte is obviously
• 00:51extremely important
• 00:53because
• 00:54it provides protection against ultraviolet
• 00:57radiation,
• 00:58which is damaging to the
• 00:59skin.
• 01:00The sun exposure causes the
• 01:02UV damages, and while our
• 01:04body does its job to
• 01:06repair those damages, chronic sun
• 01:08exposure or intense sun exposure
• 01:11can lead to more damages.
• 01:13Over time, if those basal
• 01:14cells that live in the
• 01:16basement of the skin
• 01:17develop mutations in their DNA,
• 01:19these are gonna get passed
• 01:21along as they're reproducing and
• 01:23repopulating the skin.
• 01:25More mutations will develop. That
• 01:27cell will then lose all
• 01:28of its control and continue
• 01:30to grow and destroy the
• 01:32surrounding tissue. And that is
• 01:33the definition of cancer.
• 01:41Skin cancer is typically categorized
• 01:43into non melanoma skin cancer
• 01:45as well as the melanoma.
• 01:47Non melanoma skin cancers are
• 01:49most commonly squamous cell carcinoma
• 01:51and basal cell carcinoma.
• 01:53Basal cell skin cancer tends
• 01:55to grow slowly.
• 01:57It is unlikely to spread
• 01:59or metastasize to other areas
• 02:01in the body. So that's
• 02:02good news. But it is
• 02:03very persistent in its growth.
• 02:05And so while it grows
• 02:06slowly,
• 02:07it can grow to a
• 02:08very large size
• 02:09and be very destructive to
• 02:11surrounding tissues over a period
• 02:13of years.
• 02:14Unlike basal cell, squamous cell
• 02:16skin cancer can spread outside
• 02:18of the skin and can
• 02:20cause metastasis
• 02:22and mortality for patients.
• 02:25Melanoma, while being much less
• 02:27common,
• 02:28is more concerning because it
• 02:29has a higher rate of
• 02:30spread.
• 02:31And melanoma, of course, has
• 02:33historically been a very lethal
• 02:36disease in the advanced stages.
• 02:38However, the good news, and
• 02:39I can't emphasize this enough,
• 02:41that the majority of melanomas
• 02:43are discovered
• 02:44at an early treatable stage,
• 02:46ninety six percent.
• 02:48Skin cancer can really look
• 02:50like many things and can
• 02:53mimic
• 02:53benign conditions of the skin.
• 02:55And so this is why
• 02:56it's really important to have
• 02:57your annual screening exam with
• 03:00a board certified dermatologist
• 03:02because their trained eye will
• 03:03be able to pick up
• 03:05what is, you know, a
• 03:06skin cancer that needs to
• 03:07be biopsied.
• 03:13So most skin cancers, especially
• 03:15basal cell and squamous cell
• 03:16skin cancer, can be cured
• 03:18with surgical removal.
• 03:20We have various surgical approaches
• 03:23to treat skin cancer,
• 03:25which include a standard excision
• 03:26where the skin cancer is
• 03:28removed, sent off to pathology.
• 03:30If it's a lesion
• 03:32on the body that has
• 03:34a pattern under the microscope
• 03:35or it has little roots,
• 03:37then the Mohs technique, which
• 03:38allows us to excise the
• 03:40tumor in the office and
• 03:42study it while the patient
• 03:43waits, is the preferred approach.
• 03:46It allows us to assess
• 03:48the margins better. The margins
• 03:50meaning
• 03:51around the skin cancer as
• 03:52well as the base of
• 03:53it. We're able to visualize
• 03:55theoretically a hundred percent of
• 03:57the margins and be more
• 03:58confident that we had removed
• 04:00all the skin cancers.
• 04:02So most skin cancers will
• 04:03start in the epidermis,
• 04:05but once they become cancerous,
• 04:07they invade into deeper tissues.
• 04:10Mohs surgery allows us to
• 04:11be as precise as possible
• 04:13when we're doing this because
• 04:14we can track that tumor
• 04:16tumor under the microscope as
• 04:17we go. And it allows
• 04:18us to achieve that highest
• 04:20cure rate of making sure
• 04:21we're removing all of the
• 04:23tumor that we can detect,
• 04:24as well as preserving any
• 04:26normal tissues that are nearby
• 04:28and not removing anything more
• 04:29than what we need to.