Thanks for joining me on this discussion of melanoma.
Melanoma is a malignancy of melanocytes
which produces our pigments.
This is variable expression of the melanocytes
and the pigmentation is the reason
why we all have different skin colors.
Here, in this image,
you notice the different versions of
melanoma on various parts of the body.
The risk factors for melanoma include sun exposure,
family history of melanoma or skin cancers,
a personal history melanoma or skin cancers,
and dysplastic nevus.
This is why it’s important to elicit a thorough history.
This is particularly true about sun
exposure and multiple sunburns.
That's why melanoma is more
likely in fair skinned patients.
On physical examination,
it’s very important to completely disrobe the patient
and not only look at the front, but also the back.
Remember, much of the sun exposure,
particularly on beaches,
is actually on the back.
This is a difficult area for the
patient to examine themselves.
So, as clinicians,
we have to do a thorough examination.
These are some very important physical
findings when characterizing melanoma.
For every patient and every
melanoma, potential lesions,
we want to look at the ABCD system.
A for asymmetry.
B, take a look at the lesion.
Does it have jagged, irregular edges?
That's more concerning.
Next, take a look at the color.
Pigmentation itself is associated
with a likelihood of a cancer.
sizes or lesions greater than 6 mm
may have more chance of harboring cancer.
Unfortunately, no lab –
routine laboratory values are likely to be helpful.
Sometimes, an LDH value is gotten
to follow the patient after surgical cure.
When you’ve made the diagnosis of melanoma,
it's important to make sure that
the patient has not had a metastasis.
It’s important to do a metastatic workup
with a CAT scan cross-sectional imaging
of the chest, abdomen and pelvis.
Unfortunately, in this patient,
you see many, many liver metastases.
patients undergo a CT PET scan.
In general, oncologic processes are PET-avid,
meaning glucose that has untagged nuclear medicine
is likely to be up-taken at a higher
rate in cancers than normal tissue.
In this unfortunate patient with metastatic melanoma,
you see multiple regions
in the chest and the abdomen
that is hot on a PET scan.
Now that you've decided the
patient is appropriate for surgery,
what margins do you need for this oncologic process?
the depth of invasion based on your biopsy
is the single most determinant
of the necessary margins.
in thin melanomas, or 1 mm or less,
we usually require 1 cm disease-free margin.
Between 2 and 4 mm,
we require 2-cm margin.
And those that are greater than 4 mm,
we’re not exactly sure how much
more of a margin we need,
but they definitely need to be at least 2 cm.
Remember, much like the breast lectures,
sometimes patients with melanoma
have lymph node metastases.
These lymph node metastases have poor prognosis.
And much like breast diseases,
sometimes patients undergo
sentinel lymph node biopsies.
Sentinel lymph node biopsies of melanoma
is by the same theory
that, generally speaking,
one or two nodes is the sentinel
node of the draining basin.
Now, it's time to revisit some clinical pearls
and high-yield information.
Remember, melanoma has
multiple variants histologically,
but the workup is the same,
including the metastatic workup.
Generally, the treatment is the
same as well in terms of surgery.
And also remember,
melanoma is one of the most common
sources of small bowel metastases.
Remember, metastases to the small bowel,
think melanoma on your clinical examinations.
Thank you very much for joining me
on this discussion of melanoma.