Derma Case: 58-year-old Man with a Lesion on the Tip of His Nose

00:03 I think we've wrapped up that case.

00:05 She's certainly going to need a biopsy to definitively identify this lesion and then decide what type of tumor she has and how to proceed.

00:14 Let's move on to another case now.

00:17 This is a 58-year-old farmer with a past medical history of diabetes and hypertension who's presenting with a lesion right on the tip of his nose as shown here.

00:26 Now, he thought it was a pimple but he's noticed it growing over the past six months denies any pruritus.

00:33 Social and family history: he's a non-smoker.

00:35 He spends, again, most of his day in sun-exposed areas.

00:39 Review of systems is unrevealing.

00:41 Initial vitals, likewise unrevealing.

00:44 Now again, I want you to try and describe this skin lesion without help from me.

00:52 The way I would describe this again, this is a person with fair complexion.

00:56 There is a single 1.5 centimeter dome-shaped, pearly translucent papule on the tip of the nose with visible telangiectasias.

01:08 Which of the following is the most likely diagnosis? Some of the same characters we looked at before: melanoma, keratoacanthoma which we haven't talked about yet seborrheic keratosis, and then the non-melanoma skin cancers: basal and squamous cell carcinoma.

01:24 Now, you might be thinking melanoma that doesn't really look like a melanoma on the tip of his nose.

01:30 But keep in mind, there are several different subtypes of melanoma including the nodular subtype depicted here that could certainly be what he's got on his nose.

01:39 I think we have to keep that on our differential and only a biopsy will really give us the answer for that one.

01:45 It's also important to keep in mind epidemiology here.

01:50 Melanoma skin cancers only represent 2% of skin cancers and contrast basal cell and squamous non-melanoma skin cancers they are the vast majority of skin cancers.

02:02 From a probability standpoint, melanoma is probably not what's going on here.

02:05 But nonetheless, it's such a severe diagnosis especially if it's a nodular type which has that vertical growth phase.

02:14 We have to be mindful of that and look forward on biopsy.

02:18 But let's talk about keratoacanthoma here for a moment which is not really a skin cancer per se.

02:24 It's been variably described as either a pseudocancer or at worst, a low-grade malignancy.

02:31 It usually is on the face, as is the case in our patient.

02:34 It occurs in elderly patients over the age of 50.

02:37 It does have an association with HPV, though not uniformly present.

02:42 One of the unusual things about this lesion is that it does have a rapid growth phase.

02:47 You can be very concerned that it could be cancer because over the span of weeks you could go from having a tiny, tiny little papule to something that could be a centimeter or two or even three in size.

02:57 Also interestingly, it can spontaneously resolve.

03:00 It's a very unusual type of condition and something to be aware of.

03:06 It mimics squamous cell carcinoma in that way the way that it appears and the way that it can grow.

03:12 It has again a nodular, dome-shaped, central keratotic plug.

03:17 Similar to what we're seeing in our patient though the central keratotic plug is not something that was described on exam and not something that we're seeing.

03:25 Without that keratinized central plug I think we can take keratoacanthoma off the list.

03:31 Now here again, we're looking at seborrheic keratosis.

03:34 This again has this characteristic stuck-on type of appearance and it's often in not sun-exposed areas.

03:42 Our patient has this lesion right on the tip of his nose.

03:45 It's got those telangiectasias.

03:47 It's more of a reddish coloration.

03:49 I don't think seborrheic keratosis is where we're going here.

03:53 Let's leave that one off the list and move on to the next one.