Mycosis Fungoides

00:01 Continuing our discussion of skin cancer.

00:04 We have mycosis fungoides.

00:07 First and foremost, please understand it has nothing to do with fungi, and I’ve mentioned that prior.

00:11 And so therefore, what is it? It’s a T-cell lymphoma.

00:14 A T-cell lymphoma.

00:15 Remember, if we’re dealing with the skin, then you should be thinking about T-cells.

00:20 If we’re thinking about the GI, then you should be thinking about your B-cells.

00:25 So here, we have a lymphoma that is in your tissue of T-cell origin I said tissue.

00:33 Because with mycosis fungoides, you’re not going to find a description clinically known as erythroderma.

00:40 What I mean by that is what if this T-cell lymphoma wants to leave the tissue and then go onto circulation? If it does, then you call this condition Sézary syndrome.

00:52 So the only difference between mycosis fungoides and Sézary is the location of your T-cell lymphoma.

00:59 If the T-cell lymphoma is located in your tissue and you call this mycosis fungoides, it is the most common form of cutaneous T-cell lymphoma.

01:09 Usually diagnosed after years and years because, well, it’s rare and the fact that you would be misdiagnosed or perhaps your doctor doesn’t even suspect it.

01:19 Or maybe even the patient just thinks that it’s eczema or some type of dermatitis.

01:27 As far as etiology, really idiopathic.

01:33 And morphology becomes important.

01:35 If you take a look at the skin here upon gross examination, you will notice that it is erythematous.

01:40 However, you would not refer to this as being erythroderma.

01:43 If it’s Sézary syndrome, if the T-cell lymphoma actually left the tissue and went into your circulation, you call this Sézary cells and therefore, the skin, 80% of your skin, almost all of it, would appear as being erythematous.

01:59 You call that erythroderma, which is not the description in presentation of mycosis fungoides.

02:05 Well-demarcated, atrophic, erythematous plaque with slight scale is your description.

02:15 Often involves double-protected skin beneath undergarments.

02:18 And by that, we mean there is nothing to do with exposure to UV rays as being a risk factor.

02:25 More advanced cases may then present as your spreading or we can call it a leukemic phase.

02:32 What does that mean? That means that now you have your T cells, your neoplastic cells that have left the tissue, have entered circulation and you call this Sézary phase and this is what I was referring to as being your erythroderma.

02:46 Here’s the skin and what you’ll notice here is going to be your erythematous type of plaque that you can expect with mycosis fungoides.

02:55 Where would you then expect these neoplastic cells to be located? In your tissue.

03:02 Pathology: Atypical lymphocytes are epidermotropic or home to the epidermis.

03:10 Pautrier abscesses formed of aggregate of atypical lymphocytes, quite significant and specific for mycosis fungoides.

03:20 And studies of gene rearrangement often demonstrate a clonal type of population with mycosis fungoides.

03:27 Pautrier microabscesses, it’s the aggregates of these atypical lymphocytes because you call this one of the most common cutaneous T-cell lymphoma.

03:41 Management: Well, advanced cases at this point refer to specialist.

03:43 advanced cases at this point, refer to specialist.

03:46 That is as far as I’m going to go here and probably all that you need to know at this juncture in your medical education.