Case discussion: How would you treat this patient? [3 May]

Case submitted by Dr D. Carragher

A 72 year old man who was an outdoor worker has regular skin checks. He presented last week with this lesion which had been there for 40 plus years and said it had changed recently.

Clinical image


Do you think this lesion is suspicious of benign? Why?


Dermatoscopic image


Here is the dermoscopy image. Using the 3 point checklist, how would you describe this? And, what is your preferred diagnosis?

How would you biopsy this lesion and why?


Pathology report


Ant chest – Ellipse of skin measuring 31x14x9mm with a variegated pigmented plaque measuring 17x13mm 6PALE 28 2L

Sections show an irritated, broad based moderately atypical compound melanocytic naevus with marked pigment incontinence. Margins appear clear. Deep margin: 3~m
Peripheral margin: 0.5mm
In the centre the dermal component is regressing. Overlying in area, there is a continuous lentiginous melanocytic proliferation with some Pagetoid spread, consistent with melanoma in situ. Margins appear clear.
Deep margin: 5mm
Peripheral margin: 2mm


Clinical Notes:
Prev SCC positive margins.

Macroscopic Description:
Pot l:Right leg lesion: Skin ellipse 35x30x5mm with a central dark brown crusty nodule 24x20x2mm. Staple R superior, on form states staple R proximal. (A-Ex2ts. vg.r.i . jg)

Microscopic Description:
Sections show skin with a well differentiated squamous cell carcinoma. The dermis shows solar elastosis. No vascular or perineural invasion
is seen. Granulation tissue and scar are also seen.

Excision skin right leg: Squamous cell carcinoma, margins clear.

Please share your thoughts in the comment section below. Professor David Wilkinson will provide his opinion and advice.

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17 comments on “Case discussion: How would you treat this patient? [3 May]

  1. 2 mm excision biopsy as irregularly shaped , and heavily pigmented peripherally with central regression and with a history of change it is imperative to get a histological diagnosis.

  2. Looks like a traumatised fibroma or something
    like that eg Seb wart on his back.
    However history would suggest doing something active if dermoscopy is not definitely benign

  3. Hi
    Any naevus with a recent change I should perform an excisional biopsy with 2mm margin. The lesion is clinically melanotic as it is a naevus. Any change should alert for the possibility malignant change.

    1. The lesion seems chaotic with 3 colours, deep black, gray veil and irregular brown colour at periphery. 40 years hx is suggestive of naevus.

  4. This lesion looks slightly raised with a rough surface and from the macro shot I suspect a seb K. In real life I would palpate it and also look dermoscopically
    My initial impression is a traumatised seb K with some old blood under the edge giving the black discolouration.
    If I am convinced this is a sebk after dermoscopy, it could be shaved which would be diagnostic and therapeutic.
    If the lesion is raised and pigmented or macular and smooth an excisions biopsy with 2mm margin to exclude melanoma.

  5. Some great comments here – thanks to everyone for jumping in. The question I asked “suspicious or benign” is pretty easy to answer: nobody can say for sure that it is benign. We need more information before we can make that call. It is however an “ugly duckling” – from what we see here, it stands out alone. That said, seb k is an option. What is against seb k, is that the patient says it has been there a long time; seb k is a lesion of older people but says he has had it for 40 years or more. Maybe a long standing nevus that is developing melanoma is an option. It could also be a very very slow growing melanoma. Anyway, not confident that it is benign, and looking very suspicious. Dermoscopy needed

    1. chaos of colour with regression and polymorphic vessels makes me very suspicious of melanoma

    2. Its certainly suspicious, and has peripheral streaming on the periphery, plus blue gray veil and asymmetry.

  6. According to the 3 point check list you need 2/3 asymmetry, atypical network or blue-white structures. This lesion provides all 3 criteria, definitely asymmetrical, areas of thickened network and an area of regression with blue-white structures. I’ll certainly retract my initial impression of sebK after seeing the dermoscopy and proceed to excisions biopsy.
    I appreciate your point about the length of time it had been there. Obviously it had been there some time but I find patients are particularly unreliable at determining how long a lesion had been there or whether it was different.

  7. Greetings
    I excised this lesion, on the following grounds
    1) the patient is well known to me and is very reliable, I did exam him last year and noted the lesion but dismissed it as it had been stable for 40 odd years and had NO worrying factors. I might add I was very worried I had missed something until I saw the pathology, which follows
    2) definite chaos on microscopy and an irregular border.

    Pathology follows

  8. Dermoscopy score is at least 2 out of 3: asymmetry and white scar like depigmentation. So biopsy is now mandatory to clarify the suspicion that this is melanoma. What is the biopsy method of choice here?

    1. for me there is no choice but a 2mm excision biopsy .
      if there was no purple/blue might consider a shave removal

  9. I agree with Charlie. Excision biopsy with 2 mm margins.
    I like shave biopsies, particularly for atypical pigmented macules but it this case where the likely diagnosis is melanoma the excision biopsy is the way to go.
    You can determine margins more accurately than a shave and there is absolutely no doubt as to the position of the original lesion and biopsy, if there is some time delay between diagnosis and formal excision.

  10. I agree. The key principle here is that we need to remove the whole lesion for a definite diagnosis. So, we have an in situ melanoma. What treatment is recommended?