Case discussion: How would you treat this patient? [1 May]

In this week’s case discussion from Dr Heather Lawson, we look at a 64-year-old male patient with a personal history of basal cell carcinoma 10 years ago and a family history of a father with melanoma. The patient presented to Dr Lawson’s clinic for the first time after being referred by his GP for removal of a cyst on his back. The cyst had been growing over the past six months.

When Dr Lawson examined the lesion, she felt it was more likely to be solid than cystic, so she excised it in its entirety, different from how she excises cysts (whereby she cuts a small ellipse in the centre of the cyst). The lesion was solid.

What are your thoughts on the potential diagnosis?

case discussion


Here is the pathology report:

A note from Dr Heather Lawson:

I really thought this was a melanoma. I have seen a 2cm thick spindle cell melanoma that looked like a cyst to two of the patient’s GPs, resulting in a 5 month delay in excision. I have researched that Dermatofibromas can be up to 15mm wide, but I have never seen one like this before. I did ask the pathologist to recheck, and the diagnosis was the same.

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case discussion


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16 comments on “Case discussion: How would you treat this patient? [1 May]

  1. Probably a skin cancerBCC/SCC /Merkle tumour /Pagets –clue on magnified view irregular lobulation and vessels –would have excised

  2. This is a difficult diagnoses because none of the usual features are present. Lack of pigment, no vessels, no obvious scale or features of squamous cell. Possibly a type of basaloid sebaceous tumor, or type of lipoma/epithelioma. I have seen a trichoepithelioma and that would be my best guess – usually occur on the face, but the one I excised was on the back.

    The approach is correct, excise the whole lesion and get a definitive diagnosis.

  3. Suspicious almelanotic ugly duckling lesion; pink white with some abnormal vasculature.
    Punch biopsy and then excision depending on histology

  4. A quick growing firm nodule is a concern. Most of the pathology looks deep. The surface epidermal views are not much to look at. A variegated lenticular network with white structureless areas with the odd brown globule. The BVs around the periphery are not in focus some are linear irregular and dotted but it is not clear.
    IMPRESSION a desmoplastic nodular melanoma/cutaneous sarcoma/lymphoma, until proved otherwise A dermatofibroma does not change, but this lesion could be in the acute phase.

  5. Erythematous nodule with smaller ones on the rest of the back. Dermatology is centrally pale with a punctum but has brown reticular pigment pattern 11 to 1 O clock. At 6 O’clock there are irregular grey structures with dark brown clods dots. Vessels are sparse but look polymorphic. This could be a collision lesion Epidermoid Cyst and Melanoma.

  6. First determined by clinical stage of basal cell carcinoma. After surgical resection and immunotherapy. The immune system stimulates and strengthen the autoimmune defence system fight off any remaining cancer cells .

  7. This is a nodular melanoma,There is Chaos and pseudo network. Excision biopsy with 5 mm margin followed by Treatment based on Histology would be my line of management for this patient

    1. Hi Harshad

      What is the purpose of 5mm margins as an excisional biopsy?

      If this were nodular melanoma – it would require 10mm margins as a minimum.
      If this returns benign (as it did) – then the margins taken were larger than required and increased surgical risk and impacts.


  8. Looks like a kissing lesion to me on dermoscopic picture.
    Lower part has features of dermatofibroma and the upper part is more consistant of seb.k. Since is has been growing over the last 6 months the diagnosis of dematofibrosarcomas has to be excluded.

  9. Hi All

    A few responses were similar to ‘not sure’, or ‘no idea’. This is perfectly fine and will happen from time to time.

    In these cases – it is always true that a diagnostic procedure should be performed in order to determine the aetiology.

    In this case – within the differential (right) was nodular melanoma, and thus the best method for diagnosis is an excisional biopsy to include the entirety of the lesion for the pathologist.

  10. It does seem to have a central scar but even so. There would be no way I would leave something like that on a patient – would excuse or refer. I am
    Non skin specialist GP. The pathology report is a surprise- I definitely thought it be a squamous cell carcinoma as it seemed to have a bit of keratin.