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For each of the ten cases, study the image(s) and then answer the questions. You can click on the image to view a larger version if required.
Each case should take approximately five minutes to complete. There is a list of suggested further reading material at the end of the quiz.
When you finish the quiz, you can download a certificate.
What was the original lesion?
The original lesion was a sebaceous naevus, also known as Naevus of Jadassohn. It is an organoid naevus, usually present at birth, consisting of proliferations of the epidermis, hair follicles, connective tissue, apocrine and sebaceous glands. At first it is a sharply demarcated hairless yellowish plaque but at puberty it becomes verrucous and nodular because of the action of androgens on the sebaceous glands.
What has happened to it?
It has developed a tumour within it. The majority of tumours are benign, including syringocystadenoma papilliferum and syringoma, but malignancy may occur (basal cell carcinoma, as in this case, or sebaceous carcinoma).
What treatment would you advise?
The entire lesion should be excised. The patient illustrated was referred to a plastic surgeon, who removed the lesion by serial excisions thus avoiding a skin graft. Ideally, sebaceous naevi are removed in childhood or adolescence.