Basal cell carcinoma — SCE Dermatology MCQ

Correct answer: E — Nodular basal cell carcinoma

The correct answer is E, nodular basal cell carcinoma. The classic description of a pearly papule with arborising (branching) telangiectasia and a rolled, translucent border on a sun-exposed site of an older adult is the textbook presentation of nodular BCC. Slow growth over many months, intermittent crusting or bleeding, and the absence of a pigment network on dermoscopy (excluding melanocytic lesions) all fit nodular BCC rather than a melanocytic or rapidly evolving keratinocytic tumour. Dermoscopically, nodular BCC characteristically shows arborising vessels, ulceration and blue grey ovoid nests, none of which suggest melanoma or SCC. This morphology and growth pattern is exactly why BCC is flagged for routine (non urgent two week wait) dermatology referral in UK primary care guidance. Why the other options are wrong: D. Cutaneous squamous cell carcinoma: SCC typically presents as a tender, indurated, hyperkeratotic or ulcerated nodule that grows more rapidly over weeks to a few months, not a smooth pearly papule with arborising vessels. C. Amelanotic melanoma: this lacks pigment too, but usually shows atypical polymorphous vessels, a pink or red nodule that grows faster, and no rolled pearly edge; absence of pigment network does not itself confirm melanoma. A. Keratoacanthoma: grows rapidly (weeks), forming a dome shaped nodule with a central keratin plug, then often spontaneously regresses, unlike this 18 month indolent course. B. Sebaceous hyperplasia: presents as small yellowish papules with a central dell and crown vessels on dermoscopy, not arborising telangiectasia or a rolled border. Key point: Arborising telangiectasia plus a pearly, rolled border on a slow growing facial papule is pathognomonic for nodular basal cell carcinoma.

Reference: NICE CKS, Skin cancers - recognition and referral, https://cks.nice.org.uk/topics/skin-cancers-recognition-referral/