Dermoscopy

Dermoscopy of basal cell carcinoma CME

Created 2008.

Learning objectives

• Describe dermoscopic features of basal cell carcinoma

Introduction

Dermoscopy is useful to distinguish pigmented basal cell carcinoma from other pigmented lesions. There are specific features that help to distinguish these. Pigment may be grey, brown, blue or black. They are rarely completely pigmented in white-skinned individuals.

Pigmented basal cell carcinoma

The dermoscopic features of pigmented basal cell carcinoma include:

• Absence of pigment network
• Linear and arborising (branch-like) telangiectasia
• Structureless or leaf-like areas on the periphery of the lesion
• Large blue-grey ovoid nests or blotches
• Multiple blue-grey globules
• Specks of brown and grey pigment
• Spoke wheel areas (radial projections from a well circumscribed dark central hub)
• Focal ulceration

Blue ovoid nests

Arborising blood vessels,

Focal ulceration

Ulceration

Spoke-wheel pigmentation

Flecks of pigment

Arborising telangiectasia

Flecks of pigment

Flecks of pigment

Deeply pigmented border

Multicoloured lesion

Large nodule

In some cases, it may be difficult to distinguish deeply pigmented or even non-pigmented basal cell carcinoma from melanoma.

Non-pigmented basal cell carcinoma

Non-pigmented basal cell carcinomas are much more common than pigmented basal cell carcinoma. They contain flecks of grey colour.

Experienced dermoscopists can often diagnose superficial basal cell carcinomas by their typical bluish-pink colour, asymmetrical arborising vessels and focal ulceration. Slight scaling and white areas of regression may also be present. Chrystalline structures, i.e. white shiny lines, strands and larger irregular-shaped white areas, are common in all histological types of basal cell carcinoma. These short parallel or disordered lines and roundish white structures are often only visible on polarised dermoscopy.

Nodular basal cell carcinomas lose the blue hue and instead have a white rim around central ulceration. Milia may be present. Disordered and streaky crystalline structures may be seen.

Bluish, scale, ulceration,

Subtle blue colour

Milia formation

Prominent vasculature

Vascular bcc

Crusting, telangiectasia

White nodule, telangiectasia,

Tiny ulcers

Superficial basal cell carcinoma

Superficial basal cell carcinoma

Cystic basal cell carcinoma (polarised view showing crystalline structures)

Cystic basal cell carcinoma (non-polarised view)

Activity

Imiquimod cream has restricted subsidy by PHARMAC for treating certain superficial basal cell carcinomas (New Zealand, September 2008). Observe the inflammatory response to treatment using dermoscopy.