Basal cell carcinoma dermoscopy

What is basal cell carcinoma?

Basal cell carcinoma (BCC) is a common, locally invasive, keratinocytic, or nonmelanoma skin cancer. It is also known as rodent ulcer and basalioma. Patients with BCC often develop multiple primary tumours over time.

Basal cell carcinoma can be pigmented or nonpigmented. Its subtypes include:

• Nodular
• Superficial
• Morphoeic (also known as sclerosing and infiltrative)
• Other less common variants.

What are the clinical features of basal cell carcinoma?

The clinical features of basal cell carcinoma are:

• Slowly growing irregular nodule or plaque
• Skin coloured, pink, or pigmented
• Size varies from a few millimetres to several centimetres in diameter
• Spontaneous bleeding, erosion, or ulceration.

Clinical features of nodular basal cell carcinoma

Nodular basal cell carcinoma is the most common type of facial BCC. The clinical features of nodular basal cell carcinoma are:

• Shiny or pearly nodule with a smooth surface
• May have a central depression or ulceration, so its edges appear rolled
• Blood vessels crossing its surface
• The cystic variant is soft, with jelly-like contents.

Nodular basal cell carcinoma

Nodular basal cell carcinoma, leg

Nodular basal cell carcinoma, arm

Clinical features of superficial basal cell carcinoma

Superficial basal cell carcinoma is the most common type of BCC in younger adults and is the most common type on upper trunk and shoulders. The clinical features of superficial basal cell carcinoma are:

• Slightly scaly, irregular plaque
• Thin, translucent rolled border
• Multiple microerosions.

Superficial basal cell carcinoma, arm

Superficial basal cell carcinoma, leg

Superficial basal cell carcinoma, trunk

Clinical features of morphoeic basal cell carcinoma

Morphoeic basal cell carcinoma, also known as morpheic, morphoeiform, or sclerosing basal cell carcinoma, is usually found in midfacial sites. It can have wide and deep subclinical extensions and may infiltrate cutaneous nerves (perineural spread). It presents as an indistinct, waxy, scar-like plaque with ill-defined borders.

Morphoeic basal cell carcinoma

Morphoeic basal cell carcinoma

Morphoeic basal cell carcinoma

What are the dermoscopic features of basal cell carcinoma?

The dermoscopic features of basal cell carcinoma vary according to subtype.

Pigmented basal cell carcinoma

The dermoscopic features of pigmented basal cell carcinoma include:

• Absence of pigment network
• White, pink, grey, or light brown stroma
• Sharply defined, fine linear and branching serpentine vessels — these are also known as arborising vessels
• Structureless or leaf-like areas on the periphery of the lesion — these present as brown to grey-blue discrete bulbous blobs with pigment converging on a less-pigmented area
• Large blue-grey ovoid nests or blotches, also known as large clods
• Multiple blue-grey dots and clods
• Specks of brown and grey pigment (peppering, buckshot scattering)
• Concentric structures — dark central clod within a light brown larger clod
• Spoke wheel areas — these present as radial projections from a well-circumscribed dark central hub
• Short white lines or perpendicular white lines under polarised light only
• Focal ulceration
• Adherent fibre.

Branching serpentine vessels and blue-grey ovoid nests in pigmented basal cell carcinoma dermoscopy

Branching serpentine vessels, leaf-like structures, blue-grey and brown dots in pigmented basal cell carcinoma dermoscopy

Leaf like areas in pigmented basal cell carcinoma dermoscopy

Leaf-like structures in pigmented basal cell carcinoma dermoscopy

Adherent fibre, leaf-like structures and serpentine vessels in pigmented basal cell carcinoma dermoscopy

Blue-grey ovoid nests in pigmented basal cell carcinoma dermoscopy

Spoke wheels in pigmented basal cell carcinoma dermoscopy

Perpendicular white lines, blue globule, leaf-like structures in pigmented basal cell carcinoma dermoscopy

Nonpigmented basal cell carcinoma

The dermoscopic features of nonpigmented basal cell carcinoma include:

• Bluish or whitish-pink stroma
• Asymmetrical branching serpentine (arborising) vessels
• Focal ulceration
• Slight scaling
• White clues, particularly perpendicular white lines (polarised light only) and structureless roundish white or yellowish areas.

On close inspection, some apparently non-pigmented basal cell carcinomas have a lightly pigmented stroma.

Nodular basal cell carcinomas lose the blue hue and instead may have a white rim around central ulceration. White clods (milia-like cysts may be present.

Prominent polarised perpendicular white lines, pink stroma, branched red lines

Prominent blood vessels, polarised white lines, and yellowish clods

Erosions, light-brown stroma, serpentine vessels, polarised white lines

Dermoscopic features of nodular basal cell carcinoma

The dermoscopic features of nodular basal cell carcinoma include:

• Arborising vessels (branched red lines)
• Blue-grey ovoid nests (large clods)
• Ulceration
• Peppering (grey or brown dots) and or clods.

Skin coloured to pinkish stroma, blue structures, branched red lines, and polarised white structures.

Pinkish stroma, light brown peripheral converging pigment, grey and blue dots, irregular branched red lines, and few polarised white lines

Ill-defined borders, skin coloured stroma, branched red lines, prominent polarised white lines

Pink to purple stroma, prominent irregular vessels, greyish clods, prominent polarised white structures

Central ulceration, ill-defined pinkish stroma, few short vessels, solitary bluish structure, and polarised white lines

Ill-defined margins, light brown stroma, concentric brown structures, branched red lines

Light brown stroma, prominent irregular branched vessels, and polarised white lines

Peripheral converging deeply pigmented oval or 'leaf-like- structures, ulceration, and white polarised lines

Well-defined lesion with brown stroma, darker peripheral 'leaf-like' areas (pigment converging inwards), and ulceration

Dermoscopic features of superficial basal cell carcinoma

The dermoscopic features of superficial basal cell carcinoma include:

• Short fine telangiectases
• Perpendicular white lines (polarised light only)
• Ulceration and adherent fibre
• Leaf-like areas (brown to grey-blue discrete bulbous blobs that often form a pattern shaped like a leaf; they can sometimes appear as tan, broad, and fuzzy streaks at the periphery of a lesion)
• Absence of blue-grey ovoid nests, arborising vessels and ulceration
• Multiple small erosions
• White, red structureless areas (milky pink areas)
• Shiny white to red areas.

Irregular lesion with pink background, superficial erosions, peripheral pigmented structures, peppering, polarised white lines

Red irregular patch with short linear vessels, some red dots, and polarised white perpendicular lines

Irregular red background with multiple erosions and polarised white structures

Irregular lesion with peripheral pigmented radial lines converging on nonpigmented central area, concentric pigmented clods, polymorphous vessels.

Large irregular pink plaque with scattered light brown concentric and short linear structures with prominent polarised white structures

Irregular pinkish lesion with erosions, short red vessels, erosions, polarised white structures

Dermoscopic features of morphoeic basal cell carcinoma

The dermoscopic features of morphoeic basal cell carcinoma include:

• A predominant white structureless scar-like area with a few fine branching serpentine vessels and multiple brown dots
• Sometimes vessels are the only clue.

Nasal tip lesion with whitish background, some preservation of follicular plugging and sebaceous hyperplasia

White lesion with irregular branched vessels

White irregular lesion with polarised white structures

What is the dermoscopic differential diagnosis of basal cell carcinoma?

Differential diagnoses for basal cell carcinoma are:

• Sebaceous hyperplasia
• Melanoma
• Pilomatricoma
• Trichoepithelioma.

Sebaceous hyperplasia dermoscopy

Amelanotic melanoma dermoscopy

Pilomatricoma dermoscopy

Trichoepithelioma dermoscopy

What is the histological explanation of features of basal cell carcinoma?

Below are histological explanations for the features of basal cell carcinoma.

Sharply defined fine linear and branching serpentine vessels

Thickening of the epidermis causes dilated papillary dermal blood vessels (which usually appear as red dots) to be drawn out to form sharply defined fine linear and branching serpentine vessels. They sit close to the surface of the skin.

Leaf-like areas

Leaf-like areas are brown to grey-blue discrete bulbous blobs that form a pattern shaped like a leaf and are caused by nodules of pigmented basal cell carcinoma cells in the upper dermis.

Large blue ovoid nests

Large blue ovoid nests are also known as large blue clods and are created by nests of basal cell tumour in the dermis.

Multiple blue clods

Blue clods are formed by nests of basal cell tumour in the dermis.

Specks of brown and grey pigment

Specks of brown and grey pigment are formed as follows:

• Grey dots are due to melanin pigment within the papillary dermis, either free, in small nests of melanocytes or, more commonly, in melanophages
• Brown dots reflect either small nests of melanocytes in the basal epidermis, focal pigmented keratinocytic proliferation, as seen in some forearm solar lentigines or superficial dermal haemosiderin deposition.

Spoke wheel areas

Spoke wheel areas are also known as radial projections joined at a central hub and are formed by nests and proliferation of pigmented basal cell carcinoma cells.

Perpendicular white lines

Perpendicular white lines are thought to be caused by fibrous tissue.