Porokeratosis (Mibelli)

A 63-year-old woman consulted for this brown-red annular plaque on her right leg. This lesion had been slowly expanding for 2 years. The lesion was slightly hypopigmented in its center. Palpation at the periphery revealed a raised annular border.
The clinical examination was in favor of a porokeratosis (Mibelli)

This diagnosis of porokeratosis was easily confirmed with dermoscopy.


The dermoscopic aspect of porokeratosis is a "white track" structure with a brown pigmentation visible in the inside of the track.
This white tract structure corresponds to the cornoid lamella.
In the central part of the lesion, dermoscopy may feature a white area, red dots, globules and lines corresponding to vessels.

Reference: P.Zaballo, S. Puig, J. Malvehy. Dermoscopy of disseminated superficial actinic porokeratosis. Arch Dermatol 2004; 140: 1410

Basal cell carcinoma

A 72-year-old woman consulted for this pigmented lesion on the left side of her nose.

Dermoscopy revealed a non melanocytic tumor with:

• large blue ovoïd nest
• arborizing vessels (in the blue ovoïd nest)
• blue gray globules
• leaf-like areas

in favor of a basal cell carcinoma.

leaf-like structures

Other cases of basal cell carcinomas: 

1 2 3 4 5 6 7 8 9  10 11 12 13 14 15 16 17 18 19 20 21

Labial lentigo

A 15-year-old girl consulted for this acquired pigmented lesion on her lower lip.
This lesion was solitary.

Dermoscopy revealed a pigmentation with a parallel pattern of light-brown to dark-brown streaks which were linear or curvilinear.

This dermoscopic presentation was quite typical of lentigos of the mucous membranes.

We must note that melanoma-specific criteria (atypical pigment network, irregular dots and globules, blue-white veil etc...) are not found in benign lentigos of the oral and genital mucous membranes.

In our case, a biopsy was performed and confirmed the diagnosis of benign labial lentigo.

Arborizing tree vessels

A 79-year-old woman consulted for this lesion near her right ear. This lesion was soft and non ulcerated. The patient did not remember how long it was evolving.

Dermoscopy revealed a homogeneous pattern with many arborizing vessels.

The lesion was excised and pathology was in favor of a benign melanocytic nevus


Arborizing vessels are mainly found in basal cell carcinomas and also rarely in the following lesions:

• melanocytic nevus
• melanoma
• seborrheic keratosis
  

Superficial spreading melanoma

A 66-year-old man consulted for a pigmented lesion on his left scapular area.

Dermoscopy revealed a multi-component pattern, asymmetry, and multiple colours (tan, dark brown, black, blue gray, white).
Other signs were an atypical reticular pattern (irregular holes and thick lines) with a sharp demarcation, a blue-white veil and atypical vessels (irregular linear vessels), a central ulceration (crust). Dots were irregularly distributed.

All these dermoscopic signs were in favor of a superficial spreading melanoma.

Lattice-like pattern

A 17-year-old girl consulted for an acral melanocytic lesion on her left toe.



Dermoscopy revealed a lattice-like pattern in favor of a benign acral melanocytic nevus.

Lattice-like pattern is a subtype of parallel furrow pattern.
It is more often localized on arch areas at the difference of fibrillar pattern which is observed more frequently on pressure areas.

On this figure above, the lattice-like pattern corresponds to the longitudinal and transversal thicker lines and the white circles symbolize eccrine pores.

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11