Lattice-like pattern

A 14-year-old girl consulted for this small plantar nevus.

Dermoscopy revealed a typical lattice-like pattern which is a subtype of parallel furrow pattern in favour of a benign acral plantar nevus.

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11  

Acral melanocytic nevus

A 48-year-old woman consulted for this pigmented lesion on her 5th right finger present since early childhood. 

Dermoscopy revealed a parallel furrow pattern and in some areas a lattice-like pattern.

The dermoscopic features were in favor of a benign acral nevus.

A regular yearly follow-up was planned.

In parallel furrow pattern, the pigmentation follows the sulci at the difference of parallel ridge pattern where the pigmentation follows the cristae.

In Acral melanocytic nevi, 3 types of patterns can be observed:

• parallel furrow pattern
• lattice-like pattern
• fibrillar pattern

Parallel ridge pattern are typical of acral melanomas but can be observed in other cases:

• milk-line nevus
• subcorneal hemorrhages (talon noir)

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11  

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  

Fibrillar pattern

A 35-year-old woman consulted for a pigmented lesion on the sole of her left foot.
The dermoscopic feature was typical of a fibrillar pattern.
The fibrillar pattern was uniform and localized on the entire surface of the lesion. That was in favor of a benign acral melanocytic nevus.

The fibrillar pattern is a subtype of parallel furrow pattern observed on high-pressure areas and in hyperkeratotic areas.
Fibrillar pattern are quite never observed on palmar surface.
It has to be reminded that fibrillar pattern is in favor of a benign acral nevus only if it occupies the whole surface of the lesion. Melanomas can dysplay a fibrillar pattern in focal areas in a disorganized manner.

Reference:
Braun RP, Kopf AW, Marghoob AA. Comment on dermoscopy patterns of melanocytic nevi on the sole. J Am Acad Dermatol 2006; 55: 162-3

Other cases of fibrillar pattern: 1 2 3

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11  

Blotch

Blotch (or black lamella) is a black or dark brown pigmentation.
Blotch is formed by a large quantity of melanin pigment in the epidermis and / or dermis.
Here is a case of melanocytic junctional nevus where a blotch is covering its largest area.
In malanomas, blotches are often irregular.

Fibrillar pattern

A 48-year-old woman noticed a pigmented lesion on the right side of her right foot.
Dermoscopy revealed a fibrillar pattern in favor of a benign acral melanocytic nevus.

Fibrillar pattern is a variant of parallel furrow pattern.

Acral melanocytic nevus

A 6-year-old boy consulted for a congenital acral melanocytic nevus on his 2nd left toe.


This lesion exhibited a combination of 3 patterns, namely a parallel furrow pattern (dots on the furrows), an homogeneous pattern and a reticular pattern.


Parallel furrow pattern (circle) and reticular pattern (rectangle) were the main patterns observed on this benign melanocytic nevus.

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11  

Acral melanocytic nevus with a globular pattern

Acquired or congenital benign melanocytic lesions on the palms and soles (volar skin) are usually called acral nevi.
Acral melanocytic nevi typically feature the following aspects: parallel furrow pattern, lattice-like pattern and fibrillar pattern.

A 25-year-old man consulted for a congenital melanocytic nevus located on the right plantar arch.


Dermoscopy featured a globular pattern without signs of parallel pattern.

White dots

Typical case of benign acral melanocytic nevus.

Parallel furrow pattern.


Eccrine pores are well recognized as white dots which are located on the ridges between the furrows

Parallel furrow pattern

Pigmented nevus on the 5th right toe. Parallel furrow pattern in favor of a benign acral melanocytic nevus. Blue-white color in some areas correspond to the dermal production of melanin by nevus cells. No excision was required for this benign nevus.

Parallel furrow pattern

A 3-year-old boy consulted for this congenital nevus on his 4th right toe. Dermoscopy revealed a parallel furrow pattern. An annual follow-up was scheduled.

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11  

Parallel furrow pattern

A 18-year-old man consulted for 3 palmar nevi. Dermoscopy showed typical parallel furrow patterns in favour of benign acral nevi

Fibrillar pattern

This patient presented a benign acral melanocytic nevus with a typical fibrillar pattern

Acral melanocytic nevus

A 39-year-old woman (phototype V) noticed a pigmented lesion on her 5th left toe.
Dermoscopy revealed a uniform black homogeneous pattern with whitish dots (eccrine pores) and some streaks.
The lesion was excised and pathology revealed a compound melanocytic nevus.

Other cases of acral nevi:

1  2  3  4  5  6  7  8  9  10  11  

Recurrent nevus

A 25-year-old man consulted for pigmented patches that had appeared 2 years before around a plantar scar. The scar was due to the former excision of a benign acral plantar melanocytic nevus when he was 14-year-old.
Dermoscopy revealed a relatively symmetric centrifugal pattern from the center of the scar (*). The centrifugal pattern of the pigmentation, and the absence of many dermoscopic structures and colors were in favor of a benign recurrent nevus. A 3-month follow-up was proposed and in case of enlargement a new excision would be scheduled.

Parallel furrow pattern

Dermoscopy of this pigmented plantar lesion reveals a typical furrow pattern in favor of a benign melanocytic nevus

Fibrillar pattern

A 56-year-old woman presented a plantar nevus on her right foot, located on the lateral area. Dermoscopy revealed a typical fibrillar pattern (or filamentous pattern).