A pigmented lesion

A 32-year-old man had his moles checked up.

Dermoscopy revealed:

• whitish globules  / white cobblestone pattern
• Light-brown peripheral network

 In favor of an accessory nipple

Central white cobblestone pattern

 Reference:

Dermoscopy of accessory nipples in authors’ own study 

G. Kamińska-Winciorek, J. Szymszal, W. Silny

Postep Derm Alergol 2014; XXXI, 3: 127–133

A 28-year-old patient consulted for this pigmented lesion on his right forearm.

Dermoscopy revealed:

• multiple patches of pigmentation
• without background pigmentation

Clinical and dermoscopic examination were in favor of an agminated nevus.

Differential diagnosis is nevus spilus: this one includes a tan background patch which is not present in agminated nevus.

A third nipple.

A 28-year-old man consulted for this pigmented lesion located under his nipple. He was thinking this lesion was present since birth.

Dermoscopy revealed a central hypo-pigmented area with a peripheral pigmented reticulation.
This feature looks like a dermatofibroma

This lesion was a surnumerary nipple (accessory nipple)


References:
1 - Blum A., Roehm S. Accessory nipple looks like dermatofibroma in dermoscopy. 
Arch Dermatol 2003 Jul; 139 (7): 948-9


2- Oztas MO, Gurer MA. Dermoscopic features of accessory nipples. Int J Dermatol 2007; 46(10):1067-8

Solar lentigos

Case 1: clinical image

The clinical aspect of a solar lentigo* is a light brown macule.
(* other denominations: lentigo actinica, senile lentigo)

Case 1: dermoscopic image

2 types of patterns can be observed:

• reticular pattern with regular meshes and thin lines
• homogeneous pattern

In all cases, the pattern has a sharp demarcation and a light brown to tan colour.

Case 2: dermoscopic image

In the 2nd case, the moth eaten borders are one of the typical aspects of solar lentigos.

Another dermoscopic feature sometimes observed is fingerprint-like structures.

Other cases: 1

Atypical (dysplastic) nevi

A 19-year-old man consulted for multiple atypical (dysplastic nevi or Clark nevi) on her trunk. Three of them were clustered on her back. They featured three different dermoscopic patterns:

1-reticulo-globular pattern with eccentric hyperpigmentation

2 - multicomponent pattern (globular, reticular and homogeneous patterns)

3- reticular pattern with central hypopigmentation

Collision tumor

A patient presented a pigmented lesion on his back (lumbar area). He had no idea of change of colors or size and this lesion had not been traumatized.

Picture taken with a Fotofinder dermoscope

Dermoscopy revealed a peripheral reticular-globular pattern with a central hypopigmentation in favor of a benign melanocytic nevus.

Picture taken with a 3Gen Dermalite Foto System Pro

At the inferior pole of the lesion, a red structureless area was noticed in favor of a cherry angioma.

The association of these to lesions, namely melanocytic nevus and cherry angioma corresponded to a collision tumor.

Picture taken with a Fotofinder dermoscope

Picture taken with a 3Gen Dermalite Foto System Pro

A collision tumor is defined as a side-by-side occurence of two tumors (benign or malignant).

For example: confluence of a seborrheic keratosis and a basal cell carcinoma, confluence of a melanoma and a BCC, confluence of an angioma and a Clark nevus.

Hypopigmentation

Hypopigmentation is a very common sign seen in atypical nevi (dysplastic nevi) .
Hypopigmented areas are devoid of structures, lightly pigmented, and comprise at least 10% of the surface area. Hypopigmented areas are sometimes observed around follicles in common nevi and congenital nevi.
In atypical nevi, these areas are located centrally whereas in melanomas they are most often seen at the periphery.

Case 1: central hypopigmentation and peripheral reticular pattern in an atypical nevus

Case 2: multiple areas of hypopigmentation and reticular pattern in an atypical nevus

Case 3: patchy multifocal hypopigmentation in an atypical nevus


Case 4: hypopigmented areas around follicles in a melanocytic nevus

Dysplastic nevus

A 34-year-old woman presented a Clark nevus (synonyms: atypical nevus or dysplastic nevus) on her back.


Dermoscopy revealed an asymmetric reticular-globular pattern.


Central globular pattern (circle) and reticular pattern (rectangle) are well seen on this picture.
The reticular-globular pattern is the most frequent of the different patterns observed in Clark Nevi.

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  

Compound melanocytic nevus

A 14-year-old girl consulted for an enlarging melanocytic nevus on her back. One of her sister, aged 24, had been operated for a superficial spreading melanoma 2 years before, and she was very anxious. The lesion was larger than 6 mm and had an irregular border.


Dermoscopy revealed a central homogeneous pattern and a peripheral typical reticular pattern, and peripheral globules, but no signs for a SSM.
The lesion was removed and pathology was in favour of a compound melanocytic nevus.

Nevus spilus

A 25-year-old woman consulted for a pigmented lesion on her right arm.
The lesion was a lentiginous patch with darker brown pigmented macules in favor of a nevus spilus.
Dermoscopy revealed darker brown areas with a reticulo-globular pattern in favor of melanocytic nevi. The background was light brown and reticular.

Nevus spilus are present at birth or childhood. On histology they correspond to a lentigo with surimposed junctional or compound nevi.
Main differential diagnosis is agminated nevus which correspond to lentiginous compound melanocytic nevi without light background pigmentation.

Reference: Bragg et al. Agminated acquired melanocytic nevi of the common and dysplastic type. J Am Acad Dermatol 2005;52:67-73

Collision tumor

A 57-year-old man consulted for a bi-coloured lesion on his back.



Dermoscopy revealed a typical reticular pattern and some brown globules (red circle) in favor of a melanocytic nevus and a lighter brown pigmentation (green circle) without pigment network. Delicate fat fingers were present on this part in favor of a seborrheic keratosis.

The lesion was excised and pathology confirmed the diagnosis of collision tumor which associated a seborrheic keratosis and a melanocytic compound nevus.

A collision tumor is defined as a side-by-side occurence of two tumors (benign or malignant). For example: confluence of a seborrheic keratosis and a basal cell carcinoma, confluence of a melanoma and a BCC, confluence of an angioma and a Clark nevus.

Congenital nevus

A 12-year-boy consulted for the follow-up of a congenital melanocytic nevus on his abdomen.

Dermoscopy revealed a typical reticular pattern and regular globules.

Atypical nevus

This patient presented an atypical nevus with a reticular pattern and a central hypopigmentation.

Definition of atypical (dysplastic) nevus: nevus characterized by a diameter > 6mm, color variegations, and irregularity of the border. They have 3 global dermoscopic patterns, namely reticular, globular and homogeneous. Different combinations are possible, the reticular-globular one is the most frequent.

Patchy multifocal hypopigmentation

Congenital melanocytic nevus: reticulo-globular pattern, and patchy multifocal hypopigmentation (peri-follicular hypopigmentation)

Atypical (dysplastic) nevus with central hypopigmentation

This atypical (dysplastic) nevus was localized on the back of a 37-year-old man.
Dermoscopy revealed a reticular pattern with central hypopigmentation. Frequently the less pigmented centre corresponds to clinical papule (fried-egg type atypical nevus)

Eccentric hyperpigmented area

This pigmented lesion was asymetrically pigmented. Dermoscopy revealed a globular pattern in the center and a reticular pattern at the periphery with an eccentric hyperpigmented area (circle)
There were no dermoscopic criteria for a melanoma. We have to be very careful with this dermoscopic feature of eccentric hyperpigmented area because it is observed in atypical nevus but also in melanoma in situ and early invasive melanoma. Two attitudes could have been proposed: 3-month dermoscopic follow-up or immediate excision. In our case we choose to cut it off and pathology revealed a benign compound nevus (dermal and junctional