A pigmented labial lesion

A 24-year-old woman consulted for a pigmented labial lesion.

Dermoscopy revealed multiple curves of semicircle, U or V mimicking the scales of a fish.

This fish scale-like pattern was in favor of a mucosal melanotic macule.

Fish scale-like pattern

Fish scale-like pattern is a new pattern described in mucosal melanotic macules.

Reference: 
Dermoscopy of pigmented lesion on mucocutaneous junction and mucous membrane.
Lin J, Koga H, Takata M, Saida T. 
BJD 161 (6); 1255-61

Actinic lentigo

A 72-year-old man consulted for an enlarging pigmented lesion on his right hand. This lesion was quite typical of an actinic lentigo.

Dermoscopy confirmed easily this diagnosis showing: a homogeneous pattern and a pseudoreticular network with thin lines,  with a moth-eaten border

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.

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