Pigmented lesion on upper lip.

A 32 year-old woman consulted for this pigmented lesion present for 6 months.

Dermoscopy revealed:

• an atypical pseudonetwork
• rhomboidal structures
• irregular globules

A melanoma was suspected and this lesion was excised. Pathology revealed a superficial spreading melanoma in situ (Clark level I).

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

Strawberry appearance

Facial non pigmented actinic keratoses (AKs) display 4 main dermoscopic features:

1. erythema, with a pink-to-red pseudonetwork surrounding the hair follicles
2. white-to-yellow surface scale
   
3. fine, linear-wavy vessels surrounding the hair follicles
   
4. hair follicle openings filled with yellowish keratotic plugs and/or surrounded by a white halo
   

These features combined to produce a strawberry’ appearance.

Strawberry appearance in a non pigmented AK

Strawberry appearance in a slightly pigmented AK

Other cases of AKs:
1

Literature:
I. Zalaudek, J. Giacomel, G. Argenziano, R. Hofmann-Wellenhof, T. Micantonio, A. Di Stefani, M. Oliviero, H. Rabinovitz, H.P. Soyer, K. Peris (2006) Dermoscopy of facial nonpigmented actinic keratosis. British Journal of Dermatology 2006: 155 (5) , 951–956

Scar lentigo

This 52-year-old man was operated 4 years before of a benign nevus of the lumbar area. The lesion was completely excised and pathologist concluded to a jentigo. 4 years after he consulted for this pigmentation appearing on two places of the scar. Dermoscopy revealed a faint pseudo-network of light-brown color with a moth-eaten border which was in favor of a scar lentigo. There were no signs of recurrence of a nevus or a melanoma. A follow-up was proposed.

References:
1 - D.Weedon, Skin Pathology, second edition, p 822
2 - Melanotic pigmentation in excision scars of melanocytic and non melanocytic skin tumors. Botella-Estrada et al. J Cutan Pathol 1999 Mar; 26(3):137-44

Spitz nevus

5-year-old boy with pink tumor on his right cheek clinically in favor of a Spitz nevus.
Dermoscopy revealed a non specific regular pseudo-network with a granular appearance.
Dermoscopy criteria are useful for pigmented Spitz nevi or Reed nevi.
In this case, a regular 6-months follow-up was proposed.

Pseudonetwork

A 52-year-old woman consulted for a pigmented lesion of her nose. This lesion was biopsied and pathology revealed an actinic keratosis.
The dermoscopic feature was a pseudonetwork.
The dilated follicular openings seen on the facial skin create a false broadened network or pseudonetwork that can be observed in various benign pigmented lesions as ephelide (freckle), actinic lentigo, actinic keratosis and junctional nevus.