The Cobblestone Nevus: A Thing of Beauty

The patient is a 30 year-old woman in the 14th week of her first pregnancy.  Her obstetrician asked her to see a dermatologist regarding a congenital nevus.  She has noticed only slight change in the past decade.

O/E: There is a 3.0 cm bosselated nevus over the right costal margin.  Some of the facets vary in color.

Clinical + Dermatoscopic Images:

Diagnosis: Congenital Nevus with a bosselated (pebbly, cobblestone) appearance.  Does anyone have a comment?  Presented for comments and to share the beautiful dermatoscopic appearance.  Am I missing something?

Plan:  I will reevaluate after she delivers.

Dermatoscopic Dilemmas

The dermatoscope is a source of endless wonder.  Here are two cases seen in the past week.

1. Congenital Nevus of Special Site

This 5 month old bi-racial (Black/Caucasian) foster infant was noted to have a slowly enlarging pigmented lesion in his left crural fold since around one month of age.

photo taken by Dr. Yoon Cohen

Question/Comment: Would anyone do anything other than follow this child?  Is the gray veil significant? The symmetrically distributed brown clods are to my mind markers for a benign growing nevus (cobblestone pattern).  There is no pertinent literature about growth in small congenital nevi.  Melanoma, in this age group and ethnicity, is exceedingly rare.

2. Unusual Subungual Hematoma

A 72 yo woman noted nail pigmentation that appeared shortly after knee replacement surgery.  I do not know if she had been anticoagulated after surgery, but the information would help.  The subungual color under the cuticle may be an example of a "pseudo-Hutchinson sign."

1 month follow-up

Note:  The one month follow-up shows distal progression of pigmented area confirming the clinical impression of subungual hematoma.

Question/Comment: The fact that this appeared shortly after surgery strongly suggests trauma rather than neoplasia.  If the patient was anticoagulated during surgery, that would be one more helpful historical fact.  The pattern of the long band could be called the "tadpole sign" -- I wonder if it is specific for subungual hematoma.

References:
1. Precursors to melanoma and their mimics: nevi of special sites.

Elder DE. Precursors to melanoma and their mimics: nevi of special sites. Mod Pathol. 2006 Feb;19 Suppl 2:S4-20.  Free Full Text.

2. Dermnet.nz.org has good sections on dermtoscopy: Introduction to Dermatoscopy   Dermatoscopic Features 

3. Overview of Nail Dermatoscopy

Complicated Speckled Lentiginous Nevus

Presented by Yoon Cohen, D.O.
Alta Dermatology
Mesa, Arizona

Abstract: An 8-year-old girl with large congenital nevus on the chin, the anterior neck and the right aspect of shoulder and the chest

History: The patient is an 8-year-old girl who was born with congenital nevi on the mid anterior neck and possibly another similar lesion over the right side of the mandible. Over the years, she has developed many 1-3 mm in diagmeter tan papules in and around the chin and submental region. She was seen recently for follow up. Her nevus is slowly maturing but still benign in appearance and there are no outlier lesions in the large defect. Some of the tumor is bilateral.

Clinical photo:

O/E: The skin examination shows a healthy, pleasant child with numerous scattered 1 to 3 mm brown macules and papules in a background of light tan pigmentation on the chin, the anterior neck and the right aspect of the upper chest. There is a well marginated 25 mm in diameter brown patch on the lower mid anterior neck. There is a 3.5 x 4.0 cm hypopigmented patch on the right shoulder

Diagnosis: Complicated Speckled Lentiginous Nevus (SLN)

Questions: Please share your experiences in managing patients with SLN similar conditions.  Do you feel there is a concern that this lesion may undergo malignant transformation.  What do you think of the hypopigmented area?

Discussion: A speckled lentiginous nevus (SLN, Nevus Spilus) can be a congenital or acquired pigmented lesion. More recently arguments are in favor of speckled lentiginous nevi as subtype of congenital nevi including the following observations: frequent presence at birth or noted soon therafter; patterns of distribution reflecting embryonic development; hamartomatous behavior with various types of nevi; and histologic features of congenital melanocytic nevi within the lesions. There are two types of speckled lentiginous nevus -- Nevus spilus maculosus and nevus spilus papulosus. The macular type is characterized by dark speckles that are completely flat and rather evenly distributed on a light brown background, resembling a polka-dot pattern. In contrast, nevus spilus papulosus is defined by dark papules that are of different sizes and rather unevenly distributed, reminiscent of a star map. Perhaps, the most pressing concern is its potential malignant transformation. The propensity to develop Spitz nevi appears to be the same in both types of speckled lentiginous nevus whereas the development of malignant melanoma has been reported far more commonly in nevus spilus maculosus. Torchia and her colleague argue that malignant transformation of melanocytes might occur in SNL not because the hyperpigmented background features any specific procarcinogenic abnormality but because there are more melanocytes with SNL, yielding a slightly higher likelihood of developing any type of melanomcytic lesion. It is our best interest that we monitor our patients with SNL pediodically to detect any early signs of malignant transformation.

References:
1. Happle R. Speckled lentiginous naevus: which of the two disorders do you mean? Clin Exp Dermatol. 2008;34:133-135
2. Paraskevas LR, Halpern AC, Marghoob AA. Utility of the Wood's light: five cases from a pigmented lesion clinic. Br J Dermatol. 2005 May; 152(5): 1039-44
3. Menon K. Dusza SW, Marghoob AA, et al. Classification and prevalence of pigmented lesions in patients with total body photographs at high risk of developing melanoma. J Cutan Med Surg. 2006 Mar-Apr; 10(2):85-91
4. Schaffer J. Orlow S, Lazova R, et al. Speckled Lentiginous Nevus Within the Spectrum of Congenital Melanocytic Nevi. Arch Dermatol. 2001; 137:172-78
5. Torchia D. Schachner L. Is speckled lentiginous nevus really prone to dysplasia/neoplasia? Pediatr Dermatol. 2012 Jul-Aug; 29(4):546-7

Comments:
1. Dr. Ashfaq Marghoob: 
These patients (SLN of maculosa type) are at slightly higher risk for developing MM. Continued surveillance for focal change is what I do for these patients.

2. Dr. Rudolph Happle:
Thank you very much for letting me see this interesting case! Apparently, this is a classical example of papular SLN (papular nevus spilus).  Why is your diagnosis "Complicated SLN"? I would call this a complicated case if a melanoma would develop, but the risk is rather low because It's not a macular nevus spilus.

3. Dr. Harper Price: 

Thank you for sharing this interesting case.  It does look very classic for a SLN.

The risk of malignant transformation is very low and likely starts at puberty so I would follow her yearly and if there was a lot of change, even more frequently and use photography to help.  These SLN can have many other nevi within in as stated, including Spitz and blue nevi.

Hers looks quite good and not worrisome.  The area of hypopigmentation, if new, may represent vitiligo or if present early on, a hypochromic nevis (“twin spotting”).

These SNL certainly carry a much lower risk than a typical congenital melanocytic nevus of this size for melanoma development. 
Lifelong follow-up is my recommendation