Melanonychia in a Six Year-Old Child

Presented by
Dr. Chee Meng Loh
RMG
Singapore
E mail: bliss88@singnet.com.sg

The patient is a six year old Chinese girl who developed a dark pigmented longitudinal band on the nail of her right index finger about 1 year ago. It started as a narrow, light brown band and grew in darkness (black in centre of band, and lighter shade of brown at edge of band) and width. The band is now about 3 mm in width. It has not changed in the past 3 months.

There is no history of trauma to the right index finger. There is also no complaint of pain in that finger.

The girl suffers from eczema and is on steriod medication (hydrocortisone 1% cream). She is otherwise healthy. There is no history of melanoma in the girl, her parents or grand parents. Neither her parents have pigmented bands on their nails.

Physical Exam: Dark longitudinal pigmented band on right index finger.
Colour ranges from black to brown.
Width is about 3 mm.
(Pictures attached)

Biopsy not performed.

Diagnosis: Melanonychia of right index finger.

Questions:
What are the likely causes of melanonychia in this child?
What is the likelihood that the cause is melanoma?
Should biopsy be performed to rule out melanoma?
If yes, what biopsy procedure is appropriate and what is the risk of permanent damage to the nail?
If a wait and see approach is appropriate, what other signs should the parents watch out for and within what time frame?

Melanonychia
Originally uploaded by David Elpern.

Melanonychia
Originally uploaded by David Elpern.