Are You Confident of the Diagnosis?
Characteristic findings on physical examination
Nevus of Ito is similar to nevus of Ota from both a pathologic and pathophysiologic perspective. It differs mainly in its distribution. Nevus of Ito most commonly is seen overlying the distribution of the posterior supraclavicular and cutaneous brachii lateralis nerves. The lesions usually present at birth as blue-brown macules ranging from the upper chest to the shoulder and sometimes extending onto the upper arm. Additionally, there is an acquired variant seen in Asian women between aged 19-69.
Expected results of diagnostic studies
Histology will show elongated dendritic melanocytes scattered among collagen bundles in the upper part of the reticular dermis. As is the case with nevus of Ota, these lesion are more cellular than are biopsies taken from lesions of dermal melanocytosis.
Who is at Risk for Developing this Disease?
Similar to nevus of Ota, nevus of Ito is most commonly seen in individuals of Japanese descent, but it can also be seen in individuals of African and East Asian descent. Lesions may also be seen in association with nevus of Ota, but is thought to be overall much less common.
What is the Cause of the Disease?
Similar to nevus of Ota and dermal melanocytosis, nevus of Ito results from a failed migration of melanocytes from the neural crest to the basal layer of the epidermis, leaving them in the reticular dermis.
Systemic Implications and Complications
There are no systemic implications or complications associated with nevus of Ito.
Since the histology is identical to nevus of Ota, the same types of therapies have been tried for nevus of Ito. These include a variety of different lasers with the Q-switched ruby laser considered to be the most effective by some authors. Overall, there are many fewer case reports on the treatment of nevus of Ito, mainly because its location arouses less cosmetic concern.
Optimal Therapeutic Approach for this Disease
Reassuring the patient that this is only a lesion of only cosmetic concern is of paramount importance. Should treatment be desired, laser treatment, preferably with the Q-switched ruby laser, may be recommended.
Since nevus of Ito is benign, has no known systemic associations, and occurs in a nonworrisome location from a cosmetic perspective, no work-up, follow-up, or treatment is necessary. Although the development of a melanoma in a nevus of Ito is an extrarodinarily rare event, should any suspicious changes occur within the lesion, a biopsy should be performed.
Unusual Clinical Scenarios to Consider in Patient Management
To date, there have been two cases of melanoma associated with a nevus of Ito. Therefore, any suspicius clinical change in a nevus of Ito should be biopsied.
What is the Evidence?
Raulin, C, Schonermark, MP, Greve, B. “Q-switched ruby laser treatment of tattoos and benign pigmented skin lesions: a critical review”. Ann Plast Surg. vol. 41. 1998. pp. 555-65. (An excellent review of the efficacy of the Q-switched ruby laser in the treatment of several different pigmentary disorders, including nevus of Ito, as well as tattoos. Many authors, including this group, consider the Q-switched ruby laser to be the most effective laser for the treatment of pigment in the dermis, such as is the case with nevus of Ito.)
Wise, SR, Capra, G, Martin, P. “Malignant melanoma transformation within a nevus of Ito”. J Am Acad Derm. vol. 62. 2010. pp. 869-74. (This case report describes the second reported case of malignant melanoma arrising in a nevus of Ito. Approximately 10 cases of melanoma have been described in assocation with nevus of Ota, including several cases of ocular melanoma.)
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