What is nevus Ito? Nevus of Ito is a hamartoma of deeply pigmented dendritic dermal melanocytes.
Nevus of Ito lesions are very similar to Ota lesions. The only difference is the location of the macule. The Ota and Ito macule melanocytes are more superficially located than in the Mongolian spot. These lesions are usually on one side of the face (unilateral), but in some rare cases they appear on both sides (bilateral). In some cases both Ota and Ito lesions may be present in the same individual. Amiya Kumar Mukhopadhyay reported a very rare case of simultaneous occurrence of unilateral Ota lesion, bilateral Ito lesion and palatal lesions in a male patient.
These macules are mostly congenital and their rate of prevalence among different populations suggests genetic influences. Ito macules are predominant in Asian and African races. Mataix J et al (J Cutan Pathol. 2007 Aug;34(8):640-3) reported a case of an uncommon acquired Ito lesions in a Caucasian elderly woman. Their proximity to nerve bundles and sensory disturbances indicate an unknown factor connected to the nervous system. It is possible that the rate of incidence may be much higher, as there are less cosmetic concerns, the prevalence may be underreported.
Nevus of Ito manifestationsNormally the Ito lesions do not show any apparent sensory disturbances. M. Ito reported that
"slight gradial and chronometrical differences in local sweating than surroundings and the late development of erythema and wheal in histamine scratch test rather than normal skin were noticed". These lesions may have scattered intralesional flecks and freckles. The color variations of the lesions include blue, grey, slate and brown. The color variations of the lesion is due to Tyndall effect of the dermal melanocytes. The blue and brown color variation may also be indicative of the mesodermal and ectodermal origin of the dendritic cells.
Nevus of Ito and the dermal pigmentation results from the entrapment of dendritic cells derived from melanoblasts in the dermis. Dermal melanocytes synthesize melanosomes. Though they appear to have dendrites, they do not transfer melanosomes to surrounding cells. Possibly these dermal melanocytes retain, degrade and replace these melanosomes periodically. The overlying epidermis is normal.
Nevus of Ito treatment and managementCosmetic camouflage makeup and topical therapy is of no value as these lesions are not apparent. If the patient insists on treatment, other treatment options include dermabrasion, chemical peels, topical bleaching, dry ice vaporization and electrodessication. QYAG5 Q-switched Nd:YAG Laser surgery is the current treatment of choice. There is excellent improvement in a majority of the patients and there are no significant adverse effects.
Nevus of Ito and malignant melanomaonly a few clinical cases of malignant transformation into melanoma of Ito lesions have been reported. Martínez-Peñuela A et al. (Actas Dermosifiliogr. 2011 Dec;102(10):817-20) reported a case of malignant melanoma arising from Ito lesions. A 24 years old patient had developed a subcutaneous nodule in the anterolateral region of the thorax. The nodule was located beneath a faint blue-gray macule. Excising the nodule revealed a densely cellular tumor with characteristics of malignant melanoma. Diagnostic studies confirmed malignant melanoma. The surrounding skin composed of smaller, very pale grayish-blue macules which were diagnosed as Ito lesions. The case history of the patient revealed that the lesion had been present since childhood. Hence, it is safer to keep monitoring the Ito macules for any form of change.
1.Amiya Kumar Mukhopadhyay. Unilateral Nevus of Ota with Bilateral Nevus of Ito and Palatal Lesion: A Case Report with a Proposed Clinical Modification of Tanino's Classification. Indian J Dermatol. 2013 Jul-Aug; 58(4): 286–289.
2.Sanjeev Aurangabadkar. QYAG5 Q-switched Nd:YAG Laser Treatment of Ota: An Indian Study of 50 Patients. J Cutan Aesthet Surg. 2008 Jul-Dec; 1(2): 80–84.
3.Minor Ito. Studies on Melanin XXII. Nevus Fusco-caeruleus Acromio-deltoideus. Tohoko J Exper Med. 1954;60:10.
4.Martínez-Peñuela A, Iglesias ME, Mercado MR, Martínez-Peñuela JM. [Malignant transformation of a nevus of Ito: description of a rare case]. Actas Dermosifiliogr. 2011 Dec;102(10):817-20.