Nevus of Ota: Extracutaneous Involvement and Variants
The first case of phakomatosis pigmentovascularis (Figure 6) was described in 1920 in a patient with generalized hemangioma and nevus pigmentosus verrucosus, but it was not until 1947 that Ota reported the association of congenital generalized hemangioma with nevus of Ota. Hasegawa and Yasuhara have since classified phakomatosis pigmentovascularis into four subtypes that are further subgrouped according to the presence or absence of systemic involvement. Among Hasegawa and Yasuhara's patients, 85% were type II, 10% were type IV, and 5% were type III. Similar to nevus of Ota, phakomatosis pigmentovascularis has been reported to be more common in women than men. Systemic involvement is not unusual, and includes ocular and neurologic disorders such as Sturge-Webber disorder, Klippel-Trenaunay syndrome, or intracranial arteriovenous malformation. Indeed, in view of the link to neurologic disease, in 1947 Ota et al. proposed the name phakomatosis pigmentovascularis.
Ocular pigmentation is common in nevus of Ota, and affects from 22%-77% of patients with pigmentation affecting the sclera, iris, and conjunctiva (Figure 7).[7,22] It is not uncommon for patients with nevus of Ota to have ocular complications. One study examined 194 patients with oculodermal melanocytosis and specifically looked for evidence of ocular involvement. The findings indicate that dermal hyperpigmentation in the combined distribution of the ophthalmic and maxillary divisions of the trigeminal nerve and hyperpigmentation of the nasal or buccal mucosa are particularly linked to the development of ocular disease. Among the ocular complications, increased intraocular pressure with or without glaucoma was the most common (10.3%), followed by asymmetric cupping of the optic nerve head that was not associated with glaucoma (9.8%), uveitis (2.6%), cataracts (1%), and, rarely, orbital melanoma (0.5%). Other less common ocular diseases, such as retinitis pigmentosa, have been reported, but such presentations are likely to be coincidental findings rather than true associations.
Orbital and cerebral melanomas have rarely been associated with nevus of Ota, but are considered to be the most lethal complications. In most of the reported cases, patients are Caucasian, but other groups have been reported including blacks, Hispanics, Thais, Indians, and Malays.[22,24,25,26,27,28,29] Interestingly, a recent MEDLINE search failed to identify any reported case of melanoma that arose from nevus of Ota among Japanese and Chinese.
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Cite this: Nevus of Ota: Clinical Aspects and Management - Medscape - Mar 01, 2003.