Nevus of Ota

Kissing Nevus With Ocular Melanosis: A Case Report in Hail Region, Saudi Arabia.

“…Mostly it is a benign unilateral melanocytosis, also 80% of the patients were females [5] and 48% of patients developed a nevus of Ota at or after birth compared to 11% between 1 and 10 years of age and 36% at puberty [6].…”

Plaque-Type Blue Nevus of the Oral Cavity

“…The brown spots correspond histologically to an epidermal hyperpigmentation. Rarely there may be a slightly raised papular or nodular component [18]. About 11% are bilateral [19].…”

“…The sclera, conjunctiva, cornea, iris, retina, optic nerve, extraocular muscles, retrobulbar fat, the pharynx, the nasal mucosa and the tympanic membrane may be involved. Involvement of the mucosa of the oral cavity is not an uncommon feature in Japanese subjects but can be found only very rarely in non-Orientals [9, 18]. Any area of the oral cavity can be affected, although most lesions are observed on the palatal mucosa.…”

Don’t it make my blue eyes brown: heterochromia and other abnormalities of the iris

“…74 Indeed, it has been suggested that Naevus of Ota arises as a result of an arrest in the migration of neural crest melanocytes, which leads to the aggregation of these cells in the dermis. 78 While this hypothesis provides a plausible explanation for the presence of melanocytes within the affected dermis, it does not explain the excessive numbers of melanocytes found within the ocular tissues. Other explanations include local changes in the embryonic environment, which leads to the preferential differentiation of migrating neural crest cells into a melanocytic phenotype.…”

“…Occasionally, there may be pigmentation of the eardrum, buccal mucosa, palate, nasopharynx, and leptomeninges. 78,93 A number of ocular tissues may be involved, including the conjunctiva, episclera, cornea, iris, lens, anterior chamber angle, choroid, and optic disc. 73 The episclera is almost always involved and may range from relatively discreet bluish spots to confluent dark mottled patches, which are dispersed randomly on the globe, but usually do not involve the limbus.…”