MELANOMA COMPLICATING A NEVUS OF OTA WITH OUT OCULAR MELANOSIS - A PATHOLOGY-CLINICAL CASE

The naevus of Ota is a congenital pigmentary disorder usually involvin g the skin of the face in areas supplied by the first and second branc hes of the trigeminal nerve. Ipsilateral ocular melanosis is associate d in 2/3 of the cases. The naevus occurrs most often in Asians. There have been 66 reported cases of malignant transformation of the naevus of Ota, generally affecting caucasians: 23 were melanomas of the eyeba ll (mostly of the choroid), and 13 were orbital melanomas. Only 4 case s of melanomas associated with a naevus of Ota without ocular melanosi s have been previously described. We report a new case of orbital mela noma affecting a 30-year-old man. This melanoma complicated a right ty pe III of Tanino naevus of Ota without ocular melanosis. The location of the tumor to the orbital apex and its extension to the spheno-caver nous area was responsible for an ipsilateral loss of vision without pr optosis, which has not yet been described in any case of naevus of Ota without ocular melanosis.