Nevus of Ota – an intraoral presentation: a case report

BACKGROUND: Nevus of Ota or “oculodermal melanocytosis” is a rare congenital hamartoma of dermal melanocytes causing a blue-gray hyperpigmentation of the eye and surrounding structures. The condition, originally described by Ota and Tanino in 1939, mainly affects the ophthalmic and maxillary divisions of the trigeminal nerve. We describe the first reported case of unilateral oculodermal melanocytosis in a Caucasian woman with oral buccal mucosal involvement. Oral involvement of nevus of Ota is very rare. CASE PRESENTATION: A 48-year-old Caucasian woman was referred by the dermatology division to the oral medicine department at the University of Liverpool School of Dentistry with new-onset oral pigmentation to the left buccal mucosa. The patient had a previous diagnosis of oculodermal nevus. CONCLUSION: An incisional biopsy of the left buccal mucosa was completed. The report stated that histological and immunohistochemical features were in keeping with a blue nevus, but within the context of the preexisting occulodermal pigmentation, a diagnosis of oculodermal melanocytosis, also known as “nevus of Ota,” was made. The patient will be kept under review in the oral medicine department because the progression of the lesion on the left buccal mucosa requires active monitoring owing to the potential for malignant change. The patient also requires regular review in the dermatology and ophthalmology divisions.