Rare primary choroidal melanoma in a dog, with optic nerve infiltration

Abstract

Intraocular melanocytic neoplasms are common in dogs. However, the choroidal location of these neoplasms and their infiltration into the optic nerve are unusual. This paper reports a case of primary choroidal melanoma in a 12-year-old male Dachshund. On the first examination, the animal presented left eye blepharospasm, protrusion of the nictitating membrane, conjunctival hyperemia, moderate congestion, hyphema, and intraocular hypertension. Opacity hindered the performance of fundoscopy in the affected eye. The ocular ultrasound examination revealed a cupuliform mass in the choroid. Due to suspected intraocular neoplasia, an exenteration was performed. Histopathological examination revealed primary choroidal melanoma with scleral and optic nerve invasion.

Unilateral invasive intraocular melanoma with choroidal and optic nerve involvement resulting in bilateral vision loss in a Labrador Retriever

“…The mass in this case infiltrated the posterior choroid and optic nerve and traveled caudally to the level of the optic chiasm and contralateral optic nerve. Invasion of choroidal melanocytomas/melanomas into the optic nerve has been reported in both dogs and in humans 6–12 . As there are no reported cases of primary optic nerve melanomas in dogs, a choroidal origin with extraocular extension was considered most likely in this case, however, an optic nerve origin cannot be ruled out.…”

“…Invasion of choroidal melanocytomas/ melanomas into the optic nerve has been reported in both dogs and in humans. [6][7][8][9][10][11][12] As there are no reported cases of primary optic nerve melanomas in dogs, a choroidal origin with extraocular extension was considered most likely in this case, however, an optic nerve origin cannot be ruled out. There are reports of tumors arising from both locations in physician literature.…”