Spindle B cell melanoma in the choroid of a dog


  • *The Central Veterinary Laboratory, New Haw, Weybridge, Surrey, KT15 3NB.


An 8-year-old Schnauzer bitch developed a placoid pigmented mass in the dorso-nasal quadrant of the fundus. A malignant melanoma was diagnosed on the basis of its ophthalmoscopic appearance and on its A and B scan ultrasonography features. Histopathology revealed that the mass was a heavily pigmented spindle B cell melanoma of the choroid. Bruch's membrane was ruptured and the retina was locally detached. The tumour had features similar to choroid melanomas in man which arise from nevi. A review of the literature and of 16 previously unpublished cases of primary canine uveal melanomas confirmed the prevailing impression that choroidal melanomas are rare in the dog.