Estudo morfológico das neoplasias melanocíticas uveais em cães

Current Therapeutics and Future Perspectives to Ocular Melanocytic Neoplasms in Dogs and Cats

“…Melanomas are histologically confirmed tumours with malignant characteristics, and melanocytomas are benign tumours with no metastatic potential [ 6 , 7 , 8 ]. Melanomas originate from melanocytes or other neoplastic cells that develop from melanocytes or melanoblasts [ 9 ]. Although benign, melanocytomas have the capacity for local expansion and impairment of adjacent structures [ 5 , 10 ].…”

“…Melanocytic neoplasms clinical presentation is non-specific and varies according to the eventual destruction or disarrangement of ocular structures [ 12 ]. Unilateral involvement is the most frequent [ 9 ]. Clinical signs include visual loss, corneal opacity, hyphema, endophthalmitis, uveitis, retinal detachment, presence of expansive/invasive neoformations [ 12 , 13 ] (see Figure 1 A,B), alterations of pigmentation (see Figure 1 C) and secondary glaucoma (common; see Figure 1 D) [ 14 ].…”

“…Melanocytic neoplasms tend to occur in adult to elderly animals [ 13 , 23 ], but there are cases in young animals [ 24 ]. Gender [ 13 , 25 ] or breed predisposition is yet to be confirmed [ 7 , 20 , 23 , 26 , 27 , 28 ], since the apparent higher prevalence in some breeds may be related to their popularity and not predisposition [ 9 ].…”

“…The aetiology of ocular melanoma is not fully elucidated [ 9 ], but some factors may be related, such as genetic [ 29 ], pigmented region lesions [ 2 , 15 , 30 ], exposure to UV radiation [ 31 ] and possible viral infection [ 32 ]. Experimental studies showed uveal melanomas could be induced in dogs with the intravenous administration of radioactive material [ 33 ].…”

“…In dogs, the melanocytic neoplasms reported in the conjunctiva [ 10 , 39 ] and the orbit [ 2 , 20 ] are predominantly malignant, while those originating in the eyelid (see Figure 1 D), the limbus and the uvea are predominantly benign [ 1 , 2 , 5 , 6 , 20 , 29 , 40 ]. Melanomas with areas of melanocytoma were also observed, suggesting malignant transformation [ 9 ]. Cats are often diagnosed with intraocular melanocytic neoplasms, which diffuse in the iris [ 41 ] and gradually become a coalescing infiltrative lesion [ 14 ].…”