The Study of Cutaneous Melanomas in Camargue‐Type Gray‐Skinned Horses (2): Epidemiological Survey

Abstract

An epidemiological survey was made on cutaneous melanomas occurring in Camargue-type, gray-skinned horses in southern France. The population investigated was composed of 264 horses, which were selected from the Camargue horse stud registry and were allowed to be examined by the owners. The presence of tumors was inspected macroscopically according to the standardized protocols of veterinary medicine specialists, and some tumors were subjected to macroscopic histopathological examination. The results indicated that: 1) the prevalence of melanomas in the overall population was 31.4%; 2) the odds ratio was obtained for an age class of 5-9 years, in which most melanomas were presumed to occur; 3) the incidence of melanomas was significantly correlated with age, giving a prevalence of 67% at ages > 15 years; 4) the size and number of tumorous lesions were significantly related to age; 5) little correlation was observed between melanoma incidence and gender; and 6) the most frequently occurring body site of these tumors was underneath the tail. Because of their frequent occurrence in shaded body regions, sun exposure was not likely to be a risk factor for melanoma formation in these horses. In view of the slightly darker skin pigmentation in these horses at younger ages, the unique characteristics of their melanocytes may be associated with melanoma formation.

Ocorrência de melanoma em equinos abatidos em matadouro frigorífico exportador de Minas Gerais

“…1268, 2012 A maioria dos tumores melanocíticos inicia-se na região ventral da cauda, no períneo e na genitália externa e, menos comumente, na glândula parótida, na orelha, na pálpebra, nos membros e no pescoço. Após transformação maligna, a formação de metástases ocorre via hematogênica, linfática ou por implantação, e os principais locais envolvidos são linfonodos regionais, baço, fígado, pulmões, vasos sanguíneos e coração (FLEURY et al, 2000;JOHNSON, 1998;MACGILLIVRAY;SWEENEY;PIERO, 2002).…”

Melanoma maligno anaplásico em um eqüino

“…O neoplasma aqui relatado foi classificado como melanoma maligno anaplásico (VALENTINE, 1995). Estudos indicam que a maioria dos neoplasmas melanocíticos inicia-se na região ventral da cauda, no períneo e na genitália externa e, menos comumente, na glândula parótida, na orelha, na pálpebra, nos membros e no pescoço (FLEURY et al, 2000;MACGILLIVRAY et al, 2002). Após transformação maligna, a formação de metástases ocorre via hematogênica, linfática ou por implantação, e os principais locais envolvidos são linfonodos regionais, baço, fígado, pulmões, vasos sanguíneos e coração (JOHNSON, 1998;MACGILLIVRAY et al, 2002).…”

Estimation of genetic parameters for melanoma in the Old Kladruber horse

“…Sundberg et al (1977) reported higher frequencies of melanoma occurrence in males. Fleury et al (2000b) recorded a higher melanoma occurrence in geldings compared to mares and stallions but the differences were on the boundary of statistical significance. The other authors are also convinced that sex does not influence the occurrence of melanoma (e.g.…”