Neoplasmas da tireoide em cães: 26 casos / Thyroid neoplasms in dogs: 26 cases

RESUMO

Foram revisados os protocolos de biópsias e necropsias do Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV/UFSM) entre 2004 e 2014, e todos os casos de tumores que acometeram a glândula tireoide foram selecionados. A partir disso, foram anotados sexo, idade e raça dos cães afetados. Também foi avaliado o significado clínico dos tumores, presença de aumento de volume cervical, lobos afetados, tamanho dos tumores, presença e localização de metástases e padrão histológico dos neoplasmas. Nos 11 anos que compreenderam este estudo, foram diagnosticados 26 tumores de glândula tireoide (quatro eram provenientes de exames de biópsias e 22 de necropsias), 53,9% dos cães eram fêmeas e 46,1% eram machos; 65,4% eram cães com raça definida. Desses, Boxers foram os mais afetados (15,4% dos casos). Dos 23 protocolos em que a idade foi informada, 60,9% dos cães eram idosos e 39,1% eram adultos. A avaliação dos protocolos permitiu constatar que 38,5% dos animais haviam apresentado aumento de volume cervical no momento do exame clínico. Dos cães necropsiados 13,6% morreram ou foram submetidos à eutanásia em decorrência de complicações causadas por metástases dos tumores de tireoide. Dessa forma, em 86,4% dos cães, os neoplasmas foram considerados achados incidentais de necropsia. Nos quatro casos provenientes de material de biópsia, o desfecho não foi conhecido. Em nenhum cão os tumores causaram síndrome clínica devido à hipo ou hiperfunção da tireoide. Em 24 protocolos havia informação sobre os lobos afetados e 75% dos cães tiveram acometimento unilateral da glândula. Os diagnósticos histológicos dos tumores permitiram constatar que 16 (61,5%) neoplasmas eram carcinomas de células foliculares (nesses casos, o padrão folicular-compacto foi o mais frequente [43,75%]), seis (23,1%) eram adenomas de células foliculares, dois (7,7%) eram carcinossarcomas e dois (7,7%) eram tumores de células C (adenoma e carcinoma).(AU)

ABSTRACT

Biopsy and necropsy reports of the Laboratório de Patologia Veterinária at the Universidade Federal de Santa Maria (LPV/UFSM) were reviewed, including data from 2004 to 2014; all cases of the thyroid tumors were selected. From this point on, it was recorded the gender, age and breed of affected dogs. Additionally, it was evaluated the clinical significance of these tumors, presence of cervical swelling, affected lobes, tumors size, presence and location of metastasis and histological pattern of neoplasms. Twenty six thyroid tumors were diagnosed in the study period (four came from biopsies while the other 22 were from necropsies). Of the affected dogs, 53.8% were females and 46.2% were males; most of the animals (65.4%) were purebred. Of these, Boxers were the most affected (15.4%). In 23 protocols the age was informed; 60.9% of the dogs were elderly and 39.1% were adults. The protocols evaluation allowed establishing that 38.5% of the animals had cervical swelling, at the time of clinical examination. Out of the dogs necropsied, only 13.6% died or were euthanized due to complications caused by metastases of thyroid tumors. Thus, in 86.4% of the dogs, the neoplasms were considered as incidental necropsy findings. In the four cases from biopsy samples, the outcomes were not known. There were no tumors causing clinical syndrome in these dogs, due to thyroid hypo- or hyperfunction. In 24 protocols it was found information about the affected lobes, indicating that 75% of the dogs had unilateral glandular involvement. The histological diagnosis showed that 16 (61.5%) neoplasms were follicular cell carcinomas (in these cases, the follicular-compact pattern was the most frequent [43.8%]); 6 (23.1%) were follicular cells adenoma; two (7.7%) were carcinosarcomas and two (7.7%) were C cells tumors (adenoma and carcinoma).(AU)