Primary hypothyroidism due to thyroid carcinoma in a feline

ABSTRACT: Hypothyroidism is rarely observed in cats. This article reports the case of a thirteen-year-old feline with a one-year history of bilateral cervical swelling that had majorly grown in size two weeks prior to the animal’s admission. The cat presented with dysphonia, lethargy, weight gain, and constipation. On physical examination, hypothermia was observed, with a rectal temperature of 36.5 ºC. Fine-needle aspiration cytology suggested thyroid neoplasia. The serum levels of total T4 and thyroid stimulating hormone (TSH), along with the exclusion of non-thyroid diseases, confirmed the diagnosis of hypothyroidism. This is the first report of feline hypothyroidism in Brazil secondary to thyroid neoplasia, classified as a follicular-compact carcinoma and confirmed by histopathology.

摘要：猫甲状腺功能减退症（Hypothyroidism）临床罕见。本文报告1例13岁家猫病例，该猫存在1年的双侧颈部肿胀病史，且在入院前2周肿胀体积显著增大。该猫表现为声音嘶哑、精神沉郁、体重增加及便秘。体格检查发现体温过低，直肠体温为36.5℃。细针抽吸细胞学检查（fine-needle aspiration cytology）提示甲状腺肿瘤（thyroid neoplasia）。结合血清总甲状腺素（total T4）与促甲状腺激素（thyroid stimulating hormone, TSH）水平检测结果，并排除非甲状腺疾病后，确诊该猫为甲状腺功能减退症。本研究为巴西首例由甲状腺肿瘤继发的猫甲状腺功能减退症病例，该肿瘤经组织病理学（histopathology）确诊为滤泡致密型癌（follicular-compact carcinoma）。