Subtype of compact follicular thyroid carcinoma in a canine

Abstract

Thyroid tumors represent 4% of neoplasms in dogs, being the most common carcinomas, corresponding to 88% of thyroid tumors. These are characterized by their rapid growth and invasiveness. Due to this, the present study aims to report a case of compact follicular subtype thyroid carcinoma in a canine, with emphasis on its clinical, diagnostic and therapeutic aspects. A seven-year-old male, neutered, mixed-breed canine, weighing 27 kg, complained of dyspnea for 60 days, weight loss, dysphonia and increased volume in the topography of the thyroid gland was treated. Ultrasound-guided fine-needle cytology was performed with a diagnosis suggestive of thyroid carcinoma. Afterwards, computed tomography was requested for surgical planning. As treatment, we chose to use toceranib phosphate, 3.25 mg.kg-1, three times a week, associated with piroxicam 0.3 mg.kg-1, once a day, for 60 days, in which he presented reduction in the size of the mass and clinical signs, so the patient underwent surgical resection and a tissue fragment was sent for histopathological analysis, which confirmed the diagnosis of compact follicular subtype carcinoma. Postoperatively, the patient's clinical condition worsened and, despite intensive management, died. Thyroid neoplasms have aggressive biological behavior and low survival, and adjuvant therapy with toceranib phosphate it was efficient in reducing the neoplastic mass. Still, the cytological examination is a crucial screening tool for diagnostic conduction, however, the definitive diagnosis can only be performed by histopathological analysis.