title: Clinical features and treatment outcomes of 41 dogs with sublingual ectopic thyroid neoplasia.
abstract: BACKGROUND
  Thyroid neoplasia is common in dogs, but there are few reports of dogs with ectopic, sublingual thyroid tumors.
  
  
  OBJECTIVE
  To describe clinical features and outcomes of dogs with ectopic, sublingual thyroid neoplasia.
  
  
  METHODS
  Five hundred and forty-four dogs with thyroid neoplasia.
  
  
  METHODS
  This retrospective study reviewed the medical records of dogs referred for thyroid neoplasia between 1995 and 2013. Data extracted included signalment, extent of thyroid disease (eutopic or ectopic; metastasis), serum thyroxine (T4) concentration, treatment, and survival.
  
  
  RESULTS
  Of 544 dogs with thyroid neoplasia, 41 (7.5%) dogs had ectopic sublingual thyroid tumors. The clinical features of these 41 dogs were similar to the cohort group of 503 dogs with eutopic or ectopic mediastinal thyroid tumors, but dogs with sublingual tumors were younger and less likely to have metastatic disease (15% versus 30%, P < .05). Of the 41 dogs, 28 received treatment: 21 with surgery (which included partial hyoidectomy in 13), 7 with radioiodine alone, and 13 with surgery followed by administration of radioiodine. Overall median survival was 562 days (range, 1-1,850 days).
  
  
  CONCLUSIONS
  When compared with eutopic thyroid carcinomas, ectopic sublingual thyroid tumors generally have a less aggressive biologic behavior. Many dogs have prolonged survival, even without treatment, although death because of local tumor invasiveness or metastasis can develop in some dogs. Surgical thyroidectomy, including partial hyoidectomy, is generally effective for control of local disease. Administration of radioiodine, alone or in combination with surgical treatment, is recommended for multifocal disease or metastasis.
authors: Advanced Veterinary Medical Imaging, Tustin, CA.
authors: M R
authors: MR
authors: Broome
authors: M E
authors: ME
authors: Peterson
authors: J R
authors: JR
authors: Walker
mesh_terms: D000818:Animals; D003131:Combined Modality Therapy / Q000662:veterinary; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy; D004285:Dogs; D005260:Female; D008297:Male; D009060:Mouth Floor; D016019:Survival Analysis; D050033:Thyroid Dysgenesis / Q000175:diagnosis / Q000473:pathology / Q000628:therapy / Q000662:veterinary*; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000628:therapy / Q000662:veterinary*; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome
chemical_list: D013974:Thyroxine
keywords: Canine; Hyoidectomy; Hyperthyroidism; Radioactive iodine; Thyroid carcinoma