Thyroid adenocarcinoma

From Dog
Typical appearance of a dog with a thyroid tumor[1]

Thyroid adenocarcinoma are an uncommon canine thyroid gland tumor, usually affecting older dogs.

A breed predisposition has been noted in the Golden Retriever, Beagle and Siberian Husky[2].

Thyroid adenocarcinoma and thyroid carcinoma represent the majority of thyroid tumors, while thyroid adenomas represented only 10%.

Clinically affected dogs often present with a palpable subcutaneous lump in the ventral cervical region, together with symptoms referable to hyperthyroidism, including panting, polydypsia and polyuria, weight loss, hind limb weakness and weight loss.

Associated with this condition is paraneoplastic hypercalcemia and systemic hypertension[3].

A differential diagnosis would include thyroid adenoma, thyroid carcinoma, thyroid carcinosarcoma, chondrosarcoma[4] and oncocytoma.

Treatment usually requires bilateral thyroidectomy (in resectable cases) and adjunctive therapy including doxorubicin and carboplatin as well as radiation therapy.

In non-resectable cases, particularly where local invasion of structures around the neck are involved[5], debulking and radiation therapy may be warranted as salvage procedures providing up to 1 year of survival[6].

References

  1. Animal Endocrine blogspot
  2. Wucherer KL & Wilke V (2010) Thyroid cancer in dogs: an update based on 638 cases (1995-2005). J Am Anim Hosp Assoc 46(4):249-254
  3. Simpson AC & McCown JL (2009) Systemic hypertension in a dog with a functional thyroid gland adenocarcinoma. J Am Vet Med Assoc 235(12):1474-1479
  4. Rossetto A et al (2011) Mesenchymal chondrosarcoma of the spleen: report of a case. Tumori 97(4):e10-15
  5. Flanders JA (1994) Surgical therapy of the thyroid. Vet Clin North Am Small Anim Pract 24(3):607-621
  6. Carver JR e al (1995) A comparison of medullary thyroid carcinoma and thyroid adenocarcinoma in dogs: a retrospective study of 38 cases. Vet Surg 24(4):315-319