Thyroid adenoma

From Dog

Thyroid adenomas are a benign neoplasm of the canine thyroid gland.

These tumors are rare and usually discovered at necropsy.

Some thyroid adenomas are hormonally active and dogs may present with signs referable to hyperthyroidism, including progressive weight loss, tachycardia, hyperthermia, polyuria and polydipsia.

A freely movable mass may be palpable in the cranioventral cervical region.

Diagnosis is based on fine-needle biopsy and histological analysis, showing neuroendocrine tissue with low levels of pleomorphic change and lack of vascular or stromal invasion.

A differential diagnosis would include thyroid carcinoma and mast cell tumor.

Treatment usually requires surgical excision and is usually curative[1].


  1. Itoh T et al (2007) Functional thyroid gland adenoma in a dog treated with surgical excision alone. J Vet Med Sci 69(1):61-63