Poorly Differentiated Thyroid Cancer

Key Clinical Characteristics

  • This is an uncommon form of thyroid cancer, accounting for less than 5% of all cases.
  • This form of thyroid cancer may co-exist with differentiated (papillary or follicular) thyroid cancer.

Basics of Disease Management

  • Poorly Differentiated thyroid cancer may be diagnosed from a fine needle aspiration biopsy of a thyroid nodule.
  • Surgery is the mainstay of treatment for Poorly Differentiated thyroid cancer.
  • Thyroidectomy should be performed by an experienced thyroid surgeon.
  • Endocrinologists play a key role in diagnosing and managing patient’s with thyroid cancer. Most patients will require replacement therapy with thyroid hormone (T4) which requires monitoring.
  • Some patients may benefit from treatment with radioactive iodine. This decision is best made in consultation with an endocrinologist or nuclear medicine specialist.
  • Thyroid cancer treatment should be individualized by a team of specialists to ensure the best possible outcome.
    Poorly differentiated thyroid cancers may or may not produce thyroglobulin that can be measured by a blood test.

Advanced Disease: Special Issues

  • Poorly Differentiated thyroid cancer tends to be more clinically aggressive than differentiated thyroid cancers.
  • Poorly Differentiated thyroid cancer commonly spreads to regional lymph nodes, lungs, and bones.
  • Patients with symptoms due to metastatic thyroid cancer or growth of thyroid cancer in other organs may benefit from consultation with a medical oncologist specializing in thyroid cancer and consideration of targeted therapy or participation in clinical trials.
  • Poorly differentiated thyroid cancers may require treatment with external beam radiation therapy if they have spread to structures outside the thyroid.

Participation in Clinical Trials

  • Clinical trials are carefully controlled experiments that are conducted to discover more effective therapies.
  • Some patients with advanced disease may be candidates for participation in clinical trials.
  • Physicians that specialize in care of patients with advanced thyroid cancer can help identify whether you may be an appropriate candidate for participation in a clinical trial.
  • Consultation with a thyroid cancer specialist to consider new forms of therapy is encouraged for patients with Poorly Differentiated thyroid cancer.


International Thyroid Oncology Group
5166 Commercial Drive
Yorkville, New York 13495