Miscellaneous Thyroid Cancer

Rare Thyroid Cancers

Rare Thyroid Cancers

Very rare, < 1% of all thyroid cancers.

Age at diagnosis typically 70 – 80 years old.
- ~3:1 ratio of women to men.

Usually develops from long-standing Hashimoto’s thyroiditis.

Patients with Hashimoto’s thyroiditis have 70-80 x increased risk of developing PTL.
Cause for this transition is unknown, however it is not thought to be the fault of the patient (i.e. smoking, drinking, diet, exercise etc.).

Commonly presents as a rapidly growing thyroid mass.

Often causing compressive symptoms including pain, difficulty swallowing, voice changes, and/or shortness of breath.
- Can mimic the presentation of Anaplastic Thyroid Cancer (ATC).
  - Needle biopsy should be able to differentiate between ATC and PTL; open biopsy in the operating room if unable to.
- Typically, with a history of long-standing goiter that was previously stable in size.

Difficult to diagnose on biopsy (aka fine needle aspiration).

Hard to distinguish from normal Hashimoto’s thyroiditis.
- Core needle biopsy with flow cytometry can sometimes be performed to help differentiate if the suspicion is high for Lymphoma.
Usually requires an open biopsy performed in the operating room.

PTL is not treated with surgery.

Role for surgery:
- Establish diagnosis with open biopsy.
- Manage acute airway issues (compromised beathing) with tracheotomy if needed or possible.

PTL is treated medically by an oncologist specializing in Lymphoma (typically practicing at an academic university hospital or a high-volume medical center).

Acute compressive symptoms can be managed with high dose corticosteroids.
Combination Radiation to the neck with CHOP chemotherapy provides best outcomes.
- 5-year survival rates approaching 60%.

Very rare, < 1% of all thyroid cancers.

Must rule out metastatic (spread of) Squamous Cell Carcinoma from the mouth or throat.
- Requires detailed exam of the head and neck, CT of the Neck, and possible PET scan.

Cause is unknown; however, it is not thought to be the fault of the patient (i.e. smoking, drinking, diet, exercise etc.).

Typically presents as a rapidly growing thyroid mass.

Often causing compressive symptoms including pain, difficulty swallowing, voice changes, and/or shortness of breath.

Needle biopsy (FNA) is reliable to make a diagnosis.

Given low incidence, consensus treatment guidelines do not exist.

Treated aggressively with surgery (total thyroidectomy if resectable).
- Low threshold for neck dissection of appropriate compartment if lymph node spread is suspected or confirmed on biopsy.
Additional treatment in the form of radiation and chemotherapy is usually recommended.
- To discuss these treatment options, patients should be referred to a Head and Neck Oncologist who specializes in the treatment of advanced thyroid cancers (typically practicing at an academic university hospital).

PSCC is very aggressive with poor prognosis.

Average survival approaches less than 6 months.

This involves cancers starting in an organ somewhere else in the body, then spreading (metastasizing) to the thyroid gland.

The thyroid gland is highly vascular (lots of blood supply), making it a site of potential spread via the blood system.

Very rare, < 1% of all cancers in the thyroid.

Most common primary tumor site is kidney, followed by lung, head and neck, breast, and colon.

Often presents 4-5 years after the diagnosis of the primary cancer.
- For renal cell carcinoma (originating in the kidney), metastasis to the thyroid can be diagnosed ~ 9 years later.
- Rarely is the thyroid the first site of distant metastasis.

Can present as a palpable neck mass, or incidentally on imaging (PET scan, CT of the Neck or Chest) either during work-up of the primary cancer initial diagnosis, or later during surveillance.

Treatment depends on the prognosis of the primary cancer and how many other sites of metastasis are involved.

If isolated to the thyroid and the prognosis is favorable from the primary cancer, surgery is a reasonable option.
- Hemithyroidectomy of the affected thyroid lobe is typically sufficient.
Decision for surgical treatment should be made as part of a multidisciplinary team including the oncologist and surgeon, as well as the patient.

For all types of thyroid cancer, surgical outcomes / cure rates are the highest and complication rates are the lowest when surgery is performed by a high-volume surgeon (> 50 thyroid cancer surgeries per year).

To read more about Thyroid and Neck Dissection surgeries including what to expect, as well as details regarding recovery and risks:

Miscellaneous Thyroid Cancer

Rare Thyroid Cancers