THYROID CA

D3Tambal – Tolentino

Salient Features

39 year old female, No exophthalmos, 25x20cm multinodular anterolateral neck mass which moves with deglutition with a 5x3cm hard nodule, palpable cervical adenopathies, no fever, no weight loss, no tremors, no easy fatigability, no abdominal pain

Thyroid CancerClinical Impression

Differential Diagnosis

The Most Common Thyroid Cancer arises as an irregular, solid or cystic mass that

arises from otherwise normal thyroid tissue Cervical metastasis (spread to lymph nodes in

the neck) are present in 50% of small tumors and in over 75% of the larger thyroid cancers

Distant metastasis (spread) is uncommon, but lung and bone are the most common sites

Papillary Cancer

Characteristics of Papillary Thyroid Cancer

• Peak onset ages 30 through 50• Females more common than males by 3 to 1 ratio• Prognosis directly related to tumor size [less than 1.5 cm

(1/2 inch) good prognosis]• Accounts for 85% of thyroid cancers due to radiation exposure• Spread to lymph nodes of the neck present in more than 50%

of cases• Distant spread (to lungs or bones) is very uncommon• Overall cure rate very

Follicular Cancer

• The Second Most Common Type of Thyroid Cancer• considered more malignant (aggressive) than papillary

carcinoma• It occurs in a slightly older age group than papillary and

is also less common in children• Mortality is related to the degree of vascular invasion• Vascular invasion is characteristic for follicular

carcinoma and therefore distant metastasis is more common

• Lung, bone, brain, liver, bladder, and skin are potential sites of distant spread

• Lymph node involvement is far less common than in papillary carcinoma.

Differential Diagnosis

Characteristics of Follicular Thyroid Cancer

• Peak onset ages 40 through 60• Females more common than males by 3 to 1 ratio• Prognosis directly related to tumor size [less than 1.0

cm (3/8 inch) good prognosis]

• Rarely associated with radiation exposure• Spread to lymph nodes is uncommon (~10%)• Invasion into vascular structures (veins and arteries)

within the thyroid gland is common• Distant spread (to lungs or bones) is uncommon, but

more common than with papillary cancer• Overall cure rate high (near 95% for small lesions in

young patients), decreases with advanced age

Medullary Cancer

The Third Most Common Thyroid Cancer originates from the parafollicular cells (also called

C cells) of the thyroid This cancer has a much lower cure rate than

does the "well differentiated" thyroid cancers (papillary and follicular)

Overall 10 year survival rates are 90% when all the disease is confined to the thyroid gland, 70% with spread to cervical lymph nodes, and 20 when spread to distant sites is present.

Differential Diagnosis

Characteristics of Medullary Thyroid Cancer

• Occurs in 4 clinical settings: Sporadic, MEN II-A, MEN II-B, Inherited medullary carcinoma without associated endocrinopathies

• Females more common than males (except for inherited cancers)

• Regional metastases (spread to neck lymph nodes) occurs early in the disease

• Spread to distant organs (metastasis) occurs late and can be to the liver, bone, brain, and adrenal medulla

• Not associated with radiation exposure• Usually originates in the upper central lobe of the thyroid• Poor prognostic factors include age >50, male, distant spread

(metastases), and when seen in patients with other endocrine tumors due to MEN II-B syndrome.

• Residual disease (following surgery) or recurrence can be detected by measuring calcitonin (a hormone that should be measured every 4 months for the first few years and then every 6 months for ever)

Anaplastic Cancer

• The Least Common Thyroid Cancer• Anaplastic tumors are the least common and most

deadly of all thyroid cancers • Only 10% of patients are alive 3 years after it is

diagnosed. Most patients with anaplastic thyroid cancer do not live one year from the day they are diagnosed.

• Anaplastic thyroid cancer often arises within a more differentiated thyroid cancer or even within a goiter.

• Cervical metastasis (the spread of the cancer to lymph nodes in the neck) are present in the vast majority (over 90%) of cases at the time of diagnosis. The presence of lymph node metastasis in these cervical areas causes a higher recurrence rate and is predictive of a high mortality rate.

Differential Diagnosis

Characteristics of Anaplastic Thyroid Cancer

• Peak onset age is 65 and older.• It's very rare in young patients.• It's more common in males than females by 2 to 1 ratio.• It typically presents as rapidly growing neck mass.• It can occur many years after radiation exposure.• The spread to lymph nodes of the neck is present in more

than 90% of cases.• The distant spread (to lungs or bones) is very common even

when it's first diagnosed.• The overall cure rate is very low.• It typically requires a very aggressive treatment plan with

surgery, radiation, and sometimes even chemotherapy.• It often requires a tracheostomy to maintain the patient's

airway.

Clinical Diagnosis

Papillary Cancer

What work ups are needed, if any?

MALIGNANT VS. BENIGN

History taking Physical

examination Laboratory evaluat

ion Fine-needle aspirat

ion biopsy (FNAB)

FINE NEEDLE ASPIRATION BIOPSY Most important

diagnostic tool in evaluating thyroid nodules and should be the first intervention

Inexpensive, easy to perform, causes few complications

Successful diagnosis by the cytologist depends on accurate sampling of the nodule and specimen cellularity

At least 3 aspirations Ensure adequacy of

specimen Minimize false

negative results

THYROID STIMULATING HORMONE (TSH)

A sensitive TSH assay is useful in the evaluation of solitary thyroid nodules

Benign = low serum TSH

Malignant = cannot be determined

SERUM THYROGLOBULIN

Not helpful diagnostically Elevated in most benign thyroid

conditions

Other thyroid function tests are usually not necessary in the initial workup

SERUM CALCITONIN

• Elevated levels are highly suggestive of medullary thyroid carcinoma (MTC)

• Once the mainstay in the diagnosis of FMTC

• Replaced by sensitive polymerase chain reaction (PCR) assays for germline mutations in the RET proto-oncogene

• Currently used as tumor markers to monitor patients who have been treated for MTC

Treatment Options

Surgical Treatment

thyroid lobectomy, isthmusectomy, and removal of any pyramidal lobe or adjacent lymph node

total or near-total thyroidectomy

Non- Surgical approach

External Beam Radiotherapy and Chemotherapy

Radioiodine Therapy

TSH Suppresion Therapy

How would you manage the patient? Immediate postop? In the next 4 to 6 weeks? Long term plans?

Total Thyroidectomy vs. Less than Total Thyroidectomy

Surgical Treatment

INDICATIONS for TOTAL THYROIDECTOMY

1) Patients older than 40 years with papillary or follicular carcinoma

2) Anyone with a thyroid nodule with a history of irradiation

3) Patients with bilateral disease

Postoperative therapy

Radioiodine Therapy- 75% of patients with metastatic differentiated thyroid CA can be detected and treated by 131I

External Beam Radiotherapy and Chemotherapy- required occasionally to control unresectable locally

invasive or recurrent disease -treatment and control of pain from bony

metastases when there is no appreciable radioiodine uptake.

Thyroid Hormone – suppress and reduce the growth stimulus for any possible residual thyroid cancer cells

-Low-risk patients: TSH levels of 0.1µU/L-High-risk patients: <0.1µU/L

Follow-Up

Radioactive iodine-Scan at 4-6 weeks postoperatively-repeat scan at 6-12 months after ablation-repeat scan at 1 year-and every 2 years thereafter

Thyroglobulin Measurement

-Initially at 6-month intervals

- annually if the patient is clinically disease free - >2 ng/mL ; suggestive of metastatic disease or

persistent normal thyroid tissue

Imaging -6 to 12 months after remnant ablation with high

orintermediate risk

- 6 and 12 months; cervical US to evaluate the thyroid bed and central and lateral cervical nodal compartments;

- Annually for at least 3 to 5 years, depending on the patients’ risk

Acute Long term

Neck pain, swelling, and tenderness Hematologic Bone marrow suppression (>500 mCi) Leukemia (>1000 mCi)

Thyroiditis (if remnant present) Fertility Ovarian/testicular damage, infertility Increased spontaneous abortion rate

Sialadenitis (50–450 mCi), taste dysfunction

Pulmonary fibrosis

Hemorrhage (brain metastases) Chronic sialadenitis, nodules, taste dysfunction

Cerebral edema (brain metastases, 200 mCi)

Increased risk of cancer: Anaplastic thyroid cancer,  Gastric cancer, Hepatocellular cancer, Lung cancer, Breast cancer (>1000 mCi), Bladder cancer

Nausea and vomiting (50–450 mCi) Hypothyroidism

Bone marrow suppression (200 mCi)

Complications of Radioactive Iodine Therapy (131I) and Doses at Which They Are Observed