What work ups are needed, if any?

MALIGNANT VS. BENIGN

• History taking• Physical examination• Fine-needle aspiration

biopsy (FNAB)• Other imaging and

laboratory evaluation

Evaluation of a Thyroid Nodule• History

– Risk factors for thyroid cancer• History of thyroid irradiation, especially in infancy or childhood• Age < 20 yr• Male sex• Family history of thyroid cancer or multiple endocrine neoplasia• A solitary nodule• Dysphagia• Dysphonia• Increasing size (particularly rapid growth or growth while receiving thyroid

suppression treatment)• Physical Examination

– Signs that suggest thyroid cancer• stony hard consistency or fixation to surrounding structures• cervical lymphadenopathy• hoarseness due to recurrent laryngeal nerve paralysis

Testing

• Fine-Needle Aspiration Biopsy (FNAB)– Cornerstone in the evaluation of solitary thyroid

nodules and also dominant nodules within multinodular goiters

– Currently considered to be the best first-line diagnostic procedure in the evaluation of the thyroid nodule

Fine-Needle Aspiration Biopsy

• Advantages:– Safe– Cost-effective– Minimally invasive– Leads to better selection of patients for surgery

than any other test (Rojeski, 1985)– Halved the number of patients requiring

thyroidectomy (Mazzaferri, 1993)– Double the yield of cancer in those who do

undergo thyroidectomy (Mazzaferri, 1993)

Fine-Needle Aspiration Biopsy• Limitations

– Skill of the aspirator– Expertise of the cytologist– Difficulty in distinguishing some benign cellular adenomas from

their malignant counterparts (follicular and Hurthle cell)

• Sensitivity: 65 – 98% (avg. 83%)• Specificity: 72 – 100% (avg. 92%)• Positive Predictive Value: 50 – 96% (avg. 75%)• False-negative Rates: 1.5 – 11.5% (avg. < 5%)• False-positive Rates: 0 – 8% (avg. 3%)

Reference: Gharib, H. (2008). Fine-Needle Aspiration Biopsy of the Thyroid Gland. Thyroid Disease Manager.

Fine-Needle Aspiration Biopsy

• Four Categories of Cytologic Diagnosis– Benign (Negative) – 69%– Suspicious (Indeterminate) – 10%– Malignant (Positive) – 4%– Unsatisfactory (Nondiagnostic) – 17%

Reference: Gharib, H. (2008). Fine-Needle Aspiration Biopsy of the Thyroid Gland. Thyroid Disease Manager.

CT/MRI

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

Staging and Prognosis• AGES and AMES scoring systems

– A Age of patient– G Tumour Grade– M Distant metastasis– E Extent of tumour– S Size of tumour

• Both scoring systems have identified 2 distinct subgroups; – Low-risk group; Men 40years or younger, women 50 or younger, without

distant metastasis (bone & lungs)– Older patients with intrathyroid follicullar/papillary carcinoma, with

minor capsular involvement with tumours < 5cms in diameter– High –risk group; All patients with distant metastasis– All older patients with extrathyroid papillary/follicular carcinoma &

tumours >5 cms regardless of extent of disease

MAICS

AMES

Treatment Options

Surgical Treatment: Papillary CA

High risk or bilateral tumors: Total or near - total thyroidectomy

Minimal Papillary Thyroid TumorUnilateral lobectomy and isthmusectomy

•Enables the use of RAI for detecting and treating residual thyroid tissue and metastatic disease. •Makes serum Tg level a more sensitive marker of recurrent or persistent disease•Eliminates contralateral occult cancer as sites of recurrence•Reduces risk of recurrence•Increases survival•Decreases 1% risk of progression to ATC•Reduces need for reoperative surgery

Total Thyroidectomy

•Lower complication rate•Recurrence is unusual (5%)•Excellent prognosis

Unilateral Lobectomy

Why Thyroidectomy?

• Recurrence rates are lowered and survival is improved when a patient underwent thyroidectomy

• Diminished survival was noted in patients with low-risk disease

Total Thyroidectomy

• Enables the use of RAI for detecting and treating residual thyroid tissue and metastatic disease.

• Makes serum Tg level a more sensitive marker of recurrent or persistent disease

• Eliminates contralateral occult cancer as sites of recurrence

• Reduces risk of recurrence• Increases survival• Decreases 1% risk of progression to ATC• Reduces need for reoperative surgery

1) 30%-87.5% of papillary carcinomas involve opposite lobe (Hirabayashi, 1961, Russell, 1983)

2) 7%-10% develop recurrence in the contralateral lobe (Soh, 1996)

3) Lower recurrence rates, some studies show increased survival (Mazzaferri, 1991)

4) Facilitates earlier detection and tx for recurrent or metastatic carcinoma with RAI (Soh, 1996)

5) Residual WDTC has the potential to dedifferentiate to ATC

Rationale for total thyroidectomy

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

Rationale for subtotal thyroidectomy

1) Lower incidence of complications Hypoparathyroidism (1%-29%) (Schroder, 1993) Recurrent laryngeal nerve injury (1%-2%) (Schroder,

1993) Superior laryngeal nerve injury

2) Long term prognosis is not improved by total thyroidectomy (Grant, 1988)

Non- Surgical approach

• External Beam Radiotherapy and Chemotherapy

• Radioiodine Therapy

• TSH Suppresion Therapy