4Salient Features39 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
6Differential Diagnosis Papillary CancerThe Most Common Thyroid Cancerarises as an irregular, solid or cystic mass that arises from otherwise normal thyroid tissueCervical metastasis (spread to lymph nodes in the neck) are present in 50% of small tumors and in over 75% of the larger thyroid cancersDistant metastasis (spread) is uncommon, but lung and bone are the most common sites
7Characteristics of Papillary Thyroid Cancer Peak onset ages 30 through 50Females more common than males by 3 to 1 ratioPrognosis directly related to tumor size [less than 1.5 cm(1/2 inch) good prognosis]Accounts for 85% of thyroid cancers due to radiation exposureSpread to lymph nodes of the neck present in more than 50% of casesDistant spread (to lungs or bones) is very uncommonOverall cure rate very
8Differential Diagnosis Follicular CancerThe Second Most Common Type of Thyroid Cancerconsidered more malignant (aggressive) than papillary carcinomaIt occurs in a slightly older age group than papillary and is also less common in childrenMortality is related to the degree of vascular invasionVascular invasion is characteristic for follicular carcinoma and therefore distant metastasis is more commonLung, bone, brain, liver, bladder, and skin are potential sites of distant spreadLymph node involvement is far less common than in papillary carcinoma.
9Characteristics of Follicular Thyroid Cancer Peak onset ages 40 through 60Females more common than males by 3 to 1 ratioPrognosis directly related to tumor size [less than 1.0 cm(3/8 inch) good prognosis]Rarely associated with radiation exposureSpread to lymph nodes is uncommon (~10%)Invasion into vascular structures (veins and arteries) within the thyroid gland is commonDistant spread (to lungs or bones) is uncommon, but more common than with papillary cancerOverall cure rate high (near 95% for small lesions in young patients), decreases with advanced age
10Differential Diagnosis Medullary CancerThe Third Most Common Thyroid Canceroriginates from the parafollicular cells (also called C cells) of the thyroidThis 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.
11Characteristics of Medullary Thyroid Cancer Occurs in 4 clinical settings: Sporadic, MEN II-A, MEN II-B, Inherited medullary carcinoma without associated endocrinopathiesFemales more common than males (except for inherited cancers)Regional metastases (spread to neck lymph nodes) occurs early in the diseaseSpread to distant organs (metastasis) occurs late and can be to the liver, bone, brain, and adrenal medullaNot associated with radiation exposureUsually originates in the upper central lobe of the thyroidPoor 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)
12Differential Diagnosis Anaplastic CancerThe Least Common Thyroid CancerAnaplastic tumors are the least common and most deadly of all thyroid cancersOnly 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.
13Characteristics 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.
19Successful diagnosis by the cytologist depends on accurate sampling of the nodule and specimen cellularityAt least 3 aspirationsEnsure adequacy of specimenMinimize false negative results
20THYROID STIMULATING HORMONE (TSH) A sensitive TSH assay is useful in the evaluation of solitary thyroid nodulesBenign = low serum TSHMalignant = cannot be determined
21SERUM THYROGLOBULIN Not helpful diagnostically Elevated in most benign thyroid conditionsOther thyroid function tests are usually not necessary in the initial workup
22SERUM CALCITONINElevated levels are highly suggestive of medullary thyroid carcinoma (MTC)Once the mainstay in the diagnosis of FMTCReplaced by sensitive polymerase chain reaction (PCR) assays for germline mutations in the RET proto-oncogeneCurrently used as tumor markers to monitor patients who have been treated for MTC
24Surgical Treatmentthyroid lobectomy, isthmusectomy, and removal of any pyramidal lobe or adjacent lymph nodetotal or near-total thyroidectomyPatients with a nodule that may be papillary cancer should be treated by thyroid lobectomy, isthmusectomy, and removal of any pyramidal lobe or adjacent lymph nodesMost authors agree that patients with high-risk tumors (judged by any of the classification systems discussed above) or bilateral tumors should undergo total or near-total thyroidectomy. When patients are found to have a minimal papillary thyroid carcinoma in a thyroid specimen removed for other reasons, unilateral thyroid lobectomy and isthmusectomy is usually considered to be adequate treatment, unless the tumor has evidence of angioinvasion, multifocality, or positive margins. The optimal surgical strategy in the majority of patients with low-risk (small, unilateral) cancers remains controversial. The focus of the debate centers around outcome data and risks associated with either lobectomy or total thyroidectomy in this group of patients.Proponents of total thyroidectomy argue that the procedure (1) enables one to use RAI to effectively detect and treat residual thyroid tissue or metastatic disease; (2) makes the serum Tg level a more sensitive marker of recurrent or persistent disease; (3) eliminates the contralateral occult cancers as sites of recurrence (because up to 85% of tumors are multifocal); (4) reduces the risk of recurrence and improves survival; (5) decreases the 1% risk of progression to undifferentiated or anaplastic thyroid cancer; and (6) reduces the need for reoperative surgery with its attendant risk of increased complication rates.32Investigators that favor lobectomy argue that (1) total thyroidectomy is associated with a higher complication rate than lobectomy; (2) recurrence in the remaining thyroid tissue is unusual (5%) and most are curable by surgery; (3) tumor multicentricity seems to have little prognostic significance; and (4) patients who have undergone lesser procedures, such as lobectomy, still have an excellIf intraoperative frozen-section examination of a lymph node or of the primary tumor confirms carcinoma, completion of total or near-total thyroidectomy should be performed
25Non- Surgical approach External Beam Radiotherapy and ChemotherapyRadioiodine TherapyTSH Suppresion TherapyExternal beam radiotherapy is occasionally required to control unresectable, locally invasive or recurrent disease42 and to treat metastases in support bones to decrease the risk of fractures. It also is of value for the treatment and control of pain from bony metastases when there is minimal or no RAIU. Single and multidrug chemotherapy has been used with little success in disseminated thyroid cancer. Adriamycin and Taxol are the most frequently used agentsRADIOIODINE TREATMENTWell-differentiated thyroid cancer still incorporates radioiodine, though less efficiently than normal thyroid follic- ular cells. Radioiodine uptake is determined primarily by expression of the NIS and is stimulated by TSH, requiring expression of the TSH-R. The reten- tion time for radioactivity is influenced by the extent to which the tumor retains differentiated functions such as iodide trapping and organification. After near-total thyroidectomy, substantial thyroid tissue often remains, particularly in the thyroid bed and surrounding the parathyroid glands. Consequently, 131I ablation is necessary to eliminate remaining normal thy- roid tissue and to treat residual tumor cells.IndicationsThe use of therapeutic doses of radioiodine remains an area of controversy in thyroid cancer management. However, postoperative thyroid ablation and radioiodine treatment of known residual PTC or FTC clearly reduces recurrence rates but has a smaller impact on mortality, par- ticularly in patients at relatively low risk. This low-risk group includes most patients with stage 1 PTC with primary tumors <1.5 cm in size. For patients with larger papillary tumors, spread to the adjacent lymph nodes, FTC, or evidence of metastases, thyroid ablation and radioiodine treatment are generally indicated.As most tumors are still TSH-respon- sive, levothyroxine suppression of TSH is a mainstay of thyroid cancer treat- ment. Though TSH suppression clearly provides therapeutic benefit, there are no prospective studies that identify the optimal level of TSH suppres- sion. A reasonable goal is to suppress TSH as much as possible without subjecting the patient to unnecessary side effects from excess thyroid hor- mone, such as atrial fibrillation, osteopenia, anxiety, and other manifesta- tions of thyrotoxicosis. For patients at low risk of recurrence, TSH should be suppressed into the low but detectable range (0.1–0.5 IU/L). For patients at high risk of recurrence or with known metastatic disease, complete TSH suppression is indicated if there are no strong contraindications to mild thyrotoxicosis. In this instance, unbound T4 must also be monitored to avoid excessive treatment.
26How would you manage the patient. Immediate postop How would you manage the patient? Immediate postop? In the next 4 to 6 weeks? Long term plans?
27Total Thyroidectomy vs. Less than Total Thyroidectomy Surgical TreatmentTotal Thyroidectomy vs. Less than Total ThyroidectomyINDICATIONS for TOTAL THYROIDECTOMYPatients older than 40 years withpapillary or follicular carcinoma2) Anyone with a thyroid nodule with ahistory of irradiation3) Patients with bilateral disease
28Postoperative therapy Radioiodine Therapy- 75% of patients with metastatic differentiated thyroid CA can be detected and treated by 131IExternal 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
29Follow-Up -Initially at 6-month intervals 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 thereafterThyroglobulin 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
30Imaging -6 to 12 months after remnant ablation with high or intermediate risk6 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
31Complications of Radioactive Iodine Therapy (131I) and Doses at Which They Are Observed AcuteLong termNeck pain, swelling, and tendernessHematologicBone marrow suppression (>500 mCi)Leukemia (>1000 mCi)Thyroiditis (if remnant present)FertilityOvarian/testicular damage, infertilityIncreased spontaneous abortion rateSialadenitis (50–450 mCi), taste dysfunctionPulmonary fibrosisHemorrhage (brain metastases)Chronic sialadenitis, nodules, taste dysfunctionCerebral edema (brain metastases, 200 mCi)Increased risk of cancer: Anaplastic thyroid cancer, Gastric cancer, Hepatocellular cancer, Lung cancer, Breast cancer (>1000 mCi), Bladder cancerNausea and vomiting (50–450 mCi)HypothyroidismBone marrow suppression (200 mCi)