Goiter and Thyroid Cancer

  • View
    37

  • Download
    1

Embed Size (px)

DESCRIPTION

Goiter and Thyroid Cancer. Hasan AYDIN, MD Yeditepe University Medical Faculty Department of Endocrinology and Metabolism. Definitions. Goiter is a diffuse or nodular enlargement of the thyroid gland resulting from excessive replication of benign thyroid epithelial cells. - PowerPoint PPT Presentation

Text of Goiter and Thyroid Cancer

Goiter and Thyroid Cancer

Goiter and Thyroid CancerHasan AYDIN, MDYeditepe University Medical FacultyDepartment of Endocrinology and Metabolism

Goiter is a diffuse or nodular enlargement of the thyroid gland resulting from excessive replication of benign thyroid epithelial cells.Definitions A thyroid nodule is a discrete lesion within the thyroid gland that is palpably and/or ultrasonog- raphically distinct from the surrounding thyroid parenchyma

Incidentalomas are non-palpable nodules incidentally discovered on USG or other radiological imaging performed for other reasons2Function- Euthyroid - Hyperthyroid- Hypothyroid

ThyroidStructure - Diffuse - Nodular

3PrevalenceLarge population studies-Framingham study showed clinically significant nodules in 6.4% women and 1.5% men ages 30-59 (total 4.2%) but thought to be significantly understated

Ultrasounds- 20% to 76% of females had at least one thyroid nodule on ultrasound

Autopsy surveys show 37 to 57% of patients with thyroid nodules4Rate of Carcinoma in Thyroid NodulesSignificant selection bias in surgical seriesUSA: Pts with nodules were referred to surgery without biopsy and 6.5% of excised nodules were carcinomas

Italy: 2327 pts with nodules were evaluated by FNA and of those 391 were selected for surgery. Carcinomas were found in 5% of totalCauses of Thyroid NodulesBenign- >90%Multinodular goiter (colloid adenoma)Hashimotos (chronic lymphocytic) thyroiditisCysts: colloid, simple, or hemorrhagic-7-14% can be malignant- most commonly papillary ca with a cystic component with most increased size 2-4cm Follicular AdenomaMacrofollicular adenomaMicrofollicular or cellularHurthle-cell (oxyphil cell) adenomas- macro or microfollicularMalignant -about 6%PapillaryFollicularMinimally or widely invasiveOxyphilic typeMedullaryAnaplasticPrimary thyroid lymphomaMetastatic carcinomaNodular Goiter

PathogenesisDyshormonogenesis or severe iodine deficiency

Impaired hormone synthesis

Secondarily and increase in TSH secretion.

TSH induces diffuse thyroid hyperplasia, followed by focal hyperplasia with necrosis and hemorrhage, finally the development of new areas of focal hyperplasia.

A clone of cells that may or may not be able to pick up iodine or synthesize thyroglobulin. PresentationAsymptomaticNeck mass discovered by patient or physicianAbnormal CXRSymptomaticPressure symptomsHoarsenessThyrotoxicosis

Suspicious Nodule or GoiterHigh suspicionFamily history of medullary thyroid carcinomaRapid tumor growthA nodule that is very firm or hardFixation of the nodule to the adjacent structuresParalysis of the vocal cordRegional lymphadenopathyDistant metastasisModerate suspicionAge of either70 yearsMale sexHistory of head and neck irradiationA nodule >4 cm in diameter or partially cysticSymptoms of compression, including dysphagia, dysphonia, hoarseness, dyspnea, and cough Differentiation of Benign & Malign Lesions

EvaluationTSHFT4, T3Radionuclide Scan / RAIUUSCT Scan (without contrast)FNA biopsyFNA EvaluationBiopsy all accessible nodule(s)

Biopsy suspicious nodule(s) cold on scan; firm by palpation; growing in size

Results less reliable in large goiters

Most common diagnosis is colloid noduleFNASimple, safe office procedure

Tissue sample obtained by 25 gauge needle

With experience adequate sample may be obtained in 90 -97% of aspirates of solid nodules

False negative rate (FNA benign but nodule turn out malignant) is 0-5% usually due to sampling error

False positive rates (malignant but turns out benign) 4.5 cmTm invasion into neckAggressive Tm growthAnaplastic transformationAge 40 yearsMediastinal LN Mx.Bone Mx.Large solitary pulm Mx.Distant Mx. With no 131I concentrateMost Aggressive

Primary Tm 1.5-4.5 cmMicroscopic multicentric primary Tm.Bilat. Cervical LN Mx.Male genderTm. Occuring after radiotx.Diffuse Pulm Mx. with 131I concentrate

Less Aggressive-Unpredictable Tm BehaviourLymphocytic infiltration of TmPrimary Tm < 1.5 cmEncapsulated Tm.Young patientsThyroglossal duct Tm.Least AggressiveFollicular CarcinomaCharacterized by the presence of small follicles, colloid formation is poor.

Capsular or vascular invasion.

More aggressive and local invasion of lymph nodes or by blood vessel invasion with distant metastases to bone or lung.

Often retain the ability to concentrate radioactive iodine, to form thyroglobulin, and, rarely, to synthesize T3 and T4. Follicular carcinomaMore frequency than papillary cancer in iodine deficiency area.

More frequently with increasing age

Early hematogenous spread to lung, bone, brain, and liver (one fifth of patients ).

Lymph node involvement :less than 1%Follicular CarcinomaRare ''functioning thyroid cancer'' is almost always a follicular carcinoma.

More likely to respond to radioactive iodine therapy.

In untreated patients, death is due to local extension or to distant bloodstream metastasis with extensive involvement of bone, lungs, and viscera. Follicular Ca.-Prognostic factorsPrimary Tm > 4 cmTm invasion into neckModerate to extensive vasc. and capsular invasionOxyphilic Tm (Hurtle Cell)Age 40 yearsMale genderAnaplastic transformationDistant Mx. Most AggressiveMedium sized or large Tm folliclesMinimal capsular or vasc. Tm. invasionLeast AggressiveTm Behaviour38Medullary Carcinomaa disease of the C cells (parafollicular cells) derived

calcitonin, histaminase, prostaglandins, serotonin, other peptides

more aggressive , but not undifferentiated thyroid cancer.locally into lymph nodes and into surrounding muscle and trachea.

lymphatics and blood vessels and metastasize to lungs and viscera.

Calcitonin and CEA clinically useful markers for diagnosis and follow-up. Medullary CarcinomaAbout 80% are sporadic

The remainder are familial: without associated endocrine disease (FMTC); MEN 2a medullary carcinoma, pheochromocytoma, and hyperparathyroidism; MEN 2B, medullary carcinoma, pheochromocytoma, and multiple mucosal neuromas;MEN 3 : with cutaneous lichen amyloidosis, a pruritic skin lesion located on the upper back. Medullary CarcinomaDiagnosed by fine-needle aspiration biopsy or at surgery , it is essential that the patient be screened for the other endocrine abnormalities found in MEN 2.

Screening : measurement of serum calcitonin after calcium infusion in patients who have demonstrated mutations in the ret proto-oncogene on DNA analysis,

Calcium gluconate IV in a dose of 2 mg/kg over 1 minute, and blood for calcitonin determination is obtained at 1, 2, 3, and 5 minutes after the infusion. Peak values occur 1-2 minutes after injection. Undifferentiated (Anaplastic) CarcinomaSmall cell, giant cell, and spindle cell carcinomas.

Usually occur in older patients with a long history of goiter in whom the gland suddenly -over weeks or months- begins to enlarge and produce pressure symptoms, dysphagia, or vocal cord paralysis.

Death from massive local extension usually occurs within 6-36 months These tumors are very resistant to therapy . LymphomaOnly type of rapidly growing thyroid cancer that is responsive to therapy

As part of a generalized lymphoma or may be primary in the thyroid gland.

Occasionally with long-standing Hashimoto's thyroiditis

Characterized by lymphocyte invasion of thyroid follicles and blood vessel walls, which helps to differentiate thyroid lymphoma from chronic thyroiditis.

If there is no systemic involvement, the tumor may respond dramatically to radiation therapy Cancer metastatic to the thyroidCancers of the breast and kidney, bronchogenic carcinoma, and malignant melanoma.

The primary site of involvement is usually obvious,

Occasionally , the diagnosis is made by needle biopsy or open biopsy of a rapidly enlarging cold thyroid nodule.

The prognosis is that of the primary tumor, Management of Thyroid Cancer Papillary and Follicular Carcinoma: Low-risk group under age 45 with primary lesions under 1 cm and no evidence of intra- or extraglandular spread. For these patients, lobectomy is adequate therapy

All other patients high-risk, and for these total thyroidectomy and-if there is evidence of lymphatic spread -a modified neck dissection are indicated.

Prophylactic neck dissection is not necessary.

For the high-risk group, postoperative radioiodine ablationManagement of Thyroid CancerAfter recovery from surgery, liothyronine, 50-100 g daily in divided doses for 4 weeks;

The medication is then stopped for 2 weeks,

The patient is placed on a low-iodine diet.

At the end of the 2-week period, the serum thyroglobulin level is determined and the patient is scanned at 24 and 72 hours after a dose of 2-5 mCi of 131-I.

If there is evidence of residual radioactive iodine uptake in the neck or elsewhere or if there is a rise in serum thyroglobulin greater than 10 ng/ml, radioactive iodine (131 Iodine) is effective treatment.

Management of Thyroid CancerFollow-up at intervals of 6-12 months should include careful examination of the neck for recurrent masses.

If a lump is noted, needle biopsy is indicated to confirm or rule out cancer.

Serum TSH should be checked

Serum Tg should be < 1 ng/ml . Management of Thyroid CancerMedullary Carcinoma: the marker for recurrent medullary cancer is serum calcitonin or CEA

Family members of patients with a genetic ret oncogene mutation should be screened for the mutation.

If a patient a persistently elevated serum calcitonin concentration after total thyroidectomy and regional node dissection, MRI of the neck and chest or selective venous catheterization and sampling for