Case A 42-year-old woman presents with a palpable mass on the left lobe of thyroid gland How to deal with these case?
She has no neck pain and no symptoms of thyroid dysfunction. The patient has no family history of thyroid disease and no history of external irradiation. physical examination reveals a solitary, mobile thyroid nodule, 2 cm by 3 cm, without lymphadenopathy
Which investigations should be performed? Assuming that the nodule is benign ,which, if any, treatment should be recommended?
Anatomy& physiology of thyroid gland
Type of thyroid mass
Approach patient with thyroid nodule
Type of thyroid malignancy
Iodine deficiency disorder (IDD)
Thyroid Anatomy a butterfly-shaped endocrine gland, located on the anterior (front) side of the neck Composed of right & left lob connecting by isthmus supplied with arterial blood from the superior thyroid artery and the inferior thyroid artery
Thyroid mass Nodule cancer goiter
Epidemiology In the United States, 4 to 7 percent of the adult population have a palpable thyroid nodule. Nodules are more common in women and increase in frequency with age and with decreasing iodine intake. The prevalence is much greater with the inclusion of nodules that are detected by ultrasonography or at autopsy. Malignant nodule corresponds to approximately 2 to 4 per 100,000 people per year, constituting only 1 percent of all cancers and 0.5 percent of all cancer deaths.
Causes of thyroid nodules Benign Multi noduler goiter Hashimotosthyrioditis Simple or hemorrhagic cysts Follicular adenomas Sub acute thyrioditis AACE/AME Guidelines 2010
History o Age o Family history of thyroid disease or cancer o Previous head or neck irradiation o Rate of growth of the neck mass o Dysphonia, dysphagia, or dyspnea AACE/AME Guidelines 2010
History o Symptoms of hyperthyroidism or hypothyroidism o Use of iodine-containing drugs or supplements
Most nodules are asymptomatic, and absence of symptoms does not rule out malignancy
Physical Examination A careful physical examination of the thyroid gland and cervical lymph nodes o Location, consistency, and size of the nodule(s) o Neck tenderness or pain o Cervical adenopathy The risk of cancer is similar in patients with a solitary nodule or with MNG (Grade B ) AACE/AME Guidelines 2010
Factors suggesting increased risk of malignant potential (grade C): History of head and neck irradiation Family history of MTC or MEN2 Age <20 or >70 years Male sex Growing nodule Firm or hard consistency Cervical adenopathy Fixed nodule Persistent hoarseness, dysphonia, dysphagia, or dyspnea AACE/AME Guidelines 2010
Laboratory Evaluation • Serum TSH should be tested (grade B) • If TSH level is low (<0.5 μIU/mL), measure free T4 and T3; if TSH level is high (>5.0 μIU/mL), measure free T4 and TPOAb (grade C) • Serum calcitonin should be measured if FNA or family history suggests MTC (grade B) AACE/AME Guidelines 2010
Indication of thyroid ultrasound(grade C)
Palpable thyroid nodule History of neck irradiation Family history of thyroid carcinoma orMEN2 Patient with unexplained cervical lymphadenopathy Not indicated as screening exam AACE/AME Guidelines 2010
Fine-Needle Aspiration Biopsy •Thyroid FNA biopsy has been established as reliable and safe and has become an integral part of thyroid nodule evaluation •Clinical management of thyroid nodules should be guided by the results of ultrasonographic evaluation and FNA biopsy
Sensitivity 83 %
Specificity 92 %
Result of FNA
Thyroid Scintigraphy •Perform thyroid scintigraphy for a thyroid nodule or MNG if the
TSH level is below the lower limit of the normal range (grade B)
In iodine-deficient areas (grade C)
AACE/AME Guidelines 2010
Thyroid Scintigraphy On the basis of the pattern of radionuclide uptake, nodules may be classified as
Hyper functioning (“hot”)
Thyroid Scintigraphy Hot nodules almost never represent clinically significant malignant lesions, whereas cold nodules have a reported malignant risk of about 5% to 15%.
Hot & cold nodule
Thyroid nodule History& physical examination High or normal TSH Low TSH scintigraphy U/S guided FNA cold hot Suspicious Inadequate Benign-ve Malignant +ve Perform FNA benign Observe and repeat FNAC 1 year Or levothroxin Repeat FNA Surgery Surgery
Thyroid Malignancies- Papillary Most common 30% have node metastasis at diagnosis Radiation related Histologically, psammoma bodies distinguish from benign adenoma.
Thyroid Malignancies-Follicular 20 % of malignancies Distinguished from normal follicular adenomas by invasion of capsule or blood vessels. May be difficult to determine on FNA
Thyroid Malignancies- Medullary 5-10% of cases arise from the C cells which produce calcitonin diagnosis based on elevated thyrocalcitonin levels and thyroid nodule (cold)
Thyroid Malignancies- Anaplastic < 10% Highly aggressive with local extension at time of diagnosis. No suitable therapy Prognosis < 1 yr from diagnosis
Iodine Deficiency Iodine is a chemical element. It is found in trace amounts in the human body, in which its only known function is in the synthesis of thyroid hormones Severe iodine deficiency results in impaired thyroid hormone synthesis and/or thyroid enlargement (goiter). More common in female
iodine deficiency disorders (IDDs), include
decreased fertility rate,
increased infant mortality,
pathophysiology Normal dietary iodine intake is 100-150 mcg/d.
Goiter - Patients with IDD most commonly present with goiter
Hypothyroidism - Individuals with severe iodine deficiency may also have hypothyroidism and may complain of fatigue, weight gain, cold intolerance, dry skin, constipation, or depression
Cretinism . Cretinism can be divided into neurologic and myxedematoussubtypes. Both conditions can be prevented by adequate maternal and childhood iodine intake. Neurologic cretinism is thought to be caused by severe IDD with hypothyroidism in the mother during pregnancy and is characterized by mental retardation, abnormal gait, but not by goiter or hypothyroidism in the child. Myxedematous cretinism is considered a result of iodine deficiency and hypothyroidism in the fetus during late pregnancy or in the neonatal period, resulting in mental retardation, short stature, goiter, and hypothyroidism
Physical The first sign of iodine deficiency is diffuse thyroid enlargement, which becomes multinodular over time. In patients with hypothyroidism due to severe iodine deficiency, one might see signs such as dry skin, periorbital edema, and delayed relaxation phase of the deep tendon reflexes.
Laboratory Studies The kidneys excrete approximately 90% of ingested iodine median 24-hour urine iodine collection random urine iodine-to-creatinine ratio
50-100 mcg of iodine per liter mild iodine deficiency
20-49 mcg of iodine per liter moderate deficiency
less than 20 mcg of iodine per liter severe deficiency
The WHO recommendations for iodine intake are 150 mcg/d for adults and adolescents
200 mcg/d for pregnant or lactating women,
Potassium iodide (Lugol solution, SSKI, Pima)
Levothyroxine (Synthroid, Levothroid, Levoxyl)
12.5-50 mcg/d PO and increase by 25-50 mcg/d PO q2-4wk, not to exceed 100-200 mcg/d PO Surgery
Summary Most nodules are asymptomatic, and absence of symptoms does not rule out malignancy The initial evaluation should include measurement of the serum thyrotropin level and a fine-needle aspiration, preferably guided by ultrasonography IDD are common in our region can be preventable by take recommended dose of iodine from natural source