Solitary Thyroid Nodule Aisha Abu Rashed Differential Diagnosis

Solitary Thyroid Nodule Aisha Abu Rashed

Differential Diagnosis • Colloid cyst • Hyperplastic nodule • Follicular adenoma • Papillary carcinoma • Follicular carcinoma • Medullary cell carcinoma • Anaplastic carcinoma • Lymphoma • Metastasis

Risk Factor For Malignancy: **** • • Hx head/neck irradiation Family Hx of thyroid cancer Age < 20 or> 70 years Male • Growing nodule (if the rate of growth is rapid, you must rule out a thyroid lymphoma) • Firm or hard consistency • Lymphadenopathy • Fixed • Symptoms of compression in a patient without • comorbid goiter: dysphonia, dysphagia, and cough • U/S features: microcalcifications, marked • hypoechogenicity, irregular margins, absence of • Hypoechoic halo around the nodule, lymphadenopathy,

q Palpable thyroid nodules occur in 4– 8% of adult women and 1– 2% of adult men q Multinodular goitre and solitary nodules sometimes present with acute painful enlargement due to haemorrhage into a nodule q only 5– 10% of thyroid nodules are malignant. q A nodule presenting in childhood or adolescence, particularly if there is a past history of head and neck irradiation, or one presenting in an elderly patient should heighten suspicion of a primary thyroid malignancy

presence of cervical lymphadenopathy also increases the likelihood of malignancy secondary deposit from a renal, breast or lung carcinoma presents as a painful, rapidly growing, solitary thyroid nodule. broad differential diagnosis of anterior neck swellings, which includes lymphadenopathy, branchial cysts, dermoid cysts and thyroglossal duct cysts Serum T 3, T 4 and TSH should be measured in all patients with a goitre or solitary thyroid nodule doubt as to the aetiology of an anterior neck swellin. .

• Overview Nodules can be multiple or single, hot or cold. Most solitary nodules are cold, and most of those are benign. • • , Virtually all hot or purely cystic nodules are benign. . 5% of patients who had neck radiation as a child (especially with > I 00 rads) get malignant nodules (mostly papillary carcinoma), and even more get nonmalignant ones (colloid adenoma)

Here are some helpful generalities: Autonomously functioning nodules ( "hot" nodules) are never malignant. So, a single hot nodule is not evaluated further. Histology from a hot thyroid nodule may be indistinguishable from a follicular thyroid malignancy, which could lead to high false positive rates and possibly unnecessary treatment with surgery or RAT. So, do not ever recommend biopsy for a hot nodule! Never, ever! • The majority of nodules are cold, and the majority of these are benign, but thyroid malignancies also present as cold nodules

Cold nodules in a patient with Graves' still are evaluated because they may be malignant. Multinodular goiters (MNG) can have both hot and cold nodules. (If a hot nodule is hot enough, it becomes a toxic MNG) Evaluate the cold nodules because cold nodules in MNG and solitary cold nodules have the same overall malignant risk. Do not routinely screen for thyroid nodules with U/S unless the patient has risk factors for malignancy; however, all palpable nodules (including MNGs) should be viewed with U/S as a general rule.

Workup of solitary nodules: Start with a good Hx and PE. Then, thyroid U/S (even if the nodule was found on CT or MRI) and a TSH. • Do an FNA. no matter the size or type of nodule or the level of TSH. Note that high levels of TSH correlate with increased likelihood that a nodule is malignanty. Large nodules (> 1 em) usually are biopsied based on size alone (unless the nodule is "hot"). . Do a scintigraphy scan

a palpable nodule and is hyperthyroid, a RAIU and scintigraphy should always precede a thyroid ultrasound (U/S). When a patient presents with a palpable nodule and is hypothyroid or euthyroid, the next step in the workup is to go directly to U/S. Ultrasound (U/S) is used to determine the size and number of nodules, to determine whether a nodule is cystic or solid, to stratify a nodule's malignancy risk (low, medium, or high), to localize a nodule for fine needle aspiration, to follow up a nodule's size over time when malignancy is suspected, and to follow up a patient after thyroid cancer resection

Thyroid scintigraphy with 99 mtechnetium should be performed in an individual with a low serum TSH and a nodular thyroid to confirm the presence of an autonomously functioning (‘hot’) nodule. . ‘Cold’ nodules on scintigraphy have a much higher likelihood of malignancy, but the majority are benign. Fine needle aspiration cytology is recommended are radiologically indeterminate. Fine needle aspiration of a thyroid nodule can be performed in the outpatient clinic, usually under ultrasound guidance. Aspiration may be therapeutic for a cyst. Fine needle aspiration cytology cannot differentiate between a follicular adenoma and a follicular carcinoma

Management. In parts of the world with borderline low iodine intake, there is evidence that levothyroxine therapy, in doses that suppress serum TSH, may reduce the size of some nodules. . Nodules that are suspicious for malignancy are treated by surgical excision, by either lobectomy or thyroidectomy. Nodules that are radiologically and/or cytologically indeterminate are surgically excised. Molecular techniques, improve the diagnostic accuracy of thyroid cytology and for indeterminate biopsy. . . 131 I therapy may also cause some reduction in size of a multinodular goitre. Levothyroxine therapy may shrink the goitre of Hashimoto’s disease, particularly if serum TSH is elevated

Thank You Thank you References= Davidson +medstudy