Goiter - الأهلية

Classification of Goiter

• Cretenoid goiter causes hypothyroidism

• Diffuse hyperplastic goiter may be physiological or due to colloid

• Simple nodular goiter may be a solitary thyroid nodule or multi-nodular

• Toxic goiter occurs:

  • First from diffuse toxic (Grave's)
  • Second from toxic nodular (Plummer's)
  • From toxic nodule

• Inflammatory goiter types:

  • Acute bacterial thyroiditis
  • Subacute thyroiditis (De Quervain's)
  • Autoimmune (Hashimoto's)
  • Riedl's thyroiditis
  • Chronic goiters due to tuberculosis and syphilis

• Neoplastic goiter can be:

  • Benign (adenomas)
  • Malignant, either primary or secondary
    • Primary types are Papillary, Follicular, Medullary, or Anaplastic
    • Secondary

• Amyloidosis is another miscellaneous cause of goiter

Simple Goitre

• Also known as euthyroidism
• NOT toxic, inflammatory, or neoplastic

Physiological Goitre

• Goiter may be related to:

  • Puberty
  • Pregnancy
  • Lactation
  • Menstruation
  • Menopause

• Causes smooth uniform enlargement

• Pathogenesis involves hypertrophy and hyperplasia of thyroid follicles, with gland function remaining normal

• Only symptom is swelling or fullness of the neck (Venus neck)

• Thyroid function tests are within normal limits

• Treatment involves small doses of Eltroxin (100 µg = 0.1 mg / day)

• Usually disappears spontaneously when stress periods are over

Colloid Goitre

• Present in endemic areas

• Pathogenesis stems from iodine deficiency in water and food or a sudden fall in TSH indicating shock dose of iodine

• Pathology shows:

  • Enlarged acini filled with colloid
  • Flattened epithelial lining

• Symptoms include neck swelling and pressure

• Signs are a uniformly enlarged, smooth, and elastic gland

• Medical treatment includes:

  • L-thyroxine at 0.2 mg/day, reduced to 0.1 mg/day as the gland size decreases

• Surgical Options are near-total or subtotal thyroidectomy in cases of:

  • Pressure manifestations
  • Retrosternal extension
  • Cosmetics

Simple Multinodular Goitre

• Commonest type of goitre

• Epidemiology: Middle age and females are more affected

• Pathogenesis results from fluctuatiions of TSH levels and cycles of hyperplasia and involution

• Complications

  • Secondary thyrotoxicosis (30%)
  • Carcinoma (5%), indicative of the presence of:
    • Follicular type
    • Suspicious criteria such as quick size increase, pressure, pain, and bony metastasis

• Pressure manifestations:

  • Trachea deviation can cause kinking
  • Bilateral compression causes scabbard trachea
  • Anteroposterior compression pushes the trachea against the spine
  • Tracheomalacia: Prolonged compression causes cartilage resorption which may result in collapse after thyroidectomy

• Haemorrhage increases the goitre size

• Sudden pain or impending suffocation in a nodule

• Cystic degeneration of the nodule

• Calcification

• Retrosternal goitre

• Surgical treatment is indicated if the goitre is:

  • Big and causing disfigurement
  • Causing pressure manifestations
  • Suspicious of malignancy
  • For all nodular glands for fear of complications

• Types of surgical treatment include:

  • Hemithyroidectomy
  • Near-total thyroidectomy
  • Total thyroidectomy

TOXIC GOITRE

• 2nd type of goitre

• Etiology:

  • Primary toxic goitre is diffuse toxic goitre or Grave's disease, the results of an autoimmune disease

  • Causes abnormal thyroid stimulated antibodies (Ts Abs) stimulate the thyroid like TSH

    • TSH increases to 1.5-3 hr and LATS increases to 12-24 hr
    • Ts Abs are IgG members, present in about 80% of patient serum

  • Secondary toxic goitre is toxic nodular goiter or Plummer's disease

  • Toxic nodule causes hyperthyroidism from a single hyper functioning nodule

  • Occurs in young patients with symptoms of hyperthyroidism and recent growth of a long standing nodule

• Rare types include:

  • Hashitoxicosis of autoimmune thyroiditis
  • Subacute thyoiditis (De Qurervain's disease): due to thyroxin liberation from destroyed tissue
  • Functioning metastatic thyroid cancer
  • Jod Basedow thyrotoxicosis: large iodide doses given to hyperplastic endemic goitre ⇨ temporary or persistent hyperthyroidism
  • Neonatal thyrotoxicosis: neonates of toxic mothers where antibodies can cross the placenta, disappears in 3-4 weeks
  • Thyrotoxicosis factitia (latrogenic): taking L-thyroxine in doses more than 0.2-0.3 mg/day
  • Struma overii: not Ectopic thyroid tissue but it is apart from ovarian teratoma & it is liable to turn malignant or thyrotoxicosis

Pathology of Toxic Goitre

• Primary Toxic Goitre
  • The gland is symmetrically enlarged and very vascular
  • Cut surface is granular and friable
  • There is a loss of normal bluish glistening appearance due to lack of colloid
  • Acini have diffuse hyperplasia and hypertrophy, with columnar cells and scanty colloid
  • Stroma is very vascular with dense lymphocytic infiltration
  • Occurs in previously normal gland due to Ts Abs
• Secondary Toxic Goitre
  • The gland is asymmetrically enlarged, nodular, firm or soft
  • Cut section displays a 'honeycomb' appearance
  • Nodules are inactive with overactive internodular thyroid tissue (or vice versa)
  • Occurs on top of long standing simple nodular goitre
• Toxic Nodule
  • It is autonomous: not under control of Ts Abs.
  • It is overactive with surrounding tissue suppressed due to reduction of TSH

Clinical Picture

• Type of patients:

  • Primary toxic goitre tends to affect young adult females (20-30 yr)
  • Secondary thyrotoxicosis affects middle aged or elderly females (30-50 yr)

• General manifestations:

  • Metabolic:
    • Rapid weight loss despite increased appetite
    • Intolerance to hot weather (the patient likes winter weather)
    • Excessive sweating
  • Nervous:
    • Irritability and anxiety
    • Insomnia and nightmares
    • Fine tremors of fingers

• Eye manifestations include:

  • Dalrymple's sign: Lid retraction where the patient shows the rim of the sclera when directly looking forwards
  • Stellwag's sign: Staring look with infrequent blinking of the eyelids (normally= 5-8 times/min)
  • Rosenbach's sign: Fine tremors on closure of eyelids
  • Von Graefe's sign: Lid lag on downward movement
  • Technique:
    • Hold an object (pencil) in a horizontal plane at a distance of 30 cm
    • Ask the patient to follow moving objects

• Results

  • Lid lag on downward movement

• Other eye manifestations include:

  • Joffroy's sign: No wrinkling of forehead on looking upwards (due to exophthalmos)
  • Moebius's sign: Lack of maintenance of convergence when looking to near object due to weakness of medial rectus
  • Exophthalmos: Anterior displacement of the eye out of the orbit

• Urinary:

  • Polyuria
    • Fluid intake
    • Metabolism is increased

• Renal blood flow is increased due to hyperdynamic circulation

• Cardiovascular:

  • Symptoms: Palpitation and Exertional dyspnea
  • Signs:
    • Pulse: Tachycardia even during sleep, water-hummer pressure and arrythmia
    • B.P.: Systolic up, Diastolic is normal or decreased (increased pulse pressure)
    • Heart: shows manifestations of heart failure in late cases

• Gastrointestinal: has increased appetite and a loss of weight, and diarrhea

• Genital

  • Libido then impotence (men)
  • Polymenorrhea and menorrhagia and oligomenorrhea (late)

• Musclo-Skeletal:

  • Weakness and wasting of proximal limb muscles due to depletion of muscle glycogen
  • Generalized bone aches due to osteoporosis of bone.

• Cutaneous changes includes -Hair falling

  • warm sweaty hand (neurosis -> hands are cold and sweaty)
  • finger clubbing (Thyroid acropachy)
    • pretibial myxoedema
    • Starts as a shiny red plaque of thickened skin over the chin of the tibia and dorsum of foot and extends to involve the whole leg caused by deposition of mucin like substance under the skin
    • glycosaminoglycans.

• Reticuloendothelial

  • Mild splenomegaly & generalized lymphadenopathy

• Local Manifestations

  • Swelling in the thyroid region -- With attacks of suffocation -Is big or has a retrosternal extension -there is more than 2% chances to not have goitre
    • the patient has masked thyrotoxicosis

• Investigations

  • Clinical Investigations -Sleeping pulse --Count the degree of the pulse during the sleep -Body weight, ECG, BMR

• Labratory investigations -- A) Non Specific: Complete blood work(CBC),check liver function, blood and urine glucose with and lipid. and increase the creatinine to prove all. -- B) Specific: Thyroid Function Test - By Hormonal Test which is represented from the total protein bounds - Normal level should start with total serum to (50-150 N.mol/L) And (8-24 Pico mol/l)

• Estimate TSH - and 3 tests from all TSH with the most one ( Normal Test). But If there is a border Line can start with the Radio active to define a hyperthyroidism test.

• If not go with medical to define of is effective for the T3 If its a good dose then it wont have any thyroid issue

• Thyroid Scanning: - After Oral dose the the radioactivity can assessed the gamma to detect the anatomy of the size

• The exophthalmos and how to prevent them

  • Upper Eyelid Covers in 1/6 of corner from the lower side To examine the test that does this with the eyeball with the meter in millimeters There is also Frazer’s to measure them.

Treatment

• Medical treatment for - Small doses of propyl and preg women should have only a small % of the drugs - the patient wont accept a safe operation without a safe amount Antithyrid drugs: They include block oxidation lodination immunosuppressive action and in addition block conversion of T4 to T3 Propyl: if any sore will have to transfuision for the blood

• Surgical - Recuurence of to toxic and failure - No control for severs is very high for some people

• All 4 of the are required for indication: which are and 2-1 or just the indication has a malignancy symptoms and or all them .and that for surgical symptoms

• Preoperations - Barbiturate is used before the the -inderal (Beta blocker drug) is used to help - iodine used for both and k iodine Is require 2 weeks from neomercasole

Surgical Treatment

• Hemithyroidectomy is best for Solitary toxic nodule

• Subtotal thyroidectomy is best for Multiple toxic nodules where where we leave posteromedial part of gland that is sufficient to maintain patient in euothyroid. it is estimated to be 4 gm on each side = ½ normal lobe

• Near total thyroidectomy: where we leave part of gland that is sufficient to maintain patient in euothyroid, and it is estimated to be 2 gm on each side = ¼ normal lobe

• Total thyroidectomy is indicated in:

• Severe ophthalmopathy.

• Coexisting thyroid cancer.

• MEN II syndrome.

• Patient refuses RAI therapy.

• Patient with life threatening reactions to antithyroid medications such as agranulocytosis or liver failure.

• Postoperative: Continue Inderal for 2 weeks. Continue antithyroid drugs for 1 week (half-life of thyroid hormone is 1 week) • L-thyroxin 0.1 mg/day for 6-12 month (to prevent hypothyroidism &  recurrence) after subtotal thyroidectomy. • L-thyroxin 0.2 mg/day for ever after total thyroidectomy

Radioactive-iodine (RAI) Therapy

• Indications:

1. More effective in primary compared to secondary thyrotoxicosis due to fibrosis.
2. All patients must be > 45 years old because before 45 yr it is carcinogenic.
3. Patient unfit for surgery (elderly or cardiac) and refuses surgery
4. Recurrent toxicity after surgery.
5. Patient unfit for medical treatment (idiosyncrasy to antithyroid drugs).

• Contraindications:

1. Young age < 45 years: Risk of inducing thyroid carcinoma is relative
2. Pregnancy (teratogenicity) and lactation (excreted in milk)is Absolute
3. 2ry thyrtotoxicosis: Irradiation ineffective due to fibrosisis relative
4. lodine allergy.
5. Patient with severe exophthalmos is relative

• Mode of action: Radioactive Iodine 131 I when trapped by the thyroid gland
• It liberates beta rays which destroys thyroid cells without affecting much surrounding tissue because of their low penetrability

Patient should stop all antithyroid drugs 2 weeks before treatment to allow for adequate uptake into the thyroid

• Dose:

  • 10 millicuries of 131I is given orally once for gland 60 gm (160 μCi / 1gm).
  • If no clinical improvement after 3 months, a further dose is given.
  • Its effect appears after 3 months, so we give ATDs concomitantly.

• Complications:

1. Myxoedema (80% after 10 years) due to larger doses
2. Recurrence of toxicity due to smaller doses.
3. Malignant transformation (if given before 45 yr)
4. Fetal abnormalities and cretinoid goiter if given during pregnancy.
5. Malignant exophthalmos if given in severe exophthalmos
6. Hypersensitivity

INFLAMMATORY GOITRE (THYROIDITIS)

• Types :

1. Acute Suppurative thyroiditis

2. Subacute (granulomatous) De Quervain thyroiditis

3. Autoimmune (a) focal (b) Diffuse (chronic lymphocytic thyroiditis) (Hashimoto thyroiditis)

4. Fibrosing: Riedl’s thyroiditis

5. Others:- amyloid

• Acute Suppurative Thyroiditis

• Etiology:

  • Predisposing factors: acute upper respiratory tract infection. -Causative organisms: streptococci, staphylococci, pneumococci and E. coli. -Route of infection: -- Direct (mouth, pharynx or nearby LN) -- Lymphatic and blood spread.

• Pathology the gland is enlarged and edematous and may suppurate

• Clinical Picture Patient is common in childhood and adolescence.

• Symptoms & signs: --General: fever and occasionally rigors. -- Local: Acute onset of thyroid pain with dysphagia and The Abscess formationis unilateral and may extend deep in the neck invading trachea, esophagus and mediastinum.

• Investigations FNAC with smear and culture is diagnostic.

  • Specific antibiotic according to culture and sensitivity test.
  • Drainage of the abscess if it forms.
  • Hemithyroidectomy is rarely required

Subacute Thyroiditis (De Quervain’s, Granulomatous Thyroiditis)

Etiology: Viral infection (Influenza or mumps).

• Pathology

Asymmetrical enlarged

Acute inflammation of the thyroid gland and degeneration of the thyroid follicles Which are surrounded by giant cells forming granulomas

• Clinical Picture
• Type of patient: it is common at age of 20-40 years, female > male.
• Symptoms & signs:

1. Asymptomatic (35%) EXCEPT for the goiter.
2. Acute onset (10%):

• Acute onset of painful and tender goiter with symptoms and signs of thyrotoxicosis which are caused by
• Release of thyroid hormones from disrupted follicles

3. Subacute onset (55%)

• General: Influenza like symptoms (fever - headache - malaise)

• Local: Insidious onset of painful and tender goiter (pain may radiates to ear) & firm irregular gland Remissions & relapses over months It is a self limiting disease leaving a normal thyroid after it subsides

• Investigations

• Increased ESR > 100mm/h associated with a neutrophilia. total leucocytic count 

• Thyroid function tests show T3, T4 and ↓TSH level due to break down of thyroid gland tissue 

• FNAC shows acute thyroid inflammation with giant cells forming granulomas

• Radioactive iodine uptake is zero or very low.

• Prednisone test

• rapid symptomatic response to prednisone

• Treatment

• NSAIDs: for pain & continued for several weeks after remission to prevent recurrence.

• -Predinsolone: 40 mg/day/ 1-2 week and the dose is then gradually decrease Beta blockers: in the initial stage of disease may be useful for relieve of thyrotoxic symptoms. NO place for surgery however thyroidectomy is indicated in recurrent disease or failure to medical treatment for long period

Auto-immune Thyroiditis (Hashimoto’s disease)

• Auto-immune disease due to abnormal formation of Ab against thyroglobulin

1. Antimitochondrial antibodies in 100% of patients Etiology
2. Thyroglobulin antibodies only in 50%
3. Second colloid antibodies and microsomal antibodies.

• Pathology Symmetrical enlargement

And Capsule is not adherent and Cut section: pale-gray, firm, granular and nodular.

Follicles are atrophic and lined by Hürthle, or oxyphil cells which is lymphocyte & plasma cell infiltration and the lymphoid follicles Thyroid tissue degenerates and may be replaced by fibrous tissue

Hypofunction (most common cause of hypothyroidism)

• Malignant transformation: papillary carcinoma, malignant lymphoma.
• Type of patient: it is common at age of 30-60 years, female > male. Symptoms & Signs: signs are a Diffuse, firm, non- that 20% causes with enlargement of the pyramidal Symptoms consist of- Tightness of throat with painless, non-tender goitre ,Compression of trachea and RLN is rare. And Hashitoxicosis which is a Mild hyperthyroidism in early stages of disease followed inevitably by Severe hypothyroidism which consist also of that. However most patients are euthyroid at the time of diagnosis.
• Investigations a Antithyroid is only given if required
• Medical: L-thyroxin 0.3 - 0.4 mg/day for hypothyroidism as replacement therapy Surgical: subtotal thyroidectomy:
• If large and causes marked pressure symptoms or disfigurement.

Suspicious of malignancy.

Etiology

• --A) Medical

Subacute Thyroiditis (De Quervain’s, Granulomatous Thyroiditis)

• Rare Types if the patient - Thyroid function test If they show is low then show test to level with the t3 and t4

Riedl’s (Woody) Thyroiditis

• Etiology
• Unknown May be a part of generalized fibrosclerosis that cause fibrosis in other part of body including Retroperitonium, mediastinum Lacrimal glands and bile duct (sclerosing cholangitis).
• Pathology The condition may be unilateral or bilateral and is Characterized by marked dense, invasive fibrosis
• May extend beyond thyroid capsule and involve surrounding structures such as
• Strap muscle, blood vessels
• Trachea, esophagus and occasionally parathyroid glands.
• Complications that occur from that is. Hypothyroidism and Hypoparathyroidism. , hoarseness of voice, and stridor.Pressure
• Clinical features Rapid enlargement of thyroid gland which is hard , fixed and non- tender.

Investigations

• Thyroid function tests are usually normal.
• FNAC, although open biopsy may be needed.
• Thyroid scan: to show No uptake
  • Medical: L-thyroxin to relieve hypofunctionL- thyroxin 0.3 - 0.4 mg/day Surgical: the mainstay of treatment such as Is the relief in pressure is with that action so the operation would not be effective