Goitre Flashcards
What is goiter?
Enlargement of the thyroid gland regardless of the cause.
What are the types of goiter?
Simple goiter toxic goiter neoplastic goiter and inflammatory goiter (thyroiditis).
What is simple goiter?
Enlargement of the thyroid gland without toxic neoplastic or inflammatory manifestations.
What is the most common type of goiter?
Simple goiter.
Which gender is more affected by simple goiter?
Females.
What are the types of simple goiter?
Simple diffuse goiter and simple nodular goiter.
What is simple diffuse goiter?
Diffuse enlargement of the thyroid gland.
What is simple nodular goiter?
Enlargement of the thyroid gland with a nodular surface.
What are the causes of simple goiter?
Iodine deficiency stress factors and goitrogens.
How does iodine deficiency cause goiter?
It decreases thyroid hormone synthesis leading to increased TSH which enlarges the gland.
What are examples of stress factors causing goiter?
Puberty pregnancy lactation chronic anxiety and stress.
What are goitrogens?
Substances that decrease thyroid hormone levels such as anti-thyroid drugs and thiocyanates.
How does goiter develop?
Low T3 and T4 lead to increased TSH causing thyroid gland enlargement hyperplasia and increased thyroid follicle formation.
What happens after the cause of goiter is relieved?
The gland undergoes involution and may return to normal.
What is physiological goiter?
A reversible condition where thyroid follicles return to normal size and number.
What is colloid goiter?
A condition where excessive involution leads to increased colloid content inside the follicles with flattened lining cells.
What is simple nodular goiter?
Alternating hyperplasia and involution cause capillary rupture minor hemorrhages fibrosis and nodule formation.
Can the thyroid return to normal in simple nodular goiter?
No because of fibrosis and nodule formation.
What are the general symptoms of simple goiter?
No toxic or malignant symptoms.
What are the local symptoms of simple goiter?
Neck swelling and compression symptoms like dyspnea dysphagia and discomfort in large goiters.
What are the general signs of simple goiter?
No toxic or malignant signs.
What are the local signs of simple goiter?
Butterfly swelling in the lower neck moving with deglutition smooth surface in diffuse goiter and nodular in nodular goiter.
What are the types of nodules in simple goiter?
Single nodule (solitary thyroid nodule) or multiple nodules (multi-nodular goiter).
What are the characteristics of nodules in simple goiter?
Firm fleshy or cystic consistency with no pulsations or thrill.
What investigation confirms the diagnosis of goiter?
Neck ultrasound.
What does neck ultrasound assess in goiter?
Thyroid gland size nodule type (diffuse or nodular cystic or solid) vascularity lymph nodes and retrosternal extension.
What laboratory test is done for goiter?
Thyroid function tests (Free T3 T4 and TSH) which are usually normal.
Why is indirect laryngoscopy done before thyroid surgery?
To assess vocal cord mobility (medicolegal requirement).
What are the complications of simple nodular goiter?
Severe pressure symptoms tracheomalacia toxic change malignant transformation retrosternal extension and cystic changes.
What is tracheomalacia?
Necrosis of tracheal rings due to prolonged pressure from a large goiter.
What is the most common complication of long-standing simple goiter?
Retrosternal goiter.
What percentage of simple nodular goiters become toxic?
0.3
What percentage of simple nodular goiters become malignant?
0.03
How is simple diffuse goiter treated?
Reassurance correction of the cause and low-dose L-thyroxine to reduce TSH release.
What is the treatment for simple nodular goiter?
Subtotal thyroidectomy lobectomy hemi-thyroidectomy or total thyroidectomy.
Why is total thyroidectomy more common than subtotal thyroidectomy today?
It reduces recurrence and ensures complete removal of nodular disease.
What is given after thyroidectomy?
Low-dose L-thyroxine for hormone replacement and to prevent recurrence.
Q: What are the three hormones produced by the thyroid gland
Thyroxine (T4) Triiodothyronine (T3) and Calcitonin.
Q: What is toxic goiter
Thyroid enlargement with hyperthyroidism symptoms.
Q: What are the two types of toxic goiter
Primary toxic goiter (Graves’ disease) and Secondary toxic goiter (Plummer’s disease).
Q: What causes primary toxic goiter (Graves’ disease)
Autoimmune Long-Acting Thyroid Stimulators (LATS) increase thyroid size vascularity and function leading to excess T3 and T4.
Q: What causes secondary toxic goiter (Plummer’s disease)
A simple nodular goiter becomes hyperactive producing excess T3 and T4.
Q: What are the key autoimmune effects in Graves’ disease
True exophthalmos (eye bulging) and pre-tibial myxedema (skin thickening on legs).
Q: What is the main difference between primary and secondary toxic goiter
Primary has sudden onset true exophthalmos and more nervous symptoms while secondary has gradual onset false exophthalmos and stronger cardiovascular effects.
Q: What are the cardiovascular symptoms of toxic goiter
Palpitations tachycardia high-volume pulse arrhythmias and heart failure in severe cases.
Q: What are the neurological symptoms of toxic goiter
Insomnia irritability tremors sweating hyperactivity and muscle weakness.
Q: What are the metabolic symptoms of toxic goiter
Weight loss despite increased appetite hot intolerance and increased basal metabolic rate.
Q: What are the gastrointestinal symptoms of toxic goiter
Increased appetite and diarrhea.
Q: What are the key eye signs in Graves’ disease
Exophthalmos Von Graefe’s sign (lid lag) Stellwag’s sign (infrequent blinking) and Möbius sign (weak eye convergence).
Q: What happens to thyroid hormone levels in toxic goiter
T3 and T4 increase while TSH decreases to near zero.
Q: What does a thyroid ultrasound show in toxic goiter
Increased gland size smooth or nodular surface and hypervascularity.
Q: What does a thyroid scan show in toxic goiter
Diffuse increased uptake in primary goiter and a hot nodule in toxic nodular goiter.
Q: What are the treatment options for toxic goiter
Medical treatment antithyroid drugs beta-blockers radioactive iodine and surgery.
Q: What are the indications for medical treatment
Primary thyrotoxicosis recurrent cases refusal or contraindication for surgery and preoperative preparation.
Q: What are the two main antithyroid drugs
Carbimazole and Propylthiouracil (PTU).
Q: How does radioactive iodine treat toxic goiter
It destroys thyroid follicles by emitting radiation inside the gland.
Q: When is surgery recommended for toxic goiter
Failure of medical treatment toxic nodular goiter solitary toxic nodule or retrosternal goiter.
Q: What are the complications of thyroid surgery
Accidental removal of parathyroid glands causing tetany and nerve injury affecting the recurrent or external laryngeal nerve.
