Endocrine Pathology Flashcards
What is the location of the pituitary gland?
Situated in the Sella Turcica beneath the hypothalamus
What is the relevant anatomy of the pituitary gland?
- Consists of two parts; Anterior and Posterior
- 75% of the gland formed by anterior lobe formed by outpouching of the oral cavity ( Rathke’s pouch) ( Adenohypophysis )
- 25% posterior lobe formed by down growth of the hypothalamus ( Neurohypophysis )
What are the causes of anterior pituitary hypofunction?
- Tumours - Non-secretory adenoma, metastatic carcinoma
- Trauma
- Infarction
- Inflammation – granulomatous, autoimmune, other infections
- Iatrogenic
What are the features of primary pituitary tumours?
- Vast majority are adenomas and benign
- May be derived from any hormone producing cell
- If functional clinical effect secondary to hormone being produced
- Local effects due to pressure on optic chiasma or adjacent pituiary
Name the types of anterior pituitary adenoma?
- Prolactinoma – Commonest, galactorrhoea and menstrual disturbance
- Growth hormone secreting – Gigantism in children, acromegaly in adults
- ACTH secreting – Cushing’s syndrome
Describe the structure of the thyroid gland.
Bilobed organ joined by an isthmus encased in thin fibrous capsule located at the level of 5th, 6th and 7th vertebra in the anterior neck in close proximity to the trachea.
What is the average weight of the thyroid?
Average weight 18g for adult males, 15g for adult females.
Describe the relationship between the thyroid, the thyroid cartilage and the laryngeal nerve?
Abuts the thyroid cartilage of the larynx, recurrent laryngeal nerve located in the tracheo-oesophageal groove close to posterior aspects of lateral lobes.
Describe the development of the thyroid gland?
- Main part migrates from foregut to anterior neck ( remnant is foramen caecum at junction ant 2/3 and post 1/3 of tongue )
- Ultimobranchial body forms in branchial arches and fuses with main bit laterally
What is thyroid ectopy?
- Thyroid tissue in an abnormal place
- From Foramen cecum to suprasternal notch.
- > 75% of patients with lingual thyroid have no other thyroid tissue. 70% hypothyroid; 10% with cretinism.
- Other sites: Sella turcica, larynx, trachea, aortic arch, esophagus, heart, pericardium, liver, GB, pancreas, vagina.
What is a thyroglossal duct cyst?
- Persistent track representing the embryological migratory path of thyroid anlage in the anterior neck.
- Approximately 7% of adults.
- 75% in anterior midline of neck at or immediately below hyoid bone.
- Most common in children and young adults.
- Asymptomatic midline neck mass.
What is the treatment for thyroglossal duct cyst
4-6% recurrence rate with Sistrunk procedure.
What is acute thyroiditis?
- Acute inflammation of the thyroid parenchyma associated with local or systemic viral, bacterial or fungal infection.
What is the usual cause of acute thyroiditis?
- Most cases due to generalised sepsis.
What are the symptoms of acute thyroiditis?
Fever, chills, malaise, pain, swelling of anterior neck.
What is palpation thyroiditis?
- Microscopic granulomatous foci centred on thyroid follicles.
- Secondary to rupture of thyroid follicles due to palpation or surgery.
- Patients almost always have a thyroid nodule.
What is riedel thyroiditis?
Rare fibrosing form of chronic thyroiditis.
Fibrosing disorder may also affect retroperitoneum, lung, mediastinum, biliary tree, pancreas, kidney, subcutis.
What are the symptoms of riedel thyroiditis?
- Present with firm goitre.
- Symptoms include dysphagia, hoarseness, stridor.
- May be mistaken for malignant neoplasm.
- Benign self-limited disease.
What is chronic lymphocytic thyroiditis?
- Hashimoto’s
- Present with firm goitre.
Symptoms include dysphagia, hoarseness, stridor.
May be mistaken for malignant neoplasm.
Benign self-limited disease.
What is the peak age for Hashimoto’s?
59
What are the features of Hashimoto’s?
- Diffusely enlarged non-tender gland.
Serum thyroid antibodies elevated. - Lymphocytic infiltration of thyroid parenchyma, often with germinal centre formation.
What are the symptoms and risks associated with Hashimoto’s?
- Many patients become hypothyroid.
80-fold increased risk of thyroid lymphoma. - Increased risk of papillary carcinoma of the thyroid.
What is diffuse hyperplasia of the thyroid?
An autoimmune process results in clinical hypothyroidism and diffuse hyperplasia of the follicular epithelium.
aka Grave’s disease
Causes hyperthyroidism
What is the epidemiology of Grave’s disease?
- Incidence 1% world wide.
- Responsible for 80% of cases of hyperthyroidism.
- Females much more common than men.
- Peak in third and fourth decades.
What are the physical findings in Grave’s disease?
- Pretibial myxoedema
- hair loss
- wide-eyed stare or proptosis
- tachycardia
- hyperactive reflexes.
- Thyroid diffusely enlarged.
What are the blood findings in Grave’s?
- T3 and T4 elevated.
- TSH markedly suppressed.
- Thyroid autoantibodies, especially thyroid stimulating immunoglobulin.
What is multinodular goitre?
- Enlargement of thyroid with varying degrees of nodularity.
- 1 or more thyroid nodules discovered by patient or health care provider.
- Most patients are euthyroid.
- Dominant nodule may be mistaken clinically for thyroid carcinoma.
- Tracheal compression or dysphagia may develop with large nodules.
What is follicular adenoma?
- Benign encapsulated tumour with evidence of follicular cell differentiation.
- Painless neck mass, often present for years.
- Solitary nodule involving only one lobe.
- Usually cold nodule on radioactive iodine imaging.
What is the epidemiology of follicular adenoma?
- Females more than males.
- Wide age range, usually fifth to sixth decade.