Histopathology 4 - Endocrine disease Flashcards by Adam Haq

What are the most common causes of hyper- and hypo-pituitarism?

Hyperpituitarism: functional adenoma
Hypopituitarism: nonsecretory adenomas/ ischaemic necrosis (Sheehan)/ surgery

How well did you know this?

Not at all

Perfectly

What are the 3 symptoms of local mass effect of pituitary tumours?

Bitemporal hemianopia
Elevated ICP
Obstructive hydrocephalus

How well did you know this?

Not at all

Perfectly

Recall 4 differentials for primary hyperthyroidism

Grave’s
Hyperfunctioning multinodular goitre
Hyperfunctioning adenoma
Thyroiditis

How well did you know this?

Not at all

Perfectly

What is the cause of secondary hyperthyroidism?

TSH-secreting pituitary adenoma (rare)

NB: Causes NOT associated with thyroid disease
o Struma ovarii (ovarian teratoma with ectopic thyroid)
o Factitious thyrotoxicosis (exogenous thyroid intake)

How well did you know this?

Not at all

Perfectly

How can struma ovarii cause thyroid disease?

Ovarian teratomas can secrete ectopic thyroxine

How well did you know this?

Not at all

Perfectly

What autoimmune condition can cause hypothyroidism?

Hashimoto’s

How well did you know this?

Not at all

Perfectly

Differentiate the type of auto-antibodies involved in Grave’s vs Hashimoto’s

Grave’s: anti-TSH
Hashimoto’s: anti-TPO and anti-TG (thyroglobulin)

How well did you know this?

Not at all

Perfectly

What is the histological appearance of a Hashimoto’s thyroid?

Lymphocyte aggregates and transformed follicular cells

How well did you know this?

Not at all

Perfectly

What are the main symptoms of Hashimoto’s?

Clinically hypothyroid
Painless goitre

How well did you know this?

Not at all

Perfectly

Recall differentials for the cause of hypothyroidism

Postablative
Iodine deficiency
Congenital biosynthetic defect
Autoimmune (Hashimoto’s)

Secondary Causes
o Pituitary or hypothalamic failure (MOST COMMON)

How well did you know this?

Not at all

Perfectly

What is a thyroid adenoma?

Benign neoplasm of follicular thyroid epithelium

How well did you know this?

Not at all

Perfectly

How are thyroid adenomas diagnosed?

FNA and cytology

How well did you know this?

Not at all

Perfectly

What is the most common type of thyroid carcinoma?

Papillary (75-85%)

Follicular (10-20%)
Medullary (5%)
Anaplastic (< 5%)

How well did you know this?

Not at all

Perfectly

What are the key histological features of papillary thyroid cancer?

Optically clear nuclei
Psammoma bodies (little folliculi of calcification)

How well did you know this?

Not at all

Perfectly

Which type of thyroid carcinoma is associated with Multiple Endocrine Neoplasia?

Medullary

Neuroendocrine neoplasm derived from parafollicular C cells (which secrete calcitonin)

- 80% are sporadic in adults (present at 50-60 years)
20% are familial (associated with MEN) which are seen in younger patients*

How well did you know this?

Not at all

Perfectly

Which type of thyroid carcnoma is most aggressive?

Anaplastic

Occurs in elderly patients
It is very aggressive

How well did you know this?

Not at all

Perfectly

What are the 4 subtypes of thyroid carcinoma?

Follicular
Papillary
Medullary
Anaplastic

What is the most common cause of primary hyperparathyroidism?

Solitary adenoma (80-90%)

10-20% are due to hyperplasia of ALL four glands
o Sporadic
o Part of MEN1
- < 1% are due to a carcinoma

What is the most common symptom/finding in hyperparathyroidism?

Clinically silent hypercalcaemia (so not really a symptom)

stones

bones

abdominal moans - constipation, pancreatitis and gallstones

psychic groans - depression, lethargy, fits

What is secondary hyperparathyroidism almost always caused by?

Renal failure

(caused by any condition that causes chronically low calcium)

Recall 3 possible causes of hypoparathyroidism

Surgical ablation - most common
Congenital absence
Auto-immune

Recall 4 possible symptoms of hypoparathyroidism

Those of hypocalcaemia:
Muscle spasms/ tetany
Cardiac arrhythmias
Fits
Cataracts

Mnemonic: CATS go numb (convulsions, arrhythmia, tetany, spasms,
numbness)

Recall the synthetic function of each zone of the adrenals

*Medulla**: Noradrenaline and adrenaline
*Reticularis**: androgens + glucocorticoids
*Fasciculata**: cotrtisol (glucocorticoids)
*Glomerulosa**: aldosterone (mineralocorticoids)

What is Waterhouse-Friedrichson syndrome?

Adrenal insufficiency with sepsis and DIC

What are anterior and posterior pituitary made of?

The anterior pituitary is made up of epithelial cells (from developing oral cavity) The posterior pituitary cells is made up of nerve cells (from supraoptic and paraventricular nucleus)

Hyopthalmic factor for each pituitary hormone?

TRH + TSH PIF (dopamine) - PRL CRH + ACTH GHRH + GH Somatostatin - GH GnRH + FSH/LH

Clinical effects of prolactinoma

Amenorrhoea, galactorrhoea, loss of libido, infertility Usually diagnosed quicker in females of reproductive age Most common pituitary adenoma

Clinical effects of Growth hormone adenoma

Prepubertal children - gigantism Adults - acromegaly o Diabetes, muscle weakness, hypertension, congestive cardiac failure

Clinical Features of Anterior Pituitary Hypopituitarism

Children- growth failure (pituitary dwarfism) - Gonadotrophin deficiency (usually the first manifestation seen in adults) o Amenorrhoea and infertility in women o Decreased libido and impotence in men - TSH and ACTH deficiency (seen later in adulthood) o Hypothyroidism o Hypoadrenalism - Prolactin deficiency- failure of postpartum lactation

What hormones does the posterior pituitary produce?

ADH and Oxytocin

Clinical Features of Posterior Pituitary syndromes

Diabetes insipidus - Produces large amounts of dilute urine o Inappropriately high ADH (SIADH)  Can occur after head injury, brain tumours, serious illness  Typically presents with profound hyponatraemia (due to dilutional effects)

What do parafollicular cells in the thyroid do?

synthesise calcitonin- this promotes absorption of calcium by the skeletal system

Cushings causes?

**Endogenous causes:** * pituitary adenoma - most common * hyperplasia of ACTH-secreting cells in the pituitary rather than a discrete adenoma * ectopic ACTH by non-endocrine tumours (most commonly small cell lung cancer) * In these cases, the adrenals will show bilateral hyperplasia as they are driven by ACTH

Clinical features of cushings?

Hypertension and weight gain Truncal obesity ‘Moon’ facies ‘Buffalo hump’ Cutaneous striae

Hyperaldosteronism causes

35% are due to an adenoma (Conn’s syndrome) – this is primary hyperaldosteronism - 60% bilateral adrenal hyperplasia

Hyperaldosteronism clinical features

Hypertension Hypokalaemia

Congenital Adrenal Hyperplasia causes

Group of autosomal recessive disorders Caused by hereditary defects in enzymes involved in cortisol biosynthesis Reduced cortisol production results in increased ACTH, adrenal stimulation and increased androgen production More commonly presents in childhood (less commonly in adults)

Causes of primary adrenal insufficiency?

**ACUTE**  Sudden withdrawal of corticosteroid therapy  Haemorrhage (into the adrenals) – seen in neonates  Sepsis with DIC (Waterhouse-Friderichson syndrome) **CHRONIC** (Addison’s Disease)  Autoimmune (75-90%)  TB  HIV  Metastatic tumour (lung and breast particularly)  Rarely amyloid, fungal infections, haemochromatosis, sarcoidosis **Secondary to reduced ACTH** o Non-functioning pituitary adenomas (compressing the rest of the pituitary) o Other lesions of pituitary or hypothalamus including infarction

Phaeochromocytoma rule of 10s?

10% arise in association with a familial syndrome, including:  MEN 2A and 2B  Von Hippel Lindau disease  Sturge-Weber syndrome o 10% are bilateral o 10% are malignant o 10% of catecholamine-secreting tumours arise OUTSIDE of the adrenal (paragangliomas) ## Footnote  Tend to occur along the sympathetic chain, along either side of the spine or neck

Multiple Endocrine Neoplasia (MEN) Syndromes causes

- These are a group of inherited diseases resulting in proliferative lesions (hyperplasias, adenomas and carcinomas) of multiple endocrine organs - Tumours can occur at a younger age than sporadic tumours - Arise in ≥ 1 endocrine organ OR may be multi-focal within one endocrine organ - Tumours are often preceded by hyperplasia - Tumours are often more aggressive than sporadic tumours and therefore are harder to treat

Multiple Endocrine Neoplasia (MEN) types

**MEN 1**  Pituitary adenoma  Parathyroid hyperplasia  Pancreatic tumours **MEN 2A**  Medullary thyroid carcinoma  Parathyroid hyperplasia  Phaeochromocytoma **MEN 2B**  Same as 2A  Marfanoid body habitus  Mucosal neoplasms