Endocrine pathology

Question 1

10197 – Concerning thyroid gland swellings
1: an enlarged gland may extend down into the superior mediastinum
2: the ‘lateral aberrant thyroid’ is a solitary nodule in one lobe of the gland
3: the most frequent cause of a solitary thyroid nodule is papillary carcinoma
4: Hashimoto’s disease can present as a solitary thyroid nodule
5: the lymphatic drainage of the thyroid is confined to the internal jugular chain of nodes

Answer 1

TFFTF

Question 2

10221 – Which of the following findings suggests that a thyroid mass is malignant?
A. Size greater than 5cm
B. Retrosternal extension
C. Recurrent laryngeal nerve palsy
D. Positive Pemberton’s sign
E. Stridor

Answer 2

C

Question 3

10440 – Primary thyroid hyperplasia does NOT result in an increase of the
A. size of the thyroid gland
B. amount of colloid in the thyroid follicles
C. height of the epithelium of the thyroid follicles
D. vascularity of the thyroid gland
E. serum TSH

Answer 3

B
The thyroid gland is enlarged (A false) and shows increased vascularity (D false). The thyroid epithelium is taller than normal (C false), but the amount of colloid in the thyroid follicles is reduced (B true). TSH levels are suppressed (E false).

Question 4

22429 – Features of secondary hyperparathyroidism may include
1: hyperphosphataemia
2: adjacent areas of vertebral osteosclerosis and osteoporosis
3: aluminium deposition at the site of mineralization
4: reduced intestinal absorption of calcium

Answer 4

TTTT
Robbins 6th ed. Page: 1150; 1228. Review July 2004 re: options 3 & 4.

Question 5

10185 – Secondary hyperparathyroidism has become much more common since the initiation and wide use of maintenance haemodialysis in patients with renal disease. Concerning this problem
1: secondary hyperparathyroidism is commonly associated with renal osteodystrophy
2: persistent and symptomatic hypercalcaemia is an indication for parathyroidectomy if a renal transplant is being considered
3: about 25% of patients with renal osteodystrophy have parathyroid hyperplasia
4: total parathyroidectomy combined with intramuscular autografting of some parathyroid tissue is a valid procedure
5: secondary hyperparathyroidism may cause pain and itching

Answer 5

TTFTT

Question 6

10191 – Concerning a solitary nodule in the thyroid gland
1: a solitary thyroid nodule is more likely to be malignant than is a multinodular goitre
2: low-dose radiation in infancy or childhood is associated with an increased incidence of thyroid cancer later in life
3: a thyroid nodule is more likely to be cancerous in women than in men
4: hot thyroid nodules rarely are malignant
5: thyroid cancer is present in approximately 50% of young patients with solitary cold nodules

Answer 6

TTFTF
All thyroid conditions are 8 times commoner in women than men. However, a solitary thyroid nodule in a male is more likely to be malignant than a solitary thyroid nodule in a female. Whilst hot nodules are unlikely to be malignant on rare occasions they may be so. The incidence of cancer in solitary nodules in young patients and children is greater than in adults, but not as great as 50%.

Question 7

10306 – Concerning follicular adenoma of the thyroid gland
1: adenomas of the thyroid may develop after irradiation of the neck
2: excision of the whole adenoma is sound practice
3: after excision of a follicular adenoma, permanent thyroid hormone replacement is necessary to reduce the incidence of recurrence
4: fine needle aspiration cytology (FNAC) is diagnostic as a method of distinguishing a follicular adenoma from a follicular carcinoma
5: ultrasound using present techniques can differentiate readily between solid adenomas, carcinomas and non-toxic thyroid nodules

Answer 7

TTFFF
Fine needle cytology cannot distinguish adenoma from carcinoma because this diagnosis rests on the histological features of capsular and/or vascular invasion.

Question 8

14838 – Papillary carcinoma of the thyroid
1: generally has an excellent prognosis (~90% twenty year survival)
2: has metastasised to cervical lymph nodes in about 50% of cases by the time of first diagnosis
3: prognosis is worsened by finding co-existent follicular growth pattern
4: has a more sinister course when onset is in the first two decades of life

Answer 8

TTFF
Refer to Robbins, 6th Ed, Ch 26, page 1143,1144
4: Outcome in paediatric patients with recurrence is better

Question 9

10209 – Papillary carcinoma of the thyroid gland
A. is a tumour usually occurring in young adults
B. is three times more common in males
C. usually presents as a diffuse enlargement of one lobe of the thyroid
D. is often associated with distant metastases
E. is usually associated with hyperthyroidism

Answer 9

A

Question 10

2749, 16942 – Papillary carcinoma of the thyroid
1: can be the result of childhood thyroid irradiation
2: may have asymptomatic metastases for many years
3: commonly presents clinically because of metastases
4: when the histology shows an admixture of papillary and follicular growth patterns, behaviour is predictably more aggressive

Answer 10

TTTF
Robbins 5th ed. Chapter: 25 Pages: 1137-1138.
Papillary carcinoma of thyroid has an overall 10 year survival rate of 98%…..10% to 15% have distant metastases. In gerneal the prognosis is less favourable….with distant metastases.” (Robbins 6th ed p1144) These figures clearly indicate metastases are compatible with long survival. However, specific mention of lung metastases from papillary thyroid cancer is not detailed in Robbins. While this origin could be inferred from the quote “The lung is frequently the site of metastatic neoplasms. Both carcinomas and sarcomas arising anywhere in the body many spread to the lungs….”. Papillary cancer follows childhood radiation like bills follow credit cards. There is no reason to feel confident that this will not continue. This is an indolent cancer which has been likened in behaviour to endometriosis; metastatic spread is extremely common, sometimes widespread (even to lungs, brain! for many years) with minimal deterioration - however, needless to say, overall these are markers for poorer prognosis. Over half of papillary carcinomas have admixtures of follicular growth. However, long-term follow-up shows that regardless of precise proportions, all neoplasms containing some papillary areas have identical biologic behaviour.

Question 11

10483, 22724 – Medullary carcinoma of the thyroid
1: shows a familial tendency
2: often has a stroma rich in amyloid
3: may secrete calcitonin, 5-hydroxytryptamine and prostaglandins
4: is usually associated with hypocalcaemia

Answer 11

TTTF
Robbins 5th ed. Chapter: 25 Page: 1140.
Medullary carcinoma arises in C cells (parafollicular cells) and produces calcitonin, but there are no outstanding changes in plasma calcium levels (D false). C cells have properties of other APUD cells, having a high content of amines and prostaglandins (C true). Medullary carcinoma has a familial tendency (A true) and is associated with the multiple endocrine neoplasia II syndrome. The reason for stromal amyloid is not understood (B true).

Question 12

22699 – A 30 year old man with medullary carcinoma of the thyroid diagnosed by drill biopsy will have
1: hypothyroidism
2: hypercalcaemia
3: a tendency to tetany
4: high circulating calcitonin levels

Answer 12

FFFT
Ganong 16th ed. CHAPTER: 21 PAGE: 351 & 359

Question 13

20901 – S. Medullary cancer of the thyroid is characteristically accompanied by low serum calcium BECAUSE R. medullary cancer of the
thyroid is a neoplasm of the para-follicular (C) cells of the thyroid

Answer 13

S is false and R is true
Robbins 5th ed. Chapter: 25 Page: 1140

Question 14

16040, 16825, 19773 – The best survival with thyroid neoplasia is seen with
A. sporadic (non-familial) medullary carcinoma
B. giant cell carcinoma
C. follicular carcinoma
D. papillary carcinoma
E. small cell carcinoma

Answer 14

D
Robbins 5th ed. Chapter: 25 Page: 1138. Papillary cancer of the thyroid has a very good medium and even long term outlook, even in the presence of disseminated disease. Familial medullary cancer also has an excellent prognosis; this is not shared by the sporadic (non-familial) form of medullary cancer, which also has marked differences in clinical presentation. Follicular cancer has an outlook somewhere between papillary/familial medullary and the highly malignant giant and small cell (collectively ‘undifferentiated’) forms.

Question 15

10203 – A 25-year-old woman who is 11 weeks pregnant, is diagnosed with thyrotoxicosis. Which is the most appropriate form of initial management?
A. Beta-blocker
B. Anti-thyroid medication (neomercazole)
C. Bilateral subtotal thyroidectomy
D. Total thyroidectomy
E. Radioiodine

Answer 15

A

Question 16

20031 – Hyperplasia of the parathyroid gland occurs in chronic renal disease because there is
A. excessive loss of potassium in the urine
B. excessive loss of calcium in the urine
C. excessive loss of phosphate in the urine
D. excessive loss of sodium in the urine
E. impaired calcium absorption from the gut

Answer 16

E
Robbins 5th ed. PAGE: 1/45, 6 Guyton Chapter: 79 Page: 877.

Question 17

16926 – Multiple endocrine neoplasia syndromes may threaten life because they may cause
1: hypertension
2: inappropriate ADH secretion
3: relentless peptic ulcer syndrome
4: ‘malignant’ thyrotoxicosis (thyrotoxic storm)

Answer 17

TFTF
Phaeochromocytoma is part of the variations on the theme of MEN II. Zollinger-Ellison syndrome is part of MEN I. Inappropriate ADH secretion is seen with bronchial cancer (usually ‘oat cell’ or a variant) or with hypothalamic pathology. Life-threatening thyrotoxicosis is seen only in Graves’ disease, which is not part of MEN.

Question 18

15197, 16936 – Asymptomatic family members of a patient with multiple endocrine neoplasia syndrome MEN II (includes phaeochromocytoma and medullary carcinoma of the thyroid) require clinical follow-up. Effective screening tests include
1: urinary catecholamine estimation
2: plasma calcitonin levels
3: plasma calcium estimation
4: serum ionised calcium/phosphate ratio

Answer 18

TTFF
Refer to Robbins, 6th Ed, Ch 26, page 1166-1167.
Despite the theoretical action of calcitonin on plasma ionised calcium, plasma calcium and phosphate levels are normal in this syndrome, even in the presence of a calcitonin-secreting medullary cancer of the thyroid with metastases. Urinary catecholamine determinations, on the other hand, will often unearth an early phaeochromocytoma.

Question 19

16875 – Neuroblastoma of the adrenal
1: commonly matures spontaneously to form a ganglioneuroma
2: is a cancer of childhood
3: commonly causes hypertension
4: has often metastasised by the time of diagnosis

Answer 19

FTFT
Neuroblastoma has been documented to mature to ganglioneuroma - to find out why is currently akin to the quest for the holy grail! This type of regression/maturation is rare. More than 90% of adrenal neuroblastomas secrete catecholamines, but hypertension is rare.

Question 20

15861 – Individuals with long-standing and poorly-controlled diabetes mellitus are prone to infections with pyogenic organisms because
1: B-cell-mediated immunity is often selectively compromised
2: neutrophil phagocytosis of bacteria is impaired
3: neutrophil reactions to chemotactic stimuli are defective
4: the inflammatory vascular reaction is likely to be reduced

Answer 20

FTTT
Immune response in diabetes may be abrogated to some degree (as in many chronic diseases), but this is not predictable or measurable and is certainly not a defined immunoglobulin deficiency of any sort. However, neutrophil reactivity of virtually all kinds is severely compromised and this, together with the micro (and macro) vascular pathology which characterises diabetes, accounts for the frequency and severity of pyogenic infections. Leukocyte problems are likely to respond to adequate medium-term metabolic control and presumably the same goes for lifetime management in genesis of vasculopathy.

Question 21

15831 – Inflammation and repair are often defective in persons with diabetes mellitus because of
1: impaired neutrophil chemotaxis
2: microvascular sclerosis
3: diminished neutrophil phagocytosis
4: impaired antigen presentation by dendritic cells

Answer 21

TTTF
Neutrophil defects seem to be directly related to the current (ie long term, not minute to minute) control of the metabolic state. All aspects of neutrophil anti-bacterial function seem to be impaired, beginning with endothelial adhesion problems. The microvascular sclerosis (plus atheroma) impairs the microvascular response in terms of vasodilatation and probably endothelial responsiveness as well.

Question 22

15783 – S: The distribution of ischaemic organ damage in diabetics differs from that in patients with non-diabetic vascular disease because R: the pathogenesis of ischaemic damage differs significantly between patients in these two groups.

Answer 22

S is true, R is true and a valid explanation of S
The atherosclerosis is apparently identical in the two groups. However, in diabetics, there is also the microvascular pathology which adds another dimension to the ischaemic problems. In diabetics and non-diabetic ‘ischaemics’, stroke is about equally prevalent; myocardial infarction about 5X and ischaemic lower limb disease about 25X.

Question 23

15686 – Hypercalcaemia is commonly caused by
1: ‘primary’ osteoporosis
2: prolonged dialysis for chronic renal failure
3: renal cell carcinoma
4: acute duodenal peptic ulcer

Answer 23

FTTF
Osteoporosis of ‘primary’ or postmenopausal type is not associated with hypercalcaemia. Peptic ulcer may occur as a result of hyperparathyroidism. Prolonged hypocalcaemia in chronic renal failure leads to secondary hyperparathyroidism and the gland overactivity commonly progresses during prolonged dialysis for chronic renal failure. Renal carcinoma is one of the more common causes of the ‘paraneoplastic’ syndrome of hypercalcaemia probably related to cytokine elaboration by the neoplasm.

Question 24

15548 – Osteoporosis is
1: a condition of bone atrophy
2: a feature of scurvy
3: common in severe thyrotoxicosis
4: associated with a normally calcified osteoid matrix

Answer 24

TTTT
Refer to Robbins, 6th Ed, Ch 28, page 1222-1224. Resolved Nov 2003

Question 25

9765 – In post-menopausal osteoporosis
1: the serum calcium is low
2: activity of bone matrix bound growth factors is decreased
3: parathyroid adenomata are common
4: osteoid matrix of the cancellous compartment of vertebral bodies is reduced

Answer 25

FTFT
Robbins, 6th ed, Ch 28

Question 26

16838 – Cushing’s syndrome may be caused by neoplasms originating in
1: bronchus
2: pituitary
3: oesophagus
4: breast

Answer 26

TTFF
Responses 1 and 2 are straightforward (pituitary as a ‘normal’ producer; bronchus as an ‘inappropriate’ producer). While oesophageal squamous cell carcinoma occasionally is associated with ‘inappropriate hyperparathyroid’ state, it does not cause Cushing’s syndrome. Nor has breast cancer been documented as a cause of ‘inappropriate ACTH production’.

Question 27

5254 – Conn syndrome (primary hyperaldosteronism) may be controlled by
administration of
A. frusemide
B. spironolactone
C. chlorothiazide
D. amiloride
E. fludrocortisone

Answer 27

B
Refer to Ganong, 19th Ed, Ch 38, page 691

Question 28

23044 – Endogenous oestrogens are a likely cause of
1: breast cancer in transvestites
2: coronary artery disease in young women
3: clear-cell adenocarcinoma of the vagina
4: gynaecomastia

Answer 28

FFFT
Robbins 5th ed. PAGE: 385-7; 1109

Question 29

19719 – Each of the following hormones is known to stimulate erythropoiesis EXCEPT
A. androgen
B. erythropoietin
C. glucocorticoids
D. renin
E. thyroxine

Answer 29

D
Walter & Israel CHAPTER: 52 Ganong CHAPTER: 13 PAGE: 384, 385