Endocrinology Flashcards
Neck swellings
A 56-year-old lady complains of an intermittent swelling under her jaw on the left side. The swelling increases in size and becomes painful when she eats.
A Anaplastic carcinoma of thyroid B Benign tumour of parotid (pleomorphic adenoma) C Branchial cyst D Papillary carcinoma of the thyroid E Pharyngeal pouch F Riedel's thyroiditis G Solitary thyroid nodule H Submandibular calculus I Thyroglossal cyst J Virchow's node
Submandibular calculus
This is a typical history of a submandibular stone. On eating, the salivary glands are stimulated to produce saliva. As there is a calculus present in the duct the gland swells because it is obstructed. This occurs most commonly in the submandibular gland. The stone may be palpable in the floor of the mouth.
Neck swellings
A 70-year-old lady presents with a two month history of a swelling in the front of the neck. There has been a rapid increase in the size of the lump. She has become hoarse. On examination she is noted to have an audible wheeze and there is a large hard mass in the lower anterior part of the neck.
A Anaplastic carcinoma of thyroid B Benign tumour of parotid (pleomorphic adenoma) C Branchial cyst D Papillary carcinoma of the thyroid E Pharyngeal pouch F Riedel's thyroiditis G Solitary thyroid nodule H Submandibular calculus I Thyroglossal cyst J Virchow's node
Anaplastic carcinoma of thyroid
This is a very short history of two months. The rapid increase in size suggests malignancy. The other features which are compatible with this are the hoarse voice due to involvement of the recurrent laryngeal nerve.
The audible wheeze will also be due to pressure on the trachea and paralysis of the recurrent laryngeal nerve will also have effects on the vocal chord. The hard mass in the lower anterior part of the neck is suggestive of anaplastic carcinoma.
Riedel’s thyroiditis would also produce a hard, irregular swelling of the thyroid gland, but have a longer history.
Neck swellings
A 60-year-old man presents with a 4 x 2 cm mass to the left of the midline in the lower neck. The mass is oval in shape with a smooth surface. It moves upwards on swallowing.
A Anaplastic carcinoma of thyroid B Benign tumour of parotid (pleomorphic adenoma) C Branchial cyst D Papillary carcinoma of the thyroid E Pharyngeal pouch F Riedel's thyroiditis G Solitary thyroid nodule H Submandibular calculus I Thyroglossal cyst J Virchow's node
Solitary thyroid nodule
This swelling is benign as is it oval and smooth in shape. It is obviously connected with the thyroid because it moves on swallowing.
It is not a thyroglossal cyst because it is to the left of the midline. It is not a branchial cyst because it moves on swallowing.
Neck swellings
A 14-year-old girl presents with a swelling on the left side of the neck. It is painless but has been slowly increasing in size. On examination there is a smooth 5 x 5 cm swelling arising from beneath the anterior aspect of the upper third of the sternomastoid muscle.
A Anaplastic carcinoma of thyroid B Benign tumour of parotid (pleomorphic adenoma) C Branchial cyst D Papillary carcinoma of the thyroid E Pharyngeal pouch F Riedel's thyroiditis G Solitary thyroid nodule H Submandibular calculus I Thyroglossal cyst J Virchow's node
Branchial cyst
This is a branchial cyst, which is usually presents in young people. It may not be apparent until an infection develops; and the classical position is at the anterior aspect of the upper third of the sternomastoid muscle.
Neck swellings
A 65-year-old man presents with difficulty with swallowing, weight loss and vomiting. On examination he is cachexic with a firm swelling in the left supraclavicular fossa.
A Anaplastic carcinoma of thyroid B Benign tumour of parotid (pleomorphic adenoma) C Branchial cyst D Papillary carcinoma of the thyroid E Pharyngeal pouch F Riedel's thyroiditis G Solitary thyroid nodule H Submandibular calculus I Thyroglossal cyst J Virchow's node
Virchow’s node
The history is suggestive of gastric carcinoma at the cardia with secondaries in the supraclavicular nodes, that is, Virchow’s node. The dysphagia, weight loss and vomiting would be compatible with a pharyngeal pouch but this would produce a soft swelling of variable size in the left side of the neck.
Causes of impotence
A 35-year-old male presents with a six month history of reduced libido and impotence. He is rarely aware of any erection and has lost interest in sex. He has been married for 10 years. He has been taking lansoprazole for gastro-oesophageal reflux disease for 18 months. His results show a testosterone of 6.8, a LH of 2.1 and FSH 3 with a prolactin of 1550.
Normal ranges:
Testosterone 10-30 nmol/L
LH 1-10 mu/L
FSH 1-10 mu/L
Prolactin 100-500 mu/L
A Addison’s disease B Haemochromatosis C Klinefelter’s syndrome D Non-functioning pituitary tumour E Primary gonadal failure F Prolactinoma G Psychological H Thyrotoxicosis I Vascular
Prolactinoma
Proalctinoma/microprolactinoma is suggested by the elevated prolactin concentration which is not caused by the drug therapy and the hypogonadotrophic hypogonadism (inappropriately normal LH/FSH - these should rise in the face of a low testosterone but remain in the normal range suggesting a pituitary abnormality).
Prolactinomas are rather unusual in men but do need to be considered.
Causes of impotence
A 23-year-old male presents with a three month history of deteriorating impotence. He is aware of normal morning erections, has normal sex drive but is frequently unable to sustain erections with his newly acquired partner. This is putting a strain on his relationship. He confesses to having smoked the occasional cannabis joint but takes no regular medication. His results show a testosterone of 13.5, LH 3.2, FSH 2.5 and prolactin 335.
A Addison’s disease B Haemochromatosis C Klinefelter’s syndrome D Non-functioning pituitary tumour E Primary gonadal failure F Prolactinoma G Psychological H Thyrotoxicosis I Vascular
Psychological
Psychological impotence is the commonest cause of impotence and the history of normal erectile function with normal early morning erections and intermittent failure of erections.
Although cannabis may cause impotence the past history is not supportive. His results are entirely normal.
Causes of impotence
A Addison’s disease B Drug induced C Haemochromatosis D Klinefelter’s syndrome E Non-functioning pituitary tumour F Primary gonadal failure G Prolactinoma H Psychological I Thyrotoxicosis J Vascular
Haemochromatosis
There are numerous drug induced causes of impotence.
In the first patient’s case, investigations are normal and therefore it would appear that the bendroflumethiazide is the most probable cause of his impotence.
Haemochromatosis, an autosomal recessive disorder associated with excess iron deposition, is classically associated with arthritis, diabetes and hypogonadotrophic hypogonadism. This is typically due to iron deposition within the pituitary. Primary hypogonadism may also occur.
The normal LH and FSH in the presence of low testosterone indicates hypogonadotrophic hypogonadism as they are inappropriately low for the low testosterone concentration.
Interpreting thyroid function tests
Non-functioning pituitary tumour (NFPT).
A Free T4 12.1 nmol/L, TSH 7.9 mU/L
B Free T4 18.6 nmol/L, TSH 0.07
C Free T4 33 nmol/L, TSH 3.1 mU/L
D Free T4 55 nmol/L, TSH
Free T4 8.2 nmol/L, TSH 2.1 mU/L
A NFPT may be associated with hypopituitarism and secondary hypothyroidism with a low thyroxine (T4) plus normal or low thyroid-stimulating hormone (TSH). If the T4 is low yet the TSH normal then this would suggest that the TSH is abnormally low for the T4 suggesting that the pituitary hypothalamic axis is dysfunctional.
Interpreting thyroid function tests
Subclinical hypothyroidism.
A Free T4 12.1 nmol/L, TSH 7.9 mU/L
B Free T4 18.6 nmol/L, TSH 0.07
C Free T4 33 nmol/L, TSH 3.1 mU/L
D Free T4 55 nmol/L, TSH
Free T4 12.1 nmol/L, TSH 7.9 mU/L
Subclinical hypothyroidism is associated with a normal T4 but elevated TSH. This suggests a developing thyroid failure. The raised TSH signals a reacting pituitary with the elevated TSH endeavouring to increase T4 secretion from the thyroid.
Interpreting thyroid function tests
Subclinical hypothyroidism.
A Free T4 12.1 nmol/L, TSH 7.9 mU/L
B Free T4 18.6 nmol/L, TSH 0.07
C Free T4 33 nmol/L, TSH 3.1 mU/L
D Free T4 55 nmol/L, TSH
Free T4 18.6 nmol/L, TSH 0.07
The converse applies for subclinical hyperthyroidism where pituitary secretion is being inhibited by the excessive for the individual (although still in normal range) T4.
10 year survival of thyroid cancer
A 25-year-old man found to have a 1 cm papillary thyroid cancer undergoes a total thyroidectomy. The disease is confined to the thyroid.
A 90%
> 90 %
Papillary thyroid cancer is the commonest type of thyroid cancer (50-60% of all thyroid cancers).
This form is commonest in young adults. Under the age of 40 years in males and 50 years in females the disease tends to have a very good prognosis. Overall the 10 year survival rate is approximately 80%, with the rate being 90-95% in the favourable group with disease confined to the thyroid.
A 32-year-old woman undergoes a total thyroidectomy for a 1.5 cm medullary thyroid carcinoma confined to the thyroid.
50-60%
Medullary thyroid cancer is uncommon (6-8% of all thyroid cancers). Tumour growth is variable. Overall approximately 50% of patients will be alive at 10 years. Approximately 20% of medullary thyroid cancers are familial and are associated with the multiple endocrine neoplasia (MEN) syndromes.
A 72-year-old man is found to have an anaplastic thyroid cancer on fine needle aspiration.
A 45-year-old woman undergoes a total thyroidectomy for a follicular thyroid cancer. No metastases are found on staging.
50-60%
Follicular carcinoma can occur from young adulthood onwards (15-20% of all thyroid cancers). Follicular thyroid cancers tend to spread by the blood stream and may therefore present with metastases. Overall 60 % of patients will be alive at 10 years.
During a thyroidectomy, ligation of the superior thyroid artery at its origin may be associated with damage to which of the following?
External laryngeal Glossopharyngeal (IX) Hypoglossal (XII) Internal laryngeal Recurrent laryngeal
External laryngeal
The external laryngeal nerve descends under cover of the sternothyroid and lies deep to the superior thyroid artery.
It pierces the inferior constrictor of the pharynx and enters the cricothyroid, supplying both of these muscles.
Neck mass
A 4-year-old boy presents with a red tender swelling in the midline, which rises when he protrudes his tongue.
A Branchial cyst B Cystic hygroma C Dermoid cyst D Goitre E Haemangioma F Laryngocele G Sternomastoid tumour H Teratoma I Thyroglossal duct cyst
Thyroglossal duct cyst
The 4-year-old boy has a midline mass. The differential lies between thryoglossal cyst, goitre, dermoid cyst, teratoma or laryngocele. The clinical presentation suggests an infected thyroglossal cyst.
Neck mass
A 2-day-old infant presents with large transilluminating mass in the right posterior triangle of the neck.
A Branchial cyst B Cystic hygroma C Dermoid cyst D Goitre E Haemangioma F Laryngocele G Sternomastoid tumour H Teratoma I Thyroglossal duct cyst
Cystic hygroma
The 2-day-old infant has a mass in the posterior triangle which transilluminates. A cystic hygroma is likely.
Neck mass
A 2-week-old infant is noted to keep her head to the left. On examination she has a palpable lump in the left side of the neck.
A Branchial cyst B Cystic hygroma C Dermoid cyst D Goitre E Haemangioma F Laryngocele G Sternomastoid tumour H Teratoma I Thyroglossal duct cyst
Sternomastoid tumour
The 2-week-old infant has a firm mass in the body of sternocleidomastoid associated with decreased head movement to the contralateral side, a sternomastoid tumour. This responds to stretching exercises.
Neck masses
Neck masses may be congenital or acquired.
Congenital masses may be in the midline, in the anterior triangle, posterior triangle, body or sternocleidomastoid or anywhere.
Masses in the anterior triangle represent branchial cleft cysts.
Haemangiomas can occur anywhere, but are easily identified by their soft, spongy red characteristics.
Surgical glycaemic control
A 36-year-old female with gestational diabetes who is receiving four times daily insulin is to undergo elective caesarian section. Her HbA1c is 6.8%.
A Add glibenclamide B Add long acting subcutaneous insulin C Add metformin D Add short acting subcutaneous insulin E Omit oral hypoglycaemic agent F Continue with current therapy unchanged G Omit current agents H Stop current regimen; start insulin sliding scale
Start insulin sliding scale
When not eating and drinking within 4 hours of surgery and independent of the complexity or length of the procedure in both type 1 and type 2 patients, sliding scale insulin with dextrose infusion (same cannula with volumetric pump) is generally required.
Surgical glycaemic control
A 36-year-old female with gestational diabetes who is receiving four times daily insulin is to undergo elective caesarian section. Her HbA1c is 6.8%.
A Add glibenclamide B Add long acting subcutaneous insulin C Add metformin D Add short acting subcutaneous insulin E Omit oral hypoglycaemic agent F Continue with current therapy unchanged G Omit current agents H Stop current regimen; start insulin sliding scale
Continue with current therapy unchanged
With type 1 patients for minor procedures, they can have their usual morning dose of insulin (plus breakfast) for an afternoon list but this is omitted (as they are starved) for a morning list. Hypoglycaemia is avoided with appropriate dextrose infusion and regular BM checks. (If they have a midday dose of insulin this must be omitted).
Surgical glycaemic control
A 21-year-old female with type 1 diabetes being treated with twice daily insulin is admitted for suction termination of pregnancy on an afternoon operating list.
A Add glibenclamide B Add long acting subcutaneous insulin C Add metformin D Add short acting subcutaneous insulin E Omit oral hypoglycaemic agent F Continue with current therapy unchanged G Omit current agents H Stop current regimen; start insulin sliding scale
Omit oral hypoglycaemic agent
These cases illustrate the importance of appropriate management of diabetic patients undergoing surgery.
For ‘minor’ procedures (defined as eating and drinking within 4 hours of surgery) if patients are taking oral hypoglycaemic agents the drugs are omitted prior to surgery and the procedure performed with close supervision of glycaemic control.
Caesarian sections may be delayed for a variety of reasons and therefore a sliding scale would be appropriate.
A 32-year-old lady who is heavily pregnant presents to her general practitioner as she is concerned about a swelling which has appeared in the anterior part of her neck. She has no previous medical history of note.
On examination, the GP finds a non-tender, smooth, firm and symmetrically enlarged thyroid gland.
Examination of the patient’s thyroid status suggests that she is euthyroid. There are no palpable lymph nodes.
Which one of the following is the most likely diagnosis?
Multinodular goitre Simple goitre Thyroglossal cyst Thyroid malignancy Thyroid nodule
Simple goitre
A simple goitre diffusely affects the whole gland without causing nodularity.
It is caused by a compensatory hypertrophy and hyperplasia of the gland.
A common cause is a physiological goitre due to increased demands for thyroid hormone which can occur in pregnancy.
Other causes include
Dietary iodine deficiency
Treated Graves’ disease and
Hereditary defects in thyroid metabolism.
A simple diffuse goitre can progress to form a multinodular goitre. If this were the case, the goitre would be expected to be asymmetrically enlarged.
Post surgery for a thyroid tumour, a woman develops a hoarse voice.
Her surgeon explains to her that the reason for this is a vocal cord paralysis caused by accidental damage to the recurrent laryngeal nerve.
This has most likely been damaged during ligation of which blood vessel running next to it?
Inferior thyroid artery Inferior thyroid vein Superior thyroid artery Superior thyroid vein Thyroid ima artery
Inferior thyroid artery
The recurrent laryngeal artery is related to the inferior thyroid artery.
The recurrent laryngeal nerve runs in the groove between the trachea and the oesophagus. It enters the larynx deep to the inferior constrictor muscle.
The inferior thyroid artery is a branch of the thyrocervical trunk.
The external laryngeal nerve runs near the superior thyroid artery but is less commonly damaged. Damage to this nerve will generally only lead to a slight hoarseness.
The superior thyroid artery is a branch of the external carotid artery.
A 79-year-old gentleman is admitted with a history of nocturia, frequency, poor flow, hesitancy and terminal dribbling; and retention due to benign prostatic hypertrophy is diagnosed.
Insertion of a catheter drains 2000 ml.
Whilst awaiting urological review, a check U and E has shown that his sodium level has increased from 138 mmol/l on admission to 155 mmol/l (137-144) and his potassium is unchanged at 3.7 mmol/l (3.5-4.9).
He has been normotensive throughout his admission.
What is the likely cause of this finding?
Cardiac failure Cirrhosis Cushing's syndrome Nephrotic syndrome Post-obstruction diuresis
Post obstruction diuresis
The likely diagnosis is post-obstruction diuresis during which, in addition to hypernatraemia, there is also an increased urinary loss of sodium (urinary sodium more than 30 mmol/l).
In Cushing’s syndrome the hypernatraemia is usually associated with hypokalaemia and hypertension and thus is unlikely in this scenario.
The remaining options are all causes of hyponatraemia.
A 31-year-old woman is seen in the clinic complaining of weight loss and palpitations.
On examination she has a tremor and an irregularly irregular pulse. She has a smooth goitre which has a bruit and there is exophthalmos. Thyroid function tests are requested.
Which of the following combinations represents the clinical condition?
T4 ↑; T3 ↑; TSH ↓ T4 ↑; T3 N; TSH ↓ T4 ↑; T3 ↑; TSH ↑ T4 ↓; T3 ↓; TSH ↑ T4 ↓; T3 ↓; TSH ↓
T4 ↑; T3 ↑; TSH ↓
The patient has Graves’ disease and in addition to the T4 ↑; T3 ↑; TSH ↓ pattern will have anti-TSH receptor antibodies.
Other features of Graves’ include:
Heat intolerance Diarrhoea Poor concentration Alopecia Warm flushed skin Hyperreflexia and Pretibial myxoedema Additional eye signs include:
Lid retraction Lid lag Proptosis and Exophthalmos The second profile (T4 ↑; T3 N; TSH ↓) is compatible with a toxic nodular goitre and the third (T4 ↑; T3 ↑; TSH ↑) with pituitary hyperthyroidism. Neither of these will have antithyroid antibodies or exophthalmos.
The fourth profile (T4 ↓; T3 ↓; TSH ↑) is primary hypothyroidism.
The fifth profile (T4 ↓; T3 ↓; TSH ↓) represents secondary hypothyroidism.
A 48-year-old woman is seen in the colorectal clinic with alteration in bowel habit. She also notes a definite weight gain over the past year. Examination of the abdomen is unremarkable. What is the likely diagnosis? (Please select 1 option) Graves' disease Hyperparathyroidism Hypothyroidism Pituitary hyperthyroidism Toxic nodular goitre
Hypothyroidism
Weight gain and constipation are important features of hypothyroidism, whilst others include
Bradycardia Cold intolerance Hyporeflexia Myopathy Weakness Coarse skin Poor memory Hoarse voice. It is essential to examine carefully the neck of patients with constipation, especially if there are no other GI symptoms, and also request a thyroid function test.
A 34-year-old woman who has been on long term steroid immunosuppression following a renal transplant 20 years previously is seen in the clinic.
She is obese with a moon face and has abdominal striae. Routine biochemical tests are requested.
Which of the following is a likely finding given the history?
Hypercalcaemia Hyperkalaemia Hypoglycaemia Hyponatraemia Metabolic alkalosis
Metabolic alkalosis
Cushing’s syndrome is associated with
Hyperglycaemia Hypernatraemia Hypokalaemia Metabolic alkalosis Hypertension.
A 45-year-old man is admitted as an emergency with renal colic.
He has a past medical history which includes renal calculi and acute pancreatitis and is being investigated for bone pain.
Biochemical investigations are requested.
Which of the following is a likely finding?
Deficiency of vitamin D3 Hypercalcaemia Hyperphosphataemia Hypocalcaeima Hypocalciuria
Hypercalcaemia
The clinical history suggests primary hyperparathyroidism which is characterised by the combination of high calcium and low phosphate levels as well as hypercalciuria.
The diagnosis is confirmed by measuring parathyroid hormone (PTH) which will be markedly elevated.
Vitamin D3 levels should not be affected in this condition.
A 56-year-old woman with a longstanding history of chronic renal failure who has been on haemodialysis for five years complains of bone pain affecting her left hand.
An x ray is performed and is reported as demonstrating osteitis fibrosa cystica.
What is the clinical diagnosis?
Osteoarthritis Osteoporosis Paget’s disease Primary hyperparathyroidism Secondary hyperparathyroidism
Secondary hyperparathyroidism
Secondary or renal hyperparathyroidism is a common finding in chronic renal failure.
It is associated with hypocalcaemia and hyperphosphataemia and in most cases it may be managed with phosphate binders and calcium supplementation. If surgery is required then a subtotal parathyroidectomy is the procedure of choice.
Osteitis fibrosa cystica is a radiological feature of severe hyperparathyroidism (primary or secondary), subperiosteal erosion being a more common feature.
Thyroid disease A Graves' disease B Multinodular goitre C Thyroiditis D Thyroxine overdose E Toxic thyroid adenoma In the following cases, select the most likely diagnosis: Normal ranges T4 9-22 T3 3.5-5.5 TSH 0.35-5
A 56-year-old housewife presents with weight loss, sweating and a goitre. Clinical examination reveals a heart rate of 100 bpm, a moderate goitre with no retrosternal extension. Examination of the eyes reveals lid retraction and lid lag. Free T4 is 36.7 pmol/l and TSH
Toxic thyroid adenoma
The 56-year-old housewife has thyrotoxicosis with increased focal uptake on uptake scintigraphy indicating a toxic adenoma.
