hllj/quesmed huggingface dataset:
A 51-year-old female presents to general practice with a 3-week history of polyuria. She reports no other urinary symptoms. Examination is normal apart from slightly reduced skin turgor. Further investigation reveals:

* Serum osmolality 312 mOsmol/kg (275-295 mOsmol/kg)
* Urine osmolality 91 mOsmol/kg (50-1200 mOsmol/kg)
* Urine osmolality 760 mOsmol/kg after administration of desmopressin

Which of the following best describes the pathophysiological mechanism behind this patient's condition?

Options:
explanation: This is incorrect, indeed the opposite is happening in this patient. ADH recruits aquaporin-2 channels in the distal tubule and collecting ducts of the kidney, thereby allowing water reabsorption. This patient's urine is too dilute, therefore the problem cannot be caused by increased secretion of ADH. Syndrome of inappropriate ADH secretion (SIADH) is a separate clinical entity characterised by increased ADH secretion causing excessive water retention and subsequently reduced serum osmolality.
name: Increased secretion of ADH
label: c
answer: no
explanation: This patient is suffering from cranial diabetes insipidus. Several factors point towards this diagnosis: polyuria, increased serum osmolality, low urine osmolality, and urine osmolality responsive to desmopressin. Cranial DI occurs due to decreased anti-diuretic hormone (ADH) secretion from the pituitary gland. This results in impaired recruitment of aquaporin-2 channels in the distal tubule and collecting duct, resulting in an inability to concentrate urine.
name: Reduced anti-diuretic hormone secretion from the pituitary gland
label: a
answer: yes
explanation: Primary aldosteronism (AKA Conn's syndrome) is characterised by excess production of aldosterone, causing an excess exchange of potassium for sodium in the nephron. This results in hypernatraemia, hypertension, and hypokalaemia. However, this is unlikely to be the underlying cause as this patient demonstrates low urine osmolality which responds to desmopressin - a hallmark of cranial DI.
name: Excess aldosterone production
label: d
answer: no
explanation: An important polyuria differential, though not the case here. T2DM is characterised by elevated plasma glucose. T2DM does not typically feature elevated serum osmolality combined with reduced urine osmolality and is therefore not the diagnosis.
name: Type 2 diabetes mellitus
label: e
answer: no
explanation: Although this describes one potential mechanism of diabetes insipidus, impaired kidney response to ADH is the hallmark of nephrogenic DI. This patient is instead suffering from cranial DI. The two causes of diabetes insipidus can be differentiated by the desmopressin test. As this patient's kidneys have responded to desmopressin (an exogenous ADH analogue) as indicated by the subsequent significant increase in urine osmolality, renal response to ADH is intact. Therefore the pathology must lie elsewhere, confirming the diagnosis of cranial DI.
name: Impaired kidney response to anti-diuretic hormone
label: b
answer: no

Correct answer: a
A 76-year-old male presents to General Practice with a 3-month history of urinary hesitancy and frequency. He does not report any other symptoms. Digital rectal examination reveals an asymmetrical, hard, nodular prostate. You suspect a diagnosis of prostate cancer and arrange an urgent referral to urology.

Which of the following zones of the prostate is most commonly involved in malignancy?

Options:
explanation: There is no lateral zone of the prostate. The three recognised zones are central, transitional, and peripheral. The fibromuscular stroma of the prostate is sometimes considered the fourth zone.
name: Lateral zone
label: d
answer: no
explanation: The fibromuscular stroma is sometimes considered to be the fourth zone of the prostate. It is situated at the anterior of the gland and merges with the urogenital diaphragm. Prostatic malignancy does not typically arise in the fibromuscular stroma.
name: Stromal zone
label: e
answer: no
explanation: Prostate cancer most commonly arises in the peripheral zone of the prostate (70-80%). The prostate has three zones: central, transitional, and peripheral. The peripheral zone is the largest zone of the prostate, making up approximately 65% of the total volume and lies to the posterior of the gland, anterior to the rectum. Prostate malignancy is most commonly adenocarcinoma.
name: Peripheral Zone
label: a
answer: yes
explanation: Only ~20% of prostate malignancies arise in the transitional zone. The transitional zone encircles the urethra. Although not the most common location for malignancy, the transitional zone is the most common zone for benign prostatic hyperplasia to arise.
name: Transitional zone
label: b
answer: no
explanation: This zone has the lowest occurrence of prostate malignancy, with only ~5% of malignancies occurring in this zone. The central zone surrounds the ejaculatory ducts.
name: Central zone
label: c
answer: no

Correct answer: a
A 24-year-old male is brought to the emergency department by his flatmate. The flatmate reports that he found the patient vomiting and confused 40 minutes ago and immediately brought him to the hospital. On assessment, the patient is confused and is only able to report that he feels nauseous and unwell. You note that his respiratory rate is 27 and his heart rate is 92bpm. You perform further investigations, including an arterial blood gas. The results are as follows:

* pH: 7.48 (7.35 - 7.45)
* Pa02: 14kPa (11 - 13)
* PaCO2: 3.1kPa (4.7 - 6.0)
* HCO3-: 25 (22 - 26)
* Base excess: +2 (-2 - +2)

Which of the following is the most likely cause of this patient's presentation?

Options:
explanation: Loss of HCl (stomach acid) can occur through high volume vomiting and results in the depletion of the body's H+ ions. This can result in a metabolic alkalosis. However, this is an unlikely cause of this patient's presentation as he has presented with a respiratory alkalosis. The ABG results of a metabolic alkalosis appear as follows:

* Elevated pH
* Normal PaO2
* Normal PaCO2 (or increased in compensation)
* Elevated HCO3-
* Elevated base excess
name: Loss of hydrogen ions
label: c
answer: no
explanation: Benzodiazepines suppress the respiratory centres, causing respiratory acidosis. This patient has presented with respiratory alkalosis caused by stimulation of the respiratory centres due to salicylate overdose. Respiratory suppression results in the retention of CO2, which causes acidosis. The ABG results of a respiratory acidosis appear as follows:

* Elevated pH
* Reduced PaO2
* Elevated PaCO2
* Elevated HCO3- if compensated
* Elevated base excess if compensated
name: Benzodiazepine overdose
label: d
answer: no
explanation: Diabetic ketoacidosis (DKA) presents with metabolic acidosis, whereas this patient suffers from respiratory alkalosis, therefore DKA cannot be the cause of this patient's presentation. The ABG results of a metabolic acidosis typically appear as:

* Reduced pH
* PaO2 normal or may be increased if compensation
* PaCO2 normal or may be decreased if compensated
* Reduced HCO3-
* Low base excess
name: Diabetic ketoacidosis
label: b
answer: no
explanation: This patient has presented with a respiratory alkalosis secondary to salicylate poisoning. In the early stages of salicylate poisoning, stimulation of respiratory centres results in respiratory alkalosis as CO2 is blown off before metabolic acidosis manifests later due to the direct toxicity of salicylates. Salicylate poisoning presents with hyperventilation, nausea, vomiting, abdominal pain, tinnitus, confusion, and tachycardia. Severe poisoning can cause cerebral and pulmonary oedema, followed by death.
name: Salicylate poisoning
label: a
answer: yes
explanation: Similarly to benzodiazepine overdose, opiates cause suppression of the respiratory centres. This results in hypoventilation and subsequent CO2 retention, which manifests as respiratory acidosis.
name: Opiate overdose
label: e
answer: no

Correct answer: a
A 32-year-old female presents to General Practice with a 5-day history of dysuria and urinary frequency. Examination reveals suprapubic tenderness.

What is the most likely causative organism of this patient's presentation?

Options:
explanation: Staphylococcus saprophyticus is the second most common cause of urinary tract infection, accounting for 5-20% of cases.
name: Staphylococcus saprophyticus
label: c
answer: no
explanation: Candida is an uncommon cause of lower urinary tract infections UTI). Candida UTI typically only occurs in individuals with indwelling catheters or who are immunosuppressed.
name: Candida
label: d
answer: no
explanation: Pseudomonas aeruginosa is another less common organism implicated in urinary tract infections and may be more likely to cause complicated infections.
name: Pseudomonas aeruginosa
label: e
answer: no
explanation: Proteus mirabilis is an uncommon cause of urinary tract infection and is associated with renal tract abnormalities.
name: Proteus mirabilis
label: b
answer: no
explanation: This patient has a classical presentation of a lower urinary tract infection. NICE estimates that 70-95% of lower urinary tract infections are caused by Escherichia coli. Simple lower urinary tract infections are treated with trimethoprim or nitrofurantoin for 3 days in female patients or 7 days in male patients due to the longer male urethra.
name: Escherichia coli
label: a
answer: yes

Correct answer: a
A 67-year-old patient with stage 5 chronic kidney disease presents to the clinic for a scheduled check-up on his condition. He does not report any symptoms but his blood test results reveal that he has developed a complication of CKD and is at risk of developing renal osteodystrophy as a result. His previous check-up one year ago was normal.

Which of the following sets of results most accurately reflect this patient's condition?

Options:
explanation: This patient has developed secondary hyperparathyroidism as a consequence of his chronic kidney disease. Vitamin D is synthesized in the kidneys and is vital in maintaining calcium homeostasis. When renal function is impaired, the body cannot adequately synthesize vitamin D and the body struggles to absorb sufficient calcium as a result. Furthermore, the dysfunctional kidney cannot excrete sufficient phosphate, which ionizes with calcium in the blood and reduces the amount of free calcium available. These two mechanisms result in low serum calcium, which leads to excess parathyroid hormone production. Secondary hyperparathyroidism is now established. Elevated PTH causes excess mobilization of calcium from bones and subsequent mineral bone disease.
name: Elevated PTH, Low Ca2+, Elevated phosphate, Low vitamin D
label: a
answer: yes
explanation: This blood profile is characteristic of primary hypoparathyroidism. Deficient PTH secretion results in reduced calcium mobilization as well as reduced excretion of phosphate, which ionizes with calcium in the blood and further reduces the availability of free calcium. Primary hypoparathyroidism occurs due to impaired function of the parathyroid gland, for example as a result of iatrogenic causes such as thyroid surgery.
name: Low PTH, Low Ca2+, Elevated phosphate, Normal vitamin D
label: d
answer: no
explanation: This profile of blood test results suggests inappropriately elevated calcium in absence of a parathyroid cause. Further investigation is required to rule out important diagnoses such as hypercalcaemia of malignancy.
name: Low PTH, Elevated CA2+, Low phosphate, Normal vitamin D
label: c
answer: no
explanation: This combination of results is unlikely to occur in a patient suffering from CKD. Elevated PTH concurrent with elevated Ca2+ indicates primary hyperparathyroidism whilst elevated phosphate indicates renal dysfunction. An elevated vitamin D, however, is unlikely to occur in renal dysfunction as the kidney is responsible for synthesizing the vitamin. Therefore this combination of results would not occur in a stage 5 CKD patient.
name: Elevated PTH, Elevated Ca2+, Elevated phosphate, Elevated vitamin D
label: e
answer: no
explanation: This profile suggests primary hyperparathyroidism, which most commonly occurs due to parathyroid adenoma rather than CKD. Primary hyperparathyroidism is characterised by inappropriately elevated PTH - i.e. in the presence of low calcium. This usually occurs due to the presence of an adenoma or carcinoma which uncontrollably excretes PTH.
name: Elevated PTH, Elevated Ca2+, Low phosphate, Normal vitamin D
label: b
answer: no

Correct answer: a
A 60-year-old female presents to General Practice with a suspicious mole on her back which she noticed 2 weeks ago. She is concerned about malignant melanoma.

Which of the following would be most suggestive of a malignant melanoma?

Options:
explanation: Although potentially an alarming symptom, oozing or bleeding only constitutes a minor criterion on the weighted 7-point checklist of pigmented skin lesion assessment.
name: Oozing or bleeding
label: c
answer: no
explanation: A pigmented skin lesion should be assessed using the weighted 7-point checklist. Using this method, a diameter of >7mm is only a minor criterion and therefore less suggestive than major criteria such as a change in size.
name: Diameter > 7mm
label: b
answer: no
explanation: NICE recommend the use of the weighted 7-point checklist for the assessment of skin lesions. The checklist consists of 3 major criteria and 4 minor criteria.

Major criteria:
* Change in size of the lesion
* Irregular shape
* Irregular colour

Minor criteria:
* Diameter > 7mm
* Inflammation
* Oozing or bleeding
* Change in sensation

Of the options, change in the size of the lesion is the only major criterion and is therefore most indicative of melanoma.
name: Change in size
label: a
answer: yes
explanation: Inflammation can be an alarming symptom but is only a minor criterion on the weighted 7-point checklist.
name: Inflammation
label: d
answer: no
explanation: Altered sensation (e.g. numbness or tingling) around the site of a lesion constitutes a minor criterion on the weighted 7-point checklist.
name: Altered sensation on/around the lesion
label: e
answer: no

Correct answer: a
A 13-year-old boy presents to General Practise with his mother, who reports a 2-day history of spots across the back and chest. She also reports that he suffered from a sore throat 2 weeks ago which was treated with antibiotics. On examination, you note multiple small lesions across the boy's torso. They are teardrop-shaped, pink, and scaly in appearance.

[lightgallery]

Which of the following is the most likely diagnosis?

Options:
explanation: Guttate psoriasis is the second most common presentation of psoriasis in children (after chronic plaque psoriasis). It classically occurs 2-4 weeks after a streptococcal infection and manifests as multiple small papules which are pink, scaly, and teardrop shape in appearance. Guttate psoriasis is often the first presentation of psoriasis.
name: Guttate psoriasis
label: a
answer: yes
explanation: Tinea corporis (also known as ringworm) is an unlikely diagnosis here. Tinea corporis is a fungal skin infection caused by *Trichophyton* species and presents with a well-defined ring-shaped lesion which may have pustules or papules. Guttate psoriasis on the other hand presents with multiple, small, tear-drop-shaped scales and characteristically is preceded by streptococcal infection.
name: Tinea corporis
label: e
answer: no
explanation: An important differential, pityriasis rosea is a common skin condition characterised by oval-shaped scaly patches that commonly occur after an upper respiratory tract infection. One of the most important differentiating factors between pityriasis rosea and guttate psoriasis is the presence of a herald patch in pityriasis rosea. A herald patch is a single patch that appears in pityriasis rosea a few days before the onset of more widespread skin involvement.
name: Pityriasis rosea
label: b
answer: no
explanation: Generalized pustular psoriasis (GPP) is a life-threatening dermatological condition. It is a rare form of psoriasis characterized by acute-onset, widespread erythema and the subsequent appearance of non-follicular pustules. GPP also often presents with systemic features such as fever, fatigue, nausea, and tachycardia. Guttate psoriasis, on the other hand, is typically a self-resolving condition that often disappears after several weeks without intervention. Furthermore, GPP does not present with tear-drop lesions, but rather a widespread erythema. It is therefore not the most likely diagnosis.
name: Generalized pustular psoriasis
label: d
answer: no
explanation: Although chronic plaque psoriasis is the most common presentation of psoriasis, it is not the diagnosis here. Chronic plaque psoriasis classically presents with well-demarcated, scaly, erythematous plaques that most commonly manifest over extensor surfaces, the trunk, the scalp, and the buttocks. The tear-drop morphology of the lesions and the history of streptococcal infection suggest guttate psoriasis over chronic plaque psoriasis in this case.
name: Chronic plaque psoriasis
label: c
answer: no

Correct answer: a
A 60-year-old male presents to General Practice with a skin lesion on the back of his neck which he noticed 3 weeks ago. The patient recently returned to the UK after living and working in Spain for 20 years. On examination, you identify a 4mm skin lesion with a red central depression and a pearly rolled border.

[lightgallery]

Which of the following is the most likely diagnosis?

Options:
explanation: Although a very important differential for any suspicious skin lesion, this patient does not have a malignant melanoma. Melanomas have varied appearances which are dependent on classification. The most common type of melanoma is superficial spreading which presents as a flat, irregular pigmented lesion. Other types of melanoma include nodular, lentigo maligna, acral lentiginous, amelanotic and many others. This patient, however, has presented with a classic basal cell carcinoma which can be identified by its central depression, telangiectasia and pearly rolled border in an area of sun-exposed skin.
name: Malignant melanoma
label: c
answer: no
explanation: Actinic keratosis is a premalignant skin condition characterised by the presence of a small, scaly lesion found in an area of sun-damaged skin. Although this patient has the sun exposure risk factor for actinic keratosis, the lesion is not scaled and instead has a central depression and pearly, rolled border which is characteristic of basal cell carcinoma.
name: Actinic Keratosis
label: b
answer: no
explanation: Cutaneous squamous cell carcinoma is a common skin malignancy arising from keratinocytes of the skin. As opposed to this patient's lesion, SCCs present as outwardly growing or sometimes ulcerated skin lesions which may be itchy or tender. SCCs sometimes grow from existing areas of skin trauma and commonly arise from areas of skin damage. However, this patient has presented with a centrally depressed skin lesion featuring a pearly rolled edge which is not found in SCC, therefore the diagnosis must be BCC.
name: Cutaneous squamous cell carcinoma
label: d
answer: no
explanation: A seborrhoeic keratosis (SK) is a common benign skin lesion which classically appears as a well-defined keratinous growth which is often described as having a "stuck-on" appearance. However, this patient has not presented with a keratinous growth, but rather with a centrally depressed lesion with a pearly-rolled border which is much more typical of basal cell carcinoma.
name: Seborrheic Keratosis
label: e
answer: no
explanation: This patient has a classical presentation of basal cell carcinoma (BCC). BCCs typically develop over sun-exposed skin such as the face and neck. There are several types of BCC. The most common is the nodular BCC which classically presents with a central depression with a pearly, rolled border. There may be telangiectasia across the centre. Other types of BCC include superficial, morphoeic, and basosquamous.
name: Basal cell carcinoma
label: a
answer: yes

Correct answer: a
A 51-year-old male attends a regular health check-up as part of his work. He reports no symptoms. Examination and observations are both normal, however, blood glucose testing reveals a fasting blood glucose of 8.2 mmol/L (normal range 3.5-5.5 mmol/L).

Which of the following is the most appropriate next step?

Options:
explanation: Reassurance and discharge are not appropriate in this setting. This patient has presented with an abnormal fasting blood glucose result (>7.0 mmol/L) which requires follow-up before a diagnosis of T2DM can be confirmed or excluded.
name: Reassure and discharge
label: c
answer: no
explanation: Although this patient requires additional investigation before a diagnosis of T2DM can be made, NICE recommend the use of the original abnormal test. In this case, it is therefore recommended to perform an additional fasting blood glucose test.
name: Arrange follow-up HbA1c testing in 2 weeks
label: d
answer: no
explanation: As this patient has presented without symptoms and only one abnormal blood test has been produced, NICE state it is inappropriate to diagnose T2DM in this patient. In asymptomatic patients, two abnormal blood tests are required. In symptomatic patients, only one abnormal blood test is required.
name: Diagnose type 2 diabetes mellitus and discuss treatment options
label: b
answer: no
explanation: NICE recommend that type 2 diabetes mellitus (T2DM) should not be diagnosed in asymptomatic patients based on a single abnormal test. Diagnosis of T2DM requires either presence of symptoms and one abnormal test (i.e. random blood glucose, fasting blood glucose, HbA1c), or two abnormal tests if asymptomatic. This patient has presented asymptomatically and therefore requires an additional abnormal test result.
name: Arrange a follow-up fasting blood glucose test in 2 weeks
label: a
answer: yes
explanation: Although lifestyle modification is an important aspect of T2DM management and should be discussed with all patients, it is not the most appropriate next step in this case. This patient has presented with an elevated fasting blood glucose which requires swift follow-up to confirm or eliminate a diagnosis of type 2 diabetes mellitus.
name: Provide lifestyle advice and follow up in 6 months
label: e
answer: no

Correct answer: a