Case-based MCQ

🇨🇦 MCCQE1,2 | #Case_68 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 75-year-old female presents with a acutely swollen, painful, erythematous left knee. Symptoms have been present for 48 hours. She denies previous episodes and trauma. She admits that she had stopped her ‘thyroid tablets’ a few months ago, as she prefers natural medicines.On clinical examination all vitals are within normal range, and the patient is afebrile. The left knee is visibly inflamed, red, swollen, and very tender to touch. There are no visible areas of penetrative skin trauma. What would be the next appropriate diagnostic step? a) A serum thyroid stimulating hormone (TSH) level and T4 level. Stat dose of 200 micrograms levothyroxine and review in 3 days. b) Immediate referral to an orthopaedic surgeon, as she will probably require an urgent joint replacement c) Obtain a full blood panel including a complete blood count (CBC), serum uric acid, urea and creatinine,C-reactive protein (CRP). Give a high dose anti-staphylococcal antibiotic and high dose oral corticosteroids whilst awaiting results. d) Sterile aspiration of synovial fluid. Request polarized light microscopy. Intra-articular corticosteroid directly post aspiration to provide symptomatic relief. e) Sterile aspiration of synovial fluid. Request urgent microscopy, Gram stain and polarized light microscopy

🇨🇦 MCCQE1,2 | #Case_67 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ B 🔎 Explanation This patient’s clinical picture is suggestive of pleuropulmonary nocardiosis caused by Nocardia asteroides (choice B). It is an acute, subacute, or chronic infectious disease that typically affects immunocompromised hosts, although cases in immunocompetent patients also have been reported. This patient’s long history of inflammatory bowel disease that was most probably treated with immunosuppressive therapy is a typical association with this infection.The disease may present with night sweats, fever, cough, and chest pain. It is characterized by multiple pulmonary infiltrates on chest X-ray with a tendency to central necrosis. Pulmonary infiltrates are often persistent for months as the disease is refractory to antibiotherapy, just as described in this patient. While diagnosis may be challenging, when it is suspected, the organisms can be visualized by a modified Ziehl-Neelsen stain such as Fite-Faraco staining. It is a weakly acid-fast organism. Despite the lack of controlled clinical trials and no general treatment guidelines for norcadiosis, sulfonamides are considered the treatment of choice. Sulfadiazine or trimethoprim-sulfamethoxazole should be given for a period of 6 months. ⚠ Pneumocystis jiroveci (choice A) also could present with cough, fever, and pulmonary infiltrates in immunocompromised patients. Furthermore, the treatment of choice for this infection is trimethoprim-sulfamethoxazole. However, it is visualized on silver-stain and not Ziehl-Neelsen stain, as it is not an acid-fast organism. ⚠ Mycobacterium tuberculosis (choice C) is classified among unusual organisms that may cause persistent pulmonary infiltrates and just as seen in this patient, it can cause night sweats, fever, cough and is an acid-fast organism visualized on Ziehl-Neelsen stain. However, it is best treated with Isoniazid, rifampin, ethambutol, and pyrazinamide. ⚠ Coccidioides immitis (choice D) is a fungus, treated with ketoconazole. ⚠ Mycoplasma pneumonia (choice E) would probably have been cleared with antibiotics given for community acquired pneumonia. It is not an acid-fast organism. ✅Key point: Pleuropulmonary nocardiosis is associated with persistent pulmonary infiltrates and may be refractory to antibiotherapy. It is a weakly acid-fast organism and the first line treatment is sulfonamides (either sulfadiazine or trimethoprim-sulfamethoxazole).

🇨🇦 MCCQE1,2 | #Case_67 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 34-year-old male comes for a follow up of his recent lower respiratory infection treatment. Three weeks ago he had sought medical attention due to 5 days of cough, fever, and night sweats. Chest X-ray had shown pulmonary infiltrates and he was prescribed antibiotics with a presumed community-acquired pneumonia diagnosis. Today he reports that he is still coughing and has been experiencing chest pain. His past medical history is significant for ulcerative colitis, for which he has been receiving treatment for the last 3 years. Chest x-ray repeat shows disseminated pulmonary infiltrates. Laboratory studies reveal weakly acid-fast organisms. Taking his past medical history, current presentation, and all investigation results into consideration, you decide to treat him with trimethoprim- sulfamethoxazole. If his condition improved within the following 3 months, you would assume that the most probable culprit for causing his symptoms was: a) Pneumocystis jiroveci b) Nocardia asteroides c) Mycobacterium tuberculosis d) Coccidioides immitis e) Mycoplasma pneumonia

🇨🇦 MCCQE1,2 | #Case_66 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ E 🔎 Explanation Epiglottitis is an inflammation of the epiglottitis and surrounding supraglottic structures that is typically caused by Haemophilus influenzae type B. Without immediate treatment epiglottitis can progress to life-threatening airway obstruction. On history, muffled voice, high pitched breathing (stridor), inability to swallow food (sore throat), and uncertain vaccination history all put him at significant risk for epiglottitis. The suggestive examination findings include leaning forward, drooling, fever, and tender cervical lymphadenopathy. The treatment is supportive, however, it is imperative that the patient not be disturbed and emergent transfer to a Level 3 facility be arranged for airway support. ⚠ The most common cause of epiglottitis in children is Haemophilus influenzae type B (HiB), which is gram-negative coccobacillus. Although HiB is a common cause in adults, most of time the infection results from several other bacteria (choice A). ⚠ Suggesting rest and hydration is a reasonable option for acute bronchitis (choice B) in selected patients. However, in this patient such a suggestion may result in the patient deteriorating further. ⚠ Oral amoxicillin (choice C) is an inappropriate choice for an emergent case of possible airway obstruction. ⚠ While the appropriate place for this patient is the emergency department, it is inappropriate to simply advise them to seek this on their own (choice D). This can be for various reasons including the patient/mother's incomplete understanding of the gravity of the situation, perceived inconvenience etc. ✅Key point: Epiglottitis must be recognized in a febrile patient with sore throat, muffled voice, and stridor with or without a background history of incomplete immunizations. Unrecognized epiglottitis may rapidly lead to airway compromise and resultant death. Maintenance of the airway is the mainstay of treatment of epiglottitis.

🇨🇦 MCCQE1,2 | #Case_66 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 You are asked to see an 18-year-old man with autism in a busy walk-in clinic who presents with 4 day history of fever, malaise, and sore throat. He has brought his mother in to speak for him. She tells you that he has been making high-pitched sounds during inspiration and spitting out food that he normally enjoys eating due to pain with swallowing. She has also noticed that his voice has been muffled sounding for the last 24 hours.Vital signs: temperature 39.6°C, BP: 96/52 mmHg, HR: 102 bpm, RR: 12 rpm. On examination, you notice him leaning toward you. On examination of his throat you notice pooled saliva in the mouth. He has tender anterior cervical lymphadenopathy. The rest of the physical exam is normal. What is your next step in the management of this patient? a) Reassure the patient and his mother that this is only a viral infection b) Suggest rest, hydration, and close follow-up with their regular family physician c) Prescribe Amoxicillin 400mg TID for 7 days with close follow-up. d) Advise the patient and his mother to go to the emergency department for treatment. e) Ensure the patient is calm, and call 911 for emergent transfer to the nearest emergency department

🇨🇦 MCCQE1,2 | #Case_65 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ B 🔎 Explanation Hypertrophic obstructive cardiomyopathy (HOCM) (choice B) is the most likely cause of the murmur in this patient. HOCM typically presents between 20 and 40 years of age and might be asymptomatic and diagnosed only when the characteristic murmur is found incidentally. Common symptoms include palpitations, angina, syncope or presyncope, shortness of breath with exercise or even sudden death. Physical signs of HOCM include PMI that is displaced laterally and is sustained in nature. Double or triple cardiac impulses are sometimes found. The typical murmur of HOCM is a midsystolic harsh murmur with maximal intensity along the lower sternal border or apex. Unlike most other systolic murmurs, the murmur of HOCM is diminished by squatting and is enhanced by standing because squatting increases venous return and standing decreases it. A high venous return expands the left ventricle including the point of obstruction within the ventricle and thus, softening the murmur in patients with HOCM. Our patient showed most of these and HOCM is thus the most likely cause of murmur. The table below compares the murmur of HOCM to that of aortic stenosis (AS), mitral regurgitation (MR), ventricular septal defect (VSD) and pulmonary stenosis (PS). The peachy color indicates characteristics of the murmur in our patient. ⚠ Aortic stenosis (choice A) is a rather unlikely cause of murmur in this patient. AS might start early in life but most patient develop symptoms in the 6th to 8th decades of life and they usually present with increasing breathlessness on exertion. The murmur of AS is crescendo decrescendo midsystolic murmur with maximum intensity in second intercostal space to the right of sternum and radiates to the clavicle or carotid artery. For all these reasons aortic stenosis is not the likely cause of murmur in this patient. ⚠ Mitral regurgitation (choice C) is an unlikely cause of murmur in this patient. The murmur of MR is a holosystolic rather than midsystolic with maximum intensity at the apex and it usually radiates to axilla. ⚠ Large ventricular septal defect (VSD) with pulmonary hypertension (choice D) usually results in early systolic rather than midsystolic murmur because shunting of blood decreases towards the end of systole. This is because pulmonary hypertension increases right ventricular pressure. Smaller VSDs on the other hand usually cause holosystolic murmurs. Thus, VSD is an unlikely cause of murmur in our patient. ⚠ Pulmonary stenosis (PS) complicated by pulmonary hypertension (choice E) is not the correct choice. In PS the murmur is midsystolic with maximum intensity in the left second intercostal space. Also, this murmur is louder during inspiration. PS is thus, an unlikely cause of the systolic murmur in our patient. ✅Key point: Onset, area of maximum intensity and radiation of a murmur are helpful in identifying its causes. A midsystolic murmur with maximum intensity at apex or along left lower sternal border and that does not radiate is most likely due to HOCM.

🇨🇦 MCCQE1,2 | #Case_65 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 27-year-old man presented to his family physician with palpitations of about two weeks duration. The palpitations were intermittent, short-lasting, resolved spontaneously, and were not related to exertion. He had no other symptoms. His heart rate was regular at 92 beats per minute and other vital signs were stable. Examination showed the following: - point of maximum impulse is located in the 5th intercostal space 1cm lateral to the midclavicular line; - normal first and second heart sounds; - midsystolic harsh murmur of grade VI/6 with maximal intensity at the left lower sternal border and did not radiate to the axilla, clavicle or carotid artery. The murmur was diminished by squatting and was louder during expiration.The rest of physical examination was normal. Which of the following is the most likely cause of this patient's heart murmur? a) Aortic stenosis b) Hypertrophic obstructive cardiomyopathy c) Mitral regurgitation d) Large ventricular septal defect complicated by pulmonary hypertension e) Pulmonary stenosis complicated by pulmonary hypertension

🇨🇦 MCCQE1,2 | #Case_64 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ C 🔎 Explanation A visual field defect of the outer hemi-fields of both eyes (bitemporal hemianopia) indicates a midline lesion that affects the optic chiasm. The visual field defect more pronounced on the upper quadrants (‘pie in the sky’) indicates the optic chiasm is compressed from below. The location of the pituitary gland matches this description. Galactorrhea, amenorrhea, and infertility are seen in hvperprolactinemia, which can be caused by a tumor (adenoma) of the anterior pituitary (choice C). ⚠ Tumors of the sphenoidal ridge (choice A) and olfactory groove (choice B) compresses the optic nerve and mostly causes a monocular visual field deficit (not a bitemporal hemianopia). It also wouldn’t explain the features of hyperprolcatinemia seen in this patient. ⚠ Posterior pituitary (choice D), which stores and releases antidiuretic hormone (ADH) and oxytocin, does not form adenomas. ⚠ Craniopharyngioma is a tumor that arises from the remnants of the Rathke pouch of the pituitary stalk (choice E) and compresses the optic chiasm from above, which results a bitemporal hemianopia with a visual field defect more pronounced in the outer inferior quadrants (not the outer superior quadrant as seen in this patient). ✅Key point: Bitemporal hemianopia points to a lesion compressing the optic chiasm. In a patient with bitemporal hemianopia it is important to look for features of anterior pituitary hormone dysregulation.

🇨🇦 MCCQE1,2 | #Case_64 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 38-year-old female presents to the family physician's office complaining of a ‘whitish’ discharge from her both nipples, which she first noticed one week ago. She has never been pregnant and her last menstrual bleeding was three months ago. On confrontation visual field testing, she has field defects in upper and temporal quadrants of both eyes. A tumor at which of the following location could explain her signs and symptoms? a) Sphenoidal ridge b) Olfactory groove c) Anterior pituitary d) Posterior pituitary e) Pituitary stalk

🇨🇦 MCCQE1,2 | #Case_63 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ B 🔎 Explanation This patient’s clinical scenario is consistent with gallstone ileus (choice B). It is an obstruction of the small bowel (at or near the ileocecal valve) due to impaction of a large (at least 2.5 cm in diameter) gallstone in the ileum after being passed through a biliary-enteric fistula. 60% are cholecystoduodenal fistulas, but cholecystocolonic and cholecystogastric fistulas can also result in gallstone ileus. Gallstone ileus is a complication of cholelithiasis and gangrenous gallbladder. It presents with intermittent abdominal pain that is poorly localized, abdominal distention, and vomiting. Abdominal X-ray is the best initial study and usually reveals distended loops of small bowel with multiple air-fluid levels and pneumobilia (air in the biliary tract). Rigler's triad: pneumobilia (air in biliary tree), small bowel obstruction (partial or complete), gallstone (usually in right iliac fossa). ⚠ Acute diverticulitis (choice A) is incorrect. The clinical presentation of diverticulitis depends on the location of the affected diverticulum, the severity of the inflammatory process, and the presence of complications. Left lower quadrant pain is the most common presenting complaint. Plain radiograph films are usually not helpful in acute diverticulitis. In case of bowel perforation, free air may be present, but pneumobilia is not associated with this condition. ⚠ Crohn disease free perforation (choice C) is incorrect. None of the patient’s symptoms is suggestive of Crohn disease. ⚠ Adhesive small bowel obstruction (choice D) would likely occur in a patient with a history of abdominal surgery. This patient never had a surgery. ⚠ Pseudomembranous colitis (choice E) is an antibiotic-associated diarrhea most frequently caused by Clostridium difficile. This patient has no recent history antibiotic use. ✅Key point: Gallstone ileus results from an impaction of a large gallstone in the ileum after being passed through a biliary-enteric fistula. It presents with abdominal distention, abdominal pain, and vomiting. Pneumobilia, air in the biliary tree, can be seen on abdominal X-ray.

🇨🇦 MCCQE1,2 | #Case_63 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 67-year-old female presents with complaints of increasing abdominal distension and intermittent vomiting for the past 4 days. She also reports abdominal pain in the periumbilical region. The pain does not radiate and is not clearly localized. Her past surgical and medical history is significant only for hypertension, which has been well controlled with hydrochlorothiazide. On examination her blood pressure is 120/75 mmHg, temperature is 37.7°C, pulse is 95bpm, and respirations 17/min. She appears in distress, has dry mucosa but no jaundice is observed. Abdominal auscultation reveals gurgling and tinkling sounds. Rectal examination reveals no abnormalities. Abdominal X-ray shows distended loops of small bowel with multiple air-fluid levels and pneumobilia. What is the most likely diagnosis? a) Acute diverticulitis b) Gallstone ileus c) Crohn disease free perforation d) Adhesive small bowel obstruction e) Pseudomembranous colitis

🇨🇦 MCCQE1,2 | #Case_62 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ D 🔎 Explanation Renal biopsy (choice D) is the correct choice. The most likely cause of hematuria in this patient is IgA nephropathy and renal biopsy is necessary to make this diagnosis. IgA nephropathy typically presents in the second or third decade of life with recurrent hematuria during or immediately following upper respiratory infection. Hematuria is the only finding early in the disease. These features together with the fact that IgA nephropathy is one of the most common causes of hematuria put IgA nephropathy as the most likely diagnosis in this patient. ⚠ Measurement of serum anti-streptolysin O titer (choice A) and throat swab culture (choice B) are used to diagnose poststreptococcal glomerulonephritis, which is an unlikely cause of hematuria in this patient. Poststreptococcal glomerulonephritis occurs 1 to 3 weeks following streptococcal pharyngitis in children 2 to 12 years old. Our patient developed hematuria immediately after throat infection and is of older age. ⚠ CT scan of the abdomen (choice C) is not the correct choice. The two causes of hematuria namely renal stones and renal cell carcinoma that can be diagnosed by CT scan of the abdomen are unlikely causes of hematuria in this patient. Although renal stones can present with painless hematuria, their presentation is not related to upper respiratory infections. Also, because most renal stones are radiopaque, they are expected to be seen in the X-ray. Renal cell carcinoma usually occurs in older people between 50 to 70 year old and present with hematuria, abdominal pain, and flank mass. Other presenting symptoms include fever, anemia, and weight loss. Renal cell carcinoma is thus, an unlikely diagnosis in this patient. ⚠ Measurement of serum urea and creatinine (choice E) are nonspecific tests. Any disease that impairs renal function may raise serum urea and creatinine. ✅Key point: Renal biopsy is necessary to make the diagnosis of IgA nephropathy

🇨🇦 MCCQE1,2 | #Case_62 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 25-year-old man presented with red urine. He denied any other urinary symptoms but admitted having sore throat and low grade fever over the last two days. He also admitted to passing red urine at least three times before but it used to clear up in two to three days. Apart from 15 red cells per high power field, urine analysis was otherwise normal. Plain abdominal x-ray was normal. Which of the following investigations would most likely establish the cause of hematuria in this patient? a) Measurement of serum anti-streptolysin O (ASO) titer b) Throat swab culture c) CT scan of the abdomen d) Renal biopsy e) Measurement of blood urea and serum creatinine

🇨🇦 MCCQE1,2 | #Case_61 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ E 🔎 Explanation This patient's electrocardiogram shows tachycardia with wide QRS complexes. The wide QRS indicates that the electrical conduction originated outside of the normal conduction system (ie. the ventricle). Combining this with the absence of a palpable pulse gives the diagnosis of pulseless ventricular tachycardia (VT), which can be divided into three categories: ▪ pulseless ▪ hemodynamically stable (with a pulse) ▪ hemodynamically unstable (with a pulse) (signs of hemodynamic instability include ischemic chest pain, altered mental status, hypotension, tachycardia, tachypnea, and other signs of shock). The management of VT differs for each category (see explanations below and in the incorrect answers). According to ACLS guidelines, pulseless VT is treated the same way as ventricular fibrillation. Two minutes of CPR is started first, followed by unsynchronized cardioversion (defibrillation) (choice E) with 120-200J if using a biphasic defibrillator or 360 J for monophasic defibrillator. If two cycles of CPR and defibrillation fail to eliminate the arrhythmia, then epinephrine can be administered, followed by another cycle of CPR and defibrillation, followed by amiodarone.Pulseless VT is most common in patients who have survived a myocardial infarction, and it can progress to ventricular fibrillation and then death. ⚠ Adenosine (choice A) is not used for pulseless VT. It is used to treat supraventricular tachycardia (SVT). ⚠ Amiodarone (choice B) is an incorrect answer. If the rhythm persists after defibrillation, epinephrine, and a second attempt at defibrillation, then amiodarone 300mg IV can be administered. Amiodarone is also used in hemodynamically stable patients with VT. ⚠ Epinephrine (choice C) can be used in pulseless VT, but only after unsynchronized cardioversion and continued CPR have been attempted. ⚠ Synchronized cardioversion (choice D) is not used in pulseless VT. It can be used in patients with VT who are hemodynamically unstable (hypotension, confusion, shortness of breath) but do have a pulse. ✅ Key point: Pulseless ventricular tachycardia is treated first with CPR, then as soon as possible, unsynchronized cardioversion (defibrillation). If those measures fail, continued cycles of CPR and defibrillation are attempted followed by epinephrine, according to the most recent ACLS guidelines.

🇨🇦 MCCQE1,2 | #Case_61 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 You are called to the bedside of a 56-year-old male patient in the critical care unit. His nurse informs you that he has become unresponsive. He has a history of hypertension, myocardial infarction, and a 30 pack-year history of smoking. A nurse reads his previous vital signs: blood pressure is 90/55 mmHg, his heart rate is 180 bpm, his respiratory rate is 22 breaths per minute, and oxygen saturation is 98% according to the monitor. Looking at the monitor, you notice the patient has wide QRS complexes. On physical exam, you note the patient grunts in response to pain, is currently on a ventilator, and you are unable to palpate his carotid pulse. You decide to start CPR.Which of the following is the next best step in the treatment of this patient? a) Adenosine b) Amiodarone c) Epinephrine d) Synchronized cardioversion e) Unsynchronized cardioversion

🇨🇦 MCCQE1,2 | #Case_60 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ C 🔎 Explanation This patient is having an acute gout attack. Nonsteroidal anti-inflammatory drugs or colchicine (choice C) are first-line therapies for acute gout, depending on patient comorbidities. In general, when comorbid conditions limit the use of NSAIDs or colchicine, a preferred option may be an intra-articular steroid injection (unless contraindicated), particularly when a large, easily accessible joint is involved. ⚠ Ceftriaxone (choice A) is not an appropriate treatment for gout. ⚠ Corticosteroids (choice B) can be given to patients with gout who cannot use NSAIDs or colchicine. Steroids can be given orally, IV, intramuscularly, or intra-articularly. Using parenteral corticosteroids confers no advantage unless the patient cannot take oral medications. ⚠ While indomethacin (choice D) is a good choice for treating an acute gout attack, this patient should not take indomethacin because of the increased risk of bleeding created by warfarin. ⚠ Allopurinol (choice E) should not be used in an acute gout attack as it could make it worse.

🇨🇦 MCCQE1,2 | #Case_60 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 62-year-old female presents to the ED complaining of right leg and knee pain. The pain has progressed over the past 2 weeks so that now she is unable to bear weight on her right leg. She has a history of a recent pulmonary embolus and is on warfarin(Coumadin). Her INR is therapeutic. She is allergic to aspirin and penicillin. On examination she is afebrile. Her pulse rate is 102 beats/min, her blood pressure is 158/96 mmHg, and her respiratory rate is 14/min. Her right knee is erythematous, warm, and tender on palpation over the entire knee joint, and a large effusion is noted. Arthrocentesis reveals numerous WBCs and negatively birefringent crystals.What is the best initial treatment for the patient’s knee problem? a) Ceftriaxone intravenously b) Prednisone intra-articularly c) Colchicine orally d) Indomethacin orally e) Allopurinol orally

🇨🇦 MCCQE1,2 | #Case_59 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ A 🔎 Explanation This patient presents with a clinical picture very suspicious for lung cancer. The patient’s symptoms are cough, hoarseness, lethargy, and weight loss. Physical examination reveals muscle weakness. He is a heavy smoker with 150 packs of cigarettes a year for more than 40 years. Laboratory results show hyponatremia, which in this case should make us think of syndrome of inappropriate antidiuretic hormone (SIADH), a paraneoplastic syndrome associated with oat cell carcinoma (choice A). This cancer is also known as small cell lung carcinoma. ⚠ Sarcoidosis (choice B) is multisystem inflammatory disease of unknown etiology that manifests as noncaseating granulomas, predominantly in the lungs and intrathoracic lymph nodes. It presents with cough in 50% of patients and SIADH is known to affect 5% of sarcoidosis patients, though subclinical and undiagnosed SIADH is much higher. However, this patient’s history of hoarseness, weight loss, age, and long history of heavy smoking seem to point to a diagnosis of oat cell carcinoma. ⚠ Squamous cell lung carcinoma (choice C) is incorrect. The paraneoplastic syndrome commonly seen in squamous cell lung carcinoma is parathyroid-like hormone production, which leads to hypercalcemia. ⚠ Laryngeal squamous carcinoma (choice D) can cause cough, hoarseness, weight loss, and is also associated with cigarette smoking. But lung cancers are far more common than laryngeal cancers, and SIADH is very suggestive of oat cell lung carcinoma. ⚠ Lung adenocarcinoma (choice E) has been recognized as the common type of lung cancer is non-smokers and is not commonly associated with SIADH. ✅Key point: The combination of cough, hoarseness, weight loss, and SIADH in an old patient heavy smoker is suggestive of small cell lung carcinoma also known as oat cell lung carcinoma

🇨🇦 MCCQE1,2 | #Case_59 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 68-year-old male presents to your department because of cough and hoarseness that “just won’t go away”. He has been coughing and had a hoarse voice for 3 weeks now and antitussive OTC medications he has tried have not helped him much. Moreover, the last 3 days he feels that he is getting worse as he felt more lethargic and has been confused at times. He noticed that his shoulder muscles are a bit sore. The patient has lost 8 kg over the last 2 months. He has smoked 150 packs of cigarettes a year the last 42 years.On physical examination only generalized muscle weakness is noted. The patient’s comprehensive metabolic panel reveals: Glucose: 4.1 mmol/l Urea: 7 mmol/ l Creatinine: 100 micromol/L GFR: 70 ml/min/1.73 Sodium: 125 mmol/l Potassium: 3. 9 mmol/l Chloride: 99 mmol/l Calcium: 2. 41 mmol/L Protein total: 61g/l Albumin: 40 g/l Alkaline phosphatase: 60 U/l AST: 35 U/l ALT: 45 U/ l Which of the following is the most likely diagnosis? a) Oat cell lung carcinoma b) Sarcoidosis c) Squamous cell lung carcinoma d) Laryngeal squamous carcinoma e) Lung adenocarcinoma

🇨🇦 MCCQE1,2 | #Case_58 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ B 🔎 Explanation Intrahepatic cholestasis of pregnancy (ICP) classically presents as severe pruritus in the third trimester. Characteristic findings include the absence of primary skin lesions and elevation of serum levels of total bile acids.The most specific and sensitive marker of ICP is total serum bile acid (BA) levels greater than 10 micromol/L. In addition to the elevation in serum BA levels, the cholic acid level is significantly increased and the chenodeoxycholic acid level is mildly increased, leading to elevation in the cholic/chenodeoxycholic acid level ratio. The elevation of aminotransferases associated with ICP varies from a mild increase to a 10- to 25-fold increase.Total bilirubin levels are also increased but usually the values are less than 5 mg/dL. Alkaline phosphatase (AP) is elevated in ICP up to 4-fold, but this is not helpful for diagnosis of the disorder since AP is elevated in pregnancy due to production by the placenta. Mild elevation of gamma glutamyltransferase (GGT) is seen with ICP but occurs in fewer than 30% of cases. However, if GGT is elevated in cases of ICP, that patient is more likely to have a genetic component of the liver disease.