Case-based MCQ

🇨🇦 MCCQE1,2 | #Case_301 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ D 🔎 Explanation Multiple endocrine neoplasia (MEN) has three subtypes, type I, type IIA and type IIB. Type I (Wermer syndrome) involves tumors of the ‘3 P’s -­‐ pituitary (prolactinoma), pancreas and parathyroid (causing elevated PTH levels and hypercalcemia). Type IIA (Sipple syndrome) involves tumors of the parathyroid, adrenal (pheochromocytoma) and thyroid (medullary carcinoma). Type IIB involves tumors of the adrenal, thyroid and mucosal neuromas. Since this patient has been diagnosed with MEN I, he could have surgical removal of any or all of the tumors, which include parathyroidectomy, neurosurgery of the pituitary, removal of a prolactinoma or pancreatic surgery. A thyroidectomy would be considered in MEN IIA and IIB.

🇨🇦 MCCQE1,2 | #Case_301 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 51 year old man presents with symptoms consistent with hypercalcemia, which is confirmed with a high blood calcium measurement. Further imaging results show tumors in three different organs. A diagnoses of Wermer syndrome (MEN I) is made. All of the following surgeries may be indicated in this patient, except: a) Parathyroidectomy b) Neurosurgery of pituitary c) Pancreatic surgery d) Thyroidectomy e) Prolactinoma removal

🇨🇦 MCCQE1,2 | #Case_300 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ D 🔎 Explanation An inguinal hernia usually produces a painless bulge in the groin or scrotum. If the hernia can slide back and forth, the bulge may enlarge when a patient stands or strains. The bulge may get smaller or disappear when the patient lies down. If the hernia is incarcerated, the bulge does not get smaller or disappear. Strangulated hernias usually become very painful within minutes or hours. To diagnose an inguinal hernia, you should examine the groin and the area around it. For the examination, a patient may have to stand and cough or strain. Coughing or straining produces pressure in the abdomen and makes a hernia more obvious. To determine whether the hernia is reducible or incarcerated, you should try to push the loop of intestine back into the abdomen by pushing on the upper part of the scrotum with a gloved finger.

🇨🇦 MCCQE1,2 | #Case_300 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 75 year old man with chronic bronchitis develops a bulge in his left groin. On examination, an elongated swelling is seen above the medial end of the inguinal ligament. When the patient coughs, the swelling enlarges, but does not descend into the scrotum. Which one of the following is the most likely diagnosis? a) Femoral hernia b) Acquired hydrocele c) Inguinal lymphadenopathy d) Inguinal hernia e) Incomplete descent of left testis

🇨🇦 MCCQE1,2 | #Case_299 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ A 🔎 Explanation In a stable patient, when conservative measures fail, intravenous access is necessary. Short term management includes adenosine as the first-­line agent, which is effective in approximately 90% of reentrant narrow-­complex tachycardias (QRS duration, less than 120ms). A defibrillator must be available in the event that new dysrhythmias emerge, particularly postadenosine AF. Procainamide is available for use in resistant cases. In a stable patient, when conservative measures fail, intravenous access is necessary. Short-­term management includes adenosine as the first-­‐line agent, which is effective in approximately 90% of reentrant narrow complex tachycardias (QRS duration, less than 120ms). A defibrillator must be available in the event that new dysrhythmias emerge, particularly postadenosine AF. Procainamide is available for use in resistant cases.

🇨🇦 MCCQE1,2 | #Case_299 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 25 year old male, diagnosed with WPW 2 years ago, presents to the ED complaining of palpitations of 1 hour duration. He denies any major medical illness. He does not smoke but admits to drinking caffeine excessively. His vitals are within normal limits except for a pulse rate of 160/min. The EKG showed a SVT (QRS duration, less than 120 ms) which failed to be controlled by carotid massage. Which of the following is the most appropriate next step in management of this patient? a) Adenosine b) Digoxin c) Diltiazem d) Propranolol e) Verapamil

🇨🇦 MCCQE1,2 | #Case_298 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ E 🔎 Explanation lf this patient's problem was only ischaemic intermittent claudication, then conservative measures including cessation of smoking and encouragement of exercise would be beneficial. However, this man has rest pain and an ankle-brachial index suggestive of critical ischaemia. Active intervention is required if he is not to lose his limb. Certainly his lipid profile must be measured and, it necessary, measures taken such as the use of lipid-lowering agents. His blood sugar levels must be measured. His hypertension needs treatment. The most important observation is that this man warrants an arteriogram and further assessment.

🇨🇦 MCCQE1,2 | #Case_298 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 56-year-old man presents with a six-month history of pain in his right calf. The pain is brought on by walking and was initially eased when he stopped. More recently he has experienced rest pain in the right leg, particularly at night. He smokes 40 cigarettes a day. On examination his BP is 150/100mmHg. His right femoral pulse is diminished and the right dorsalis pedis pulse cannot be felt. His ankle-brachial BP index is 0.3 (normal ratio is 1). Urinalysis is normal. Which one of the following is the most appropriate plan of management? A. Stop smoking, encourage exercise, review in three months. B. Stop smoking, encourage exercise, prescribe pentoxifylline. C. Stop smoking, encourage exercise, prescribe an ACE-inhibitor, D. Arrange duplex Doppler venous studies and review. E. Arrange an arteriogram and review.

🇨🇦 MCCQE1,2 | #Case_297 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ D 🔎 Explanation This 73-year-old female most likely has polymyalgia rheumatica (PMR), suggested by the morning bilateral shoulder pain and stiffness that lasts for more than 45 minutes. PMR is a chronic inflammatory rheumatic disease characterized by muscle pain and stiffness, usually involving the neck, shoulders, and hips. It is sometimes associated with decreased range of motion in the affected joints. Laboratory studies may show abnormal ESR or CRP, and absence of rheumatoid factor. This condition more commonly affects women older than 50 years of age and people of European descent. There are no universally accepted diagnostic criteria. The diagnosis is usually made clinically. However, there are some classification systems that can aid in diagnosis. For instance, the European League Against Rheumatism/American College of Rheumatology 2012 provision classification criteria scoring system below Based on the above system, our patient's score would be 5: she is older than 50 years of age, has bilateral shoulder pain and elevated ESR (required for the PMR diagnosis); she also has morning stiffness > 45 minutes (2 points), limited range of motion in the hip (1 point), and absence of (RF) rheumatoid factor (2 points). The best management option is to treat with Prednisone, 15mg/day (choice A). Oral prednisone in low dose produces a rapid resolution of symptoms. After a period of quiescence, the dose is slowly tapered. Treatment is usually needed for 1-2 years. ⚠Prednisolone, 60mg/day (choice B) is incorrect. High-dose prednisolone would be indicated if she presented with, for instance, giant cell arteritis (GCA) (jaw claudication, temporal headache, or vision loss). However, this patient presented with PMR and low dose corticosteroids should be used to treat it. ⚠ Aspirin 81 mg/day (choice C) is incorrect. Treatment with low-dose aspirin may be associated with fewer cranial ischemic complications in patients with GCA, which can co-exist with PMR; however, this patient has no signs or symptoms consistent with GCA. ⚠ Ibuprofen 200mg every 4 hours as needed (choice D) is incorrect. Nonsteroidal anti-inflammatory drugs are usually not recommended and they are associated with adverse outcomes (drug-related morbidity). ⚠ Prednisone 15mg and ibuprofen (choice E) is an incorrect answer. Treatment with both corticosteroid and nonsteroidal anti-inflammatory drugs is associated with higher rate of adverse effects [level 2(mid-level) evidence]. Based on a retrospective cohort study, at least one adverse event (eg. diabetes, fracture, avascular necrosis, cata racts, upper gastrointestina bleed, hypertension, myopathy ... etc) was observed in patients treated with both corticosteroids and NSAIDs. 🔖Key point: The treatment of polymyalgia rheumatica is low-dose prednisone (15mg/day).

🇨🇦 MCCQE1,2 | #Case_297 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 73-yea r-old Caucasian female presented for evaluation of early morning bilateral shoulder pain and stiffness, lasting one hour, three months aher symptom onset. She also notes fatigue, malaise, and weight loss of 4 pounds during these past three months. Physical examination is as follows: vital signs are stable except for a tem perature of 37.5 °c; musculoskeletal exam of hip and shou lders shows a reduction in the active and passive range of motion; erythrocyte sed imentation rate is 70 mm/h; C-reactive protein and rheumatoid factor are normal. Which of the following is the treatment of choice for this patient's presenting condition? a. Prednisone, 15mg/day b. Prednisolone, 60mg/day c. Aspirin, 81 mg/day d. Ibuprofen, 200mg every 4 hours as needed e. Prednisone, 15mg and Ibuprofen

🇨🇦 MCCQE1,2 | #Case_296 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ D 🔎 Explanation Based on the patient's history of glucose intolerance, hyperpigmentation of skin, arthropathy, and family history of heart disease, hereditary hemochromatosis which is known to cause "bronze diabetes" should be considered as the likely diagnosis. Hemochromatosis is an autosomal recessive genetic disorder characterized by iron overload and accumulation in parenchymal organs. While as many as 75% of patients are asymptomatic, those with symptoms often present with skin bronzing, diabetes mellitus, cardiomyopathy, liver disease, and inferti lity. Transferrin saturation which is the ratio of serum iron and total iron-binding capacity suggests the diagnosis. It may be confirmed by liver biopsy and genotypic investigation for HFE mutations on chromosome 6. Management of this condition consists of removal of accumulated iron via phlebotomy (choice D) or, rarely, iron chelation and reducing iron absorption by dietary limitations. Phlebotomy continues for life based on ferritin levels. Ibuprofen (choice A) is a NSAID that may be used to treat osteoarthritis and other arthropathies. It is important to acknowledge that arthropathy in this patient is due to iron overload and management should focus on the cause. ⚠️ ACTH inhibitors such as pasireotide (choice B) are approved for treating Cushing's syndrome. While Cushing syndrome increases the risks of insulin resistance and developing diabetes and is associated with hyperpigmentation, this patient's family history and arthropathy suggest hereditary hemochromatosis ⚠️ ACTH inhibitors such as pasireotide (choice B) are approved for treating Cushing's syndrome. While Cushing syndrome increases t he risks of insulin resistance and developing diabetes and is associated with hyperpigmentation, this patient's family history and arthropathy suggest hereditary hemochromatosis. ⚠️ Colchicine (choice C) may be used in hemochromatosis patients who have had recurrent acute episodes of joint involvement; however, this is not the initial treatment once hemochromatosis is confirmed. Phlebotomy should be done first to decrease iron stores. ⚠️ Metyrapone (choice E) blocks 11-beta-hydroxylase activity, the final step in cortisol synthesis and is used in the treatment of Cushing's syndrome, it is not appropriate as initial management of this patient. 🔖 Key point: Hereditary hemochromatosis is characterized by iron overload and deposition of iron in different organs of the body. This may result in diabetes due to pancreatic islet cell failure, liver disease, dilated cardiomyopathy, and arthropathy. The initial treatment is phlebotomy.

🇨🇦 MCCQE1,2 | #Case_296 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 42-year-old male presents with complaints of painful wrist joints and knee joints. He says that he began to feel discomfort 2 months ago but it has gotten progressively worse in the past week. He also says that he noticed he looks like someone who has been "sun tanning" although he is an office worker and spends most of the time indoors. His past medical history is only significant for glucose intolerance found 1 year ago that he has been managing with lifestyle modifications; however as he puts it "the joint pai ns are making it hard for him to exercise." Family history reveals a father who died of heart disease at the age of 57 and had a long history of diabetes. The patient has a 65-year old mother who is healthy. Physical examination reveals hyperpigmentation of skin and pain on palpation of the proximal interphalangeal joints, wrist joints and knee joints. Imaging studies and laboratory studies are ordered. Which of the following is the most important step in management of this patient? a. Ibuprofen b. ACTH inhibitors c. Colchicine d. Phlebotomy e. Metyrapone

🇨🇦 MCCQE1,2 | #Case_295 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ A 🔎 Explanation This patient's goal LDL-cholesterol level is less than 2 mmoi/L, and he is not at the maximum dosage (40mg/day) of a potent statin. There is no data that shows that adding a different statin wil l be beneficial, and outcomes data for the other actions is lacking. For patients not at their goal LDL cholesterol level, the maximum dosage of a statin should be reached before alternative therapy is chosen

🇨🇦 MCCQE1,2 | #Case_295 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 52-year-old hypertensive male has had two previous myocardial infarctions. In spite of his best efforts, he has not achieved significant weight loss and he finds it difficult to follow a heart-healthy diet. He takes rosuvastatin, 20 mg/day, and his last lipid profile showed a total cholesterol level of 5.65 mmoi/L, a triglyceride level of 2.15 mmoi/L, an HDL-cholesterol level of 1.1 mmoi/L, and an LDL-cholesterollevel of 2.5 mmoi/L. Which one of the following would be the most appropriate change in management? a) Increase the rosuvastatin dosage b) Add atorvastatin c) Add niacin d) Add fenofibrate e) Add ezetimibe

🇨🇦 MCCQE1,2 | #Case_294 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ E 🔎 Explanation The condition of this patient with a history of scleroderma is deteriorating and she is presenting with interstitial lung disease and pulmonary hypertension. These complications are seen in 15% of patients with scleroderma. Chest auscultation findings of bilateral basal crepitations suggest interstitial lung disease (also cal led pulmonary fibrosis) and the increased pulmonic second heart sound (P2) suggests pulmonary hypertension. Chest X-ray may be used for initial imaging studies but it is an insensitive imaging procedure that shows only late findings of pulmonary fibrosis such as increased interstitial markings. HRCT scan is required to evaluate pulmonary involvement. Imaging may reveal a ground glass appearance possibly indicating active alveolitis. Ground glass appearance on HRCT scan is the first abnormality observed during the development of lung fibrosis and is subsequently replaced by honeycombing and traction bronchiectasis or brochiolectasis. Right heart catheterization remains the standard criterion for diagnosing pulmonary hypertension and is performed after an elevated pulmonary artery pressure is found on transthoracic echocardiography. Pulmonary function testing is done to evaluate DLCO (Carbon monoxide diffusion capacity), FVC (forced vital capacity), and TLC (total lung capacity), it is a very sensitive technique for detecting early fibrotic changes, alveolitis, and pulmonary hypertension. Pulmonary function tests will show decreased forced vital capacity, TLC, and a low DLCO. These changes reflect fibrotic infiltration in the lung. An isolated or disproportionate reduction of DLCO with a ratio of forced vital capacity (FVC) or total lung capacity (TLC) to DLCO of greater than 1.6 indicates pulmonary vascular fibrosis and vascular obliteration that leads to pulmonary hypertension. ⚠️ In scleroderma induced pulmonary hypertension DLCO is low and PCWP < 15 mmHg. ⚠️ Though DLCO is low and PCWP < 15 mmHg, the TLC/DLCO ration is greater than 1.6 in pulmonary hypertension. ⚠️ DLCO is low in pulmonary fibrosis with pulmonary hypertension. ⚠️ DLCO is low. 🔖 Key point: Pulmonary scleroderma; DLCO is decreased and TLC/DLCO >1.6

🇨🇦 MCCQE1,2 | #Case_294 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 39-year-old African-American female with a 5-year-history of scleroderma presents with complaints of fatigue, severe heartburn, progressive dyspnea, and persistent dry cough. She has been using antacids for her esophageal symptoms. Head and neck examination shows retractions of the soft tissues around her mouth. Chest auscultation reveals bilateral basal crepitations. There is an accentuated pulmonic second heart sound on cardiac examination. Chest X-ray shows symmetric, basal, reticulonodular shadowing. Which of the following findings would be most likely present in this patient? (I - increased, D - decreased) a) DLCO [I]; PCWP [D); TLC/DLCO > 1 .6 b) DLCO [D]; PCWP [I]; TLC/DLCO < 1 .6 c) DLCO [I]; PCWP normal; TLC/DLCO < 1 .6 d) DLCO [I]; PCWP [I]; TLC/DLCO < 1.6 e) DLCO [D]; PCWP normal; TLC/DLCO > 1.6

🇨🇦 MCCQE1,2 | #Case_293 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ E 🔎 Explanation In iron deficiency anemia, total-body iron levels are low. leading to hypochromia and microcytosis, low iron levels. increased transferrin levels. and reduced ferritin levels. This patient's anemia is most likely multifactorial, with anemia of chronic disease and drug effects playing a role. However. she also has iron deficiency, and oral ferrous sulphate treatment should be initiated with regular testing to monitor treatment response. ⚠️ In males and in postmenopausal women, a Gl work-up (choice A) is always warranted. ⚠️ With thalassemia (choice B), marked microcytosis is seen, and with hemolysis of any standing, slight macrocytosis and an increased reticulocyte count would be expected. ⚠️ Methotrexate has rarely caused serious side effects. In high doses. it may cause some Gl bleeding when used at the same time as non steroidal anti-inflammatory drugs. In this case. it would present with blood in stool or urine. This patient's findings are negative for blood in stool. Stopping the methotrexate and beginning an alternative treatment for rheumatoid arthritis (choice C) would be unnecessary until evaluation for a blood loss source is identified. ⚠️ No further evaluation (choice D) is incorrect. This patient's anemia requires further evaluation.

🇨🇦 MCCQE1,2 | #Case_293 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 45-year-old female with rheumatoid arthritis has a hemoglobin level of 95 giL. Her arthritis is well controlled with methotrexate (Trexall). Further evaluation reveals the following: Hematocrit: 29.0% Mean corpuscular volume: 78 fl Platelets: 230 x 10^9/L WBC: 6.9 X 10^9/l Differential: normal Serum iron: 6 micromol/L Total iron binding capacity: 150 micromol/L Iron saturation: 10% Serum ferritin: 7 microgram/L Reticulocyte count: 8x10^9/L Stool guaiac: negative x 3 Which one of the following would be the most appropriate next step? a) Evaluation for a source of blood loss b) Hemoglobin electrophoresis to screen for thalassemia c) Stopping the methotrexate and beginning an alternative treatment for rheumatoid arthritis d) No further evaluation at this point e) Initiate iron supplement pills

🇨🇦 MCCQE1,2 | #Case_292 | #answer 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 ✅ C 🔎 Explanation Maintaining good blood glucose control is important for preventing the microvascular complications of diabetes mellitus. A number of oral antihyperglycemic agents are available, but each drug class has unique adverse effects that affect their appropriateness for individual patients. In this case, the patient has evidence of renal impairment (serum creatinine 1 .5 mg/dl for men and 1 .4 mg/dl for women). This leads to an increased risk of lactic acidosis when a biguanide such as metformin is used. Other contraindications to biguanide use include hepatic dysfunction, congestive heart failure, metabolic acidosis, dehydration, and alcoholism. The sulfonylureas include chlorpropamide (1st generation) and glipizide (2nd generation). They are associated with weight gain and hypoglycemia. a-Glucosidase inhibitors (e.g., acarbose) are less effective than other drug classes as monotherapy and can be associated with gastrointestinal side effects. Thiazolidinediones (e.g., pioglitazone) are associated with weight gain, edema, and potential liver injury

🇨🇦 MCCQE1,2 | #Case_292 〰〰〰〰〰〰〰〰〰〰〰〰〰〰 A 45-year-old male was recently diagnosed with type 2 diabetes mellitus. He presents to your office today to begin oral antihyperglycemic therapy. Results of a fasting serum metabolic panel include the following: Laboratory Findings: Sodium: 136 mmoi/L (N 136-145) Potassium: 3.7 mmoi/L (N 3.5-5.1) Chloride: 102 mmoi/L (N 98-1 07) BUN: 15 mg/dL (N 7-18) Creatinine: 1.7 mg/dL (N 0.6-1.3) Glucose: 183 mg/dL Which one of tile following medications would be contraindicated in this patient? a) Glipizide (Giucotrol) b) Acarbose(Precose) c) Metformin (Giucophage) d) Pioglitazone (Actos)