🇨🇦 MCCQE1,2 | #Case_228 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ A

🔎 Explanation

Cellulitis in patients after breast lumpectomy is thought to be related to lymphedema. Axillary dissection and radiation predispose to these infections. Non-group A hemolytic Streptococcus is the most common organism associated with this infection. The onset is often several weeks to several months after surgery. Pneumococcus is more frequently a cause of periorbital cellulitis. It is also seen in patients who have bacteremia with immunocompromised status. Immunocompromising conditions would include diabetes mellitus, alcoholism, lupus, nephritic syndrome, and some hematologic cancers.
Clostridium and Escherichia coli are most frequently associated with crepitant cellulitis and tissue necrosis. Pasteurella multocida cellulitis is most frequently associated with animal bites, especially cat bites.

🇨🇦 MCCQE1,2 | #Case_229
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

At 32 weeks’ estimated gestational age, a 26-year-old multipara has been hospitalized for 10 days for premature rupture of membranes (PROM). She had a previous LTCS (Low Transverse Cesarean Section) because of arrested dilation. For 2 hours she has had light vaginal bleeding and contractions every 15 minutes. Over the past 30 minutes the bleeding has increased slightly, and she experiences lower abdominal pain between contractions. Her temperature is 37.0°C (98.6°F). The uterus is tender and the fetal heart rate is 170 bpm. Platelet count is 130x109/L, leukocyte count is 14.3x109/L, serum fibrinogen is 225 mg/dl, and the assay for fibrin split products is positive. Which of the following is the most likely diagnosis?

a) Complete placenta previa
b) Chorioamnionitis
c) Abruptio placentae
d) Uterine scar dehiscence
e) HELLP syndrome

🇨🇦 MCCQE1,2 | #Case_229 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ C

🔎 Explanation

Although this patient has had a prior cesarean section, the possibility of a uterine scar separation is low. With the
presence of ruptured membranes (ROM), a complete previa is unlikely. Although the uterus is tender, the patient is afebrile. There is literature to suggest that prolonged preterm ROM is associated with an increased risk of abruptio placentae.

⚠ Ruptured membranes with a complete previa is very unlikely.

⚠ Chorioamnionitis can be a complication of prolonged preterm rupture of membranes. It can be associated with contractions and uterine pain, but is usually not associated with vaginal bleeding.

⚠ Uterine scar separation can occur with a prior cesarean, but usually occurs in active labor. This patient is showing
signs of early uterine activity at 32 weeks’ gestation, making this diagnosis unlikely.

⚠ HELLP syndrome is hemolysis, elevated liver enzymes, and low platelets

🇨🇦 MCCQE1,2 | #Case_230
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 43-year-old male complains of difficulty washing his face and combing his hair with his right hand. On examination a nodule, band, and slight contracture are noted in the palm proximal to the fourth finger. This patient’s condition is associated with which one of the following?

a) Hyperparathyroidism
b) Diabetes mellitus
c) Hyperthyroidism
d) Hypothyroidism
e) Adrenal insufficiency

🇨🇦 MCCQE1,2 | #Case_230 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ B

🔎 Explanation

The patient has Dupuytren’s contracture, which is most common in men over 40 years of age. It is a progressive condition that causes the fibrous fascia of the palmar surface to shorten and thicken. It initially can be managed with observation, but corticosteroid injection and surgery may be needed. The condition will regress in 10% of patients. There is a 3%-33% prevalence of Dupuytren’s contracture in patients with diabetes mellitus; however, these patients tend to have a mild form of the disease with slow progression.; however, these patients tend to have a mild form of the disease with slow progression.

🇨🇦 MCCQE1,2 | #Case_231
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 44-year-old black female reports diffuse aching, especially in her upper legs and shoulders. The aching has increased, and she now has trouble going up and down stairs because of weakness. She has no visual symptoms, and a neurologic examination is normal except for proximal muscle weakness. Laboratory tests reveal elevated levels of serum creatine kinase and aldolase. Her symptoms improve significantly when she is treated with corticosteroids. Which one of the following is the most likely diagnosis?

a) Duchenne’s muscular dystrophy
b) Myasthenia gravis
c) Amyotrophic lateral sclerosis
d) Aseptic necrosis of the femoral head
e) Polymyositis

🇨🇦 MCCQE1,2 | #Case_231 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ E

🔎 Explanation

The patient described has an inflammatory myopathy of the polymyositis/dermatomyositis (choice E) group. Proximal muscle involvement and elevation of serum muscle enzymes such as creatine kinase and aldolase are characteristic. Corticosteroids are the accepted treatment of choice.

⚠ It is extremely unlikely that Duchenne’s muscular dystrophy (choice A) would present after age 30.

⚠ Patients with myasthenia gravis (choice B) characteristically have ocular involvement, often presenting as ptosis and/or diplopia.

⚠ In amyotrophic lateral sclerosis (choice C) an abnormal neurologic examination with findings of upper or lower motor neuron dysfunction is characteristic.

⚠ The predominant symptom of aseptic necrosis (choice D) of the femoral head is pain rather than proximal muscle weakness. Elevated muscle enzymes are not characteristic

🇨🇦 MCCQE1,2 | #Case_232
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 67-year-old male presents with complaint of anginal chest discomfort that comes and goes. He states it always happens when he is lying in his bed or watching TV lying on his couch and is unrelated to his exercise. Identify the type of angina patient is experiencing:

a) Prinzmetal’s angina
b) Unstable angina
c) Stable angina
d) Angina decubitus
e) Variant angina

🇨🇦 MCCQE1,2 | #Case_232 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ D

🔎 Explanation

Angina decubitus (choice D) is the correct answer. It is angina that occurs when a person is lying down (not necessarily only at night) without any apparent cause. Angina decubitus occurs because gravity redistributes fluids in the body. This redistribution makes the heart work harder.

⚠ Prinzmetal’s angina (choice A) is induced by coronary artery spasm which is reflected by either permanent blockade or blockade due to plaque. This usually occurs at rest. Its occurrence is increased in people who smoke, it may occur when patients are sitting or standing, this is not the case for angina decubitus.

⚠ Unstable angina (choice B) occurs at rest in patients with significant coronary artery disease. Angina occurs frequently for extended periods of more than 20 minutes with a week’s presence.

⚠ Stable angina (choice C) occurs due to exertion or stress. This type of angina is relieved by rest or by nitrates.

⚠ Variant angina (choice E) is just another name for Prinzmetal’s angina

🇨🇦 MCCQE1,2 | #Case_233
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 70-year-old white female complains of two episodes of urinary incontinence. On both occasions she was unable to reach a bathroom in time to prevent loss of urine. The first episode occurred when she was in her car and the second while she was in a shopping mall. She is reluctant to go out because of this problem.The most likely cause of her problem is:

a) Overflow incontinence
b) Stress incontinence
c) Urge incontinence
d) Functional incontinence

🇨🇦 MCCQE1,2 | #Case_233 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ C

🔎 Explanation

At least one million Canadians suffer from urinary incontinence. In the neurologically intact individual the most common subtypes are stress incontinence, which occurs with coughing or lifting; urge incontinence, which occurs when patients sense the urge to void but are unable to inhibit leakage long enough to reach the toilet; and overflow incontinence, which
occurs when the bladder cannot empty normally and becomes overdistended. The term functional incontinence is applied to those cases where lower urinary tract function is intact but other factors such as immobility and severe cognitive impairment lead to incontinence. This patient has mild urge incontinence. The first approach to this problem should be behavioral. In a mild case such as this, a cure can be expected, with success rates of 30%-90% in published studies. For more severe cases, various pharmacologic agents, including anticholinergics, are useful. Failure of these modalities should lead to urodynamic testing and consideration of surgery

🇨🇦 MCCQE1,2 | #Case_234
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 69-year-old male presents to the emergency department with complaints of suddenly increased shortness of breath. He was diagnosed with COPD 10 years ago. His medications are tiotropium, formoterol, and albuterol. Usually when he is short of breath he uses albuterol, which alleviates the symptoms. However, "it has not helped much this time." He has smoked 40 packs of cigarettes a year for the last 45 years. On physical examination he has hyperresonance to percussion and decreased breath sounds on auscultation at the right side. His oxygen saturation is 87%. Which of the following is the most appropriate next step in management?

a) Albuterol inhaler, ipratropium, and oral prednisone
b) Sputum cultures and initiation of azithromycin
c) Order chest radiograph
d) Intubation and mechanical ventilation with 100% oxygen
e) Oxygen administration at 3L/min nasal cannula

🇨🇦 MCCQE1,2 | #Case_234 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ E

🔎 Explanation

This patient’s history of smoking and COPD, the presentation with shortness of breath, decreased breath sounds on the right, and hyperresonance to percussion point to a diagnosis of spontaneous pneumothorax. COPD is the most common cause of secondary spontaneous pneumothorax accounting for 60% of cases on average. Rupture of apical blebs is the usual cause. Out of the choices given, oxygen administration at 3L/min nasal cannula (choice E) is the most appropriate initial step in management of this patient. Oxygen treats hypoxemia and is associated with a 4-fold increase in the rate of pleural air absorption compared with room air alone. If the patient doesn't respond to oxygen supplementation, chest tube placement would be the most appropriate next-in-line treatment.

⚠ Albuterol inhaler, ipratropium, and oral prednisone (choice A) would be appropriate for the management of COPD exacerbation.

⚠ Sputum cultures and initiation of azithromycin (choice B) would be appropriate if community acquired pneumonia is suspected. This patient’s clinical scenario suggests spontaneous pneumothorax.

⚠ Order chest radiograph (choice C) should be part of the management plan of this patient’s condition, but oxygen should be given prior to investigations.

⚠ Intubation and mechanical ventilation with 100% oxygen (choice D) is incorrect. The appropriate initial oxygen supplementation should be done by nasal cannula.

🔖 Key point:

Sudden increase of shortness of breath, unilateral decreased breath sounds on auscultation and hyperresonance to
percussion in a patient with COPD history is suggestive of spontaneous pneumothorax. Oxygen supplementation (through a nasal cannula) is an appropriate initial treatment of spontaneous pneumothorax.

🇨🇦 MCCQE1,2 | #Case_235
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 28-year-old female complains of generalized headache, dizziness (characterized as lightheadedness), and generally not feeling well for 3 days. This started at the same time as her menses and coincided with a major examination in a college class she is taking. Her review of symptoms is otherwise negative. Her past medical history includes a recent acute onset of low back pain related to lifting, and a recent depressive episode which responded well to medication. Her current medications include an oral contraceptive which she has taken for 2 years, a corticosteroid nasal spray, and ibuprofen for the past 2 weeks. She was on paroxetine (Paxil), 30 mg/day, for 7 months, but this was stopped 5 days ago because of sexual dysfunction. Because of her symptoms she has not taken any medications for the past 2 days. Since then the headache has eased substantially, but the feeling of lightheadedness has remained. A physical examination is unremarkable. Which one of the following is the most likely cause of her symptoms?

a) Allergic rhinitis
b) Paroxetine withdrawal
c) Serotonin syndrome
d) Viral infection
e) Stress

🇨🇦 MCCQE1,2 | #Case_235 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ B

🔎 Explanation

The timing of the symptoms (starting about 2 days after paroxetine was stopped) and the symptoms (headache, light headedness) are consistent with SSRI discontinuation syndrome. This syndrome is more likely with abrupt withdrawal, after prolonged treatment, at higher doses.

🇨🇦 MCCQE1,2 | #Case_236
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 2-year-old toddler is brought to the emergency department eight hours after accidental ingestion of gasoline. On examination she is afebrile and has no respiratory distress. Chest x-ray is normal. Which one of the following is the most appropriate intervention?

a) Oral corticosteroid treatment
b) Antibiotic to prevent pneumonitis
c) Induce vomiting to empty the stomach
d) Admit to ward for observation only
e) Discharge home, but to return if tachypneic

🇨🇦 MCCQE1,2 | #Case_236 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ E

🔎 Explanation

There is no antidote for gasoline poisoning. Treatment consists of support of cardiovascular and respiratory functions. In cases of ingestion, do not induce emesis or use gastric lavage and do not administer activated charcoal. Gasoline is poorly absorbed from the stomach. Catharsis with magnesium or sodium sulfate is acceptable. If spontaneous vomiting occurs, watch for signs of pulmonary aspiration. All symptomatic patients should have a chest X-ray taken no sooner than two hours post ingestion, and should be observed in the emergency department for a period of six hours. The patient may be discharged with observation at home if asymptomatic throughout and X-ray is negative, as in this patient. In the presence of a positive two-hour X-ray, the patient should be admitted for monitoring of blood gases, repeat chest X-rays, and respiratory support if required. This child has no respiratory distress and Chest X-ray did not show any abnormalities, therefore, he should be discharged home (choice E).

⚠ Steroids (choice A) and Antibiotic prophylaxis (choice B) are of no proven benefit in gasoline and other hydrocarbon poisoning.

⚠ Induce vomiting to empty the stomach (choice C) is incorrect. Gasoline is poorly absorbed from the stomach and emesis should not be induced. Decontamination should focus on removing any remaining hydrocarbon that might be on the clothes or skin, in the correct clinical setting.

⚠ Admit to ward for observation (choice D) is unnecessary for a patient whose condition is consiered stable in the emergency room

🇨🇦 MCCQE1,2 | #Case_237
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 75-year-old female is admitted to the hospital with a change in mental status. The initial workup includes a chemistry profile that reveals a plasma potassium level of 6.4 mEq/L (N 3.7-5.2). Which one of the following should be given now to rapidly lower the plasma potassium level?

a) Corticosteroids
b) Albuterol
c) Sodium polystyrene sulfonate
d) 0.45% saline
e) Acute hemodialysis

🇨🇦 MCCQE1,2 | #Case_237 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ B

🔎 Explanation

Severe hyperkalemia (> 6.0 mEq/L) requires aggressive treatment. Calcium gluconate has no effect on the plasma
potassium level, but it should be given first, as it rapidly stabilizes the membranes of cardiac myocytes, reducing the risk of cardiac dysrhythmias. Therapies that translocate potassium from the serum to the intracellular space should be instituted next, as they can
quickly (albeit temporarily) lower the plasma concentration of potassium. These interventions include sodium bicarbonate, glucose with insulin, and albuterol. Total body potassium can be lowered with sodium polystyrene sulfonate, but this takes longer to affect the plasma potassium level than translocation methods. In the most severe cases, acute hemodialysis can be instituted

🇨🇦 MCCQE1,2 | #Case_238
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

A 58-year-old male who works with heavy machinery at a local factory presents to your office for evaluation of hearing loss of several years’ progression. He notes that the loss is mainly in the left ear and he also has mild tinnitus. He has had no trauma to his head and he has no history of ear infections. Examination of the ears reveals normal tympanic membranes and a neurologic examination is negative. When a tuning fork is placed in the center of his forehead, he says the sound is much louder on the right side (Weber test). Comparing sound in front of the ear to the sound when the tuning fork is placed on the mastoid (the Rinne test) reveals that air conduction is better than bone conduction in the left ear. Which one of the following is true regarding further evaluation and management?

a) No treatment or further diagnostic studies are indicated
b) A hearing aid plus better hearing protection is all that is needed
c) Carotid ultrasonography should be ordered
d) A tympanogram is indicated
e) Audiometry is the best initial screening test

🇨🇦 MCCQE1,2 | #Case_238 | #answer
〰〰〰〰〰〰〰〰〰〰〰〰〰〰

✅ E

🔎 Explanation

Acoustic neuroma symptoms are due to cranial nerve involvement and progression of tumor size. Hearing loss is present 95% of the time and tinnitus is very common. The loss is usually chronic (over 3 years) and as many as one-third of patients are unaware it has occurred. Vestibular nerve involvement most often causes mild unsteadiness and rarely has accompanying true vertigo. Trigeminal involvement can cause pain, paresthesias, or numbness of the face. Facial paralysis occurs 6% of the time. The diagnosis of acoustic neuroma is based on asymmetric sensorineural hearing loss or another cranial nerve deficit, with confirmation based on MRI with gadolinium contrast or a CT scan. The best initial screening laboratory test is audiometry, as only 5% of patients with acoustic neuroma will have a normal test. Sensorineural loss is usually in the higher frequencies. Brainstem-evoked response audiometry may be used as a further screening measure when there are unexplained symmetrics and standard audiometric testing