A 52-Year-Old Man Comes to the Emergency Department with Pain

question 65

Multiple Choice

A 52-year-old man comes to the emergency department with pain and swelling of his right knee for the last 24 hours.  He has not traveled recently and has no recent history of injury or gastrointestinal or genitourinary infection.  The patient was diagnosed with pulmonary sarcoidosis 5 years ago when he developed hilar lymphadenopathy and interstitial lung disease.  His sarcoidosis responded to treatment with glucocorticoids and went into remission.  He has been disease-free for the past 4 years.  The patient also has a 10-year history of type 2 diabetes mellitus, hypercholesterolemia, and hypertension.  Blood pressure is 140/86 mm Hg and pulse is 90/min.  BMI is 34 kg/m².  Physical examination is notable for a moderate-size effusion of the right knee with surrounding erythema and warmth.  The knee joint is aspirated.  Microscopic examination of the fluid is shown in the image below. Which of the following is the most likely etiology of this patient's joint effusion?

• A)Immunocomplex deposition
• B)Infection of the joint by fungal organisms
• C)Infection of the joint by Staphylococcus aureus
• D)Inflammatory reaction to calcium pyrophosphate crystals
• E)Inflammatory reaction to monosodium urate crystals

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Definitions:

Constant Rate

A fixed percentage or value that does not change over a specified period of time, often used in financial formulas to calculate growth or decay.

Retained Earnings

The portion of net income not distributed to shareholders but instead reinvested in the business or used to pay off debt.

Common Equity

Represents the stockholders' equity or the amount available to common shareholders as a portion of the net worth of a company.

Capital Structure

The mixture of debt and equity financing that a company uses to fund its operations and growth.