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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{AO}}
|QuestionAuthor={{AO}}  
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Pathology
|MainCategory=Pathology
Line 20: Line 20:
|MainCategory=Pathology
|MainCategory=Pathology
|SubCategory=Renal
|SubCategory=Renal
|Prompt=A 5-year-old boy is brought to the emergency department by his mother because she noticed that his eyes appear swollen when he wakes up in the morning for the past 4 days.  The eye swelling tends to resolve over the course of the day. The mother told you that he was stung by a bee two weeks ago, and there was also an outbreak of influenza in his school some few weeks back.  He is generally very healthy and there is no family history of any chronic disease. His temperature is 36.7 C (98.0 F), blood pressure is 140/90 mm Hg, pulse is 92/min, and respiratory rate is 17/min. Physical examination is unremarkable.  Urinalysis shows oval fat bodies and profound proteinuria.  Which of the following findings is needed to make a diagnosis on light microscopy?
|Prompt=A 5-year-old boy is brought to the emergency room by his mother because she notices that his eyes have appeared swollen when he wakes up in the morning for the past 4 days.  The eye swelling tends to resolve over the course of the day. The mother tells you that he was stung by a bee two weeks ago, and that there was also an outbreak of influenza in his school some few weeks back.  He is generally very healthy and there is no family history of any chronic disease. Upon examination, the temperature is 36.7°C, the blood pressure 140/90 mm Hg, the pulse 92 beats per minute, and the respiratory rate 17 breaths per minute. Physical examination is normal.  Urinalysis shows oval fat bodies and profound proteinuria.  Which of the following microscopy findings is required in order to establish a diagnosis?
|Explanation=The boy in this vignette has [[nephrotic syndrome]].  This is a kidney disorder characterized by [[proteinuria]], [[hypoalbuminemia]] and [[edema]].  Minimal change disease a.k.a Nil disease or lipoid nephrosis is the commonest cause of nephrotic syndrome in very young children.  It usually starts with facial edema.  It can be triggered by a bee sting, previous upper respiratory tract infections, drugs or malignancies.  Treatment is very effective with corticosteroids.
|Explanation=The boy in this scenario has [[nephrotic syndrome]], characterized by [[proteinuria]], [[hypoalbuminemia]], and [[edema]].  Minimal change disease, also referred to as lipoid nephrosis, is the most common cause of nephrotic syndrome in very young children.  It usually starts with facial edema and can be triggered by a bee sting, previous upper respiratory tract infections, drugs, or malignancies.  Treatment is very effective with corticosteroids.


Educational Objective: Nephrotic syndrome is characterized by [[proteinuria]], [[hypoalbuminemia]] and [[edema]].  Minimal change disease is the commonest cause of NS in children, and it can be effectively treated with steroids.  
Educational Objective: Nephrotic syndrome (NS) is characterized by [[proteinuria]], [[hypoalbuminemia]] and [[edema]].  Minimal change disease is the commonest cause of NS in children, and it can be effectively treated with steroids.  
|AnswerA=Segmental sclerosis and hyalinosis
|AnswerA=Segmental sclerosis and hyalinosis
|AnswerAExp=Incorrect.  This is a characteristic finding in focal segmental glomerulosclerosis.  This is the commonest glomerular disease in [[HIV]] patients, heroin addicts, and [[sickle cell disease]].  It is also the commonest cause of nephrotic syndrome in adult.
|AnswerAExp=Incorrect.  These are characteristics dislayed in [[focal segmental glomerulosclerosis]].  This is the most common glomerular disease amoung patients with [[HIV]] or[[sickle cell disease]].  It is also the most common cause of nephrotic syndrome in adults.
|AnswerB=Diffuse capillary and glomerular basement membrane thickening
|AnswerB=Diffuse capillary and glomerular basement membrane thickening
|AnswerBExp=Incorrect.  This is a finding observed in membranous glomerulonephritis (diffuse membranous glomerulonephropathy).  This is a slowly progressive disease of the kidney affecting mostly patients between ages of 30 and 50 years, usually Caucasians.
|AnswerBExp=Incorrect.  This is a finding observed in membranous glomerulonephritis ([[diffuse membranous glomerulonephropathy]]).  This is a slowly progressive kidney disease prevalent amoung Caucasians between 30 and 50 years of age.
|AnswerC=Normal glomeruli
|AnswerC=Normal glomeruli
|AnswerCExp=Correct.  The glomeruli in minimal change disease are normal or near normal when examined using a light microscope.  Electron microscopy reveals flattening and fusion of the podocyte foot processes in the glomeruli.
|AnswerCExp=Correct.  The glomeruli in minimal change disease are normal or near normal when examined using a light microscope.  Electron microscopy demonstrates flattening and fusion of the [[podocyte]] foot processes in the glomeruli.
|AnswerD=Enlarged, hypercellular glomeruli with a “lumpy-bumpy” appearance
|AnswerD=Enlarged, hypercellular glomeruli with proliferation of mesangial and endothelial cells
|AnswerDExp=Incorrect.  Enlarged, hypercellular glomeruli with a “lumpy-bumpy” appearance on light microscope refer to an acute post-streptococcal glomerulonephritis.  Electron microscopy reveals sub epithelial immune complexes.  It may present with dark urine, periorbital edema. Acute glomerulonephritis is characterized by the sudden appearance of hematuria, proteinuria, red blood cell casts in the urine, edema, and hypertension with or without oliguria. It can follow streptococcal infections.
|AnswerDExp=Incorrect.  Enlarged, hypercellular glomeruli with proliferation of mesangial and endothelial cells using a light microscope are indicative of acute [[PSGN|post-streptococcal glomerulonephritis]].  Electron microscopy demonstrates sub-epithelial [[immune complex]]es and a "lumpy-bumpy" appearance.  It may present with dark urine, hypertension, and periorbital edema with or without oliguria. Acute [[glomerulonephritis]] is characterized by the onset of [[hematuria]], [[proteinuria]], and red blood cell casts in the urine.
|AnswerE=“Wire looping” of capillaries
|AnswerE=“Wire looping” of capillaries
|AnswerEExp=Incorrect.  This is a feature seen in diffuse proliferative glomerulonephrits.  This is mostly caused by SLE.
|AnswerEExp=Incorrect.  “Wire looping” of capillaries is a feature indicative of diffuse proliferative [[glomerulonephrits]], frequently observed amoung patients with [[systemic lupus erythematosus|systemic lupus erythematosus (SLE)]].
|RightAnswer=C
|RightAnswer=C
|WBRKeyword=Nephrotic syndrome, minimal change disease
|WBRKeyword=Nephrotic syndrome, minimal change disease
|Approved=Yes
|Approved=Yes
}}
}}

Revision as of 17:48, 1 July 2014

 
Author [[PageAuthor::Ayokunle Olubaniyi, M.B,B.S [1]]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pathology
Sub Category SubCategory::Renal
Prompt [[Prompt::A 5-year-old boy is brought to the emergency room by his mother because she notices that his eyes have appeared swollen when he wakes up in the morning for the past 4 days. The eye swelling tends to resolve over the course of the day. The mother tells you that he was stung by a bee two weeks ago, and that there was also an outbreak of influenza in his school some few weeks back. He is generally very healthy and there is no family history of any chronic disease. Upon examination, the temperature is 36.7°C, the blood pressure 140/90 mm Hg, the pulse 92 beats per minute, and the respiratory rate 17 breaths per minute. Physical examination is normal. Urinalysis shows oval fat bodies and profound proteinuria. Which of the following microscopy findings is required in order to establish a diagnosis?]]
Answer A AnswerA::Segmental sclerosis and hyalinosis
Answer A Explanation [[AnswerAExp::Incorrect. These are characteristics dislayed in focal segmental glomerulosclerosis. This is the most common glomerular disease amoung patients with HIV orsickle cell disease. It is also the most common cause of nephrotic syndrome in adults.]]
Answer B AnswerB::Diffuse capillary and glomerular basement membrane thickening
Answer B Explanation [[AnswerBExp::Incorrect. This is a finding observed in membranous glomerulonephritis (diffuse membranous glomerulonephropathy). This is a slowly progressive kidney disease prevalent amoung Caucasians between 30 and 50 years of age.]]
Answer C AnswerC::Normal glomeruli
Answer C Explanation [[AnswerCExp::Correct. The glomeruli in minimal change disease are normal or near normal when examined using a light microscope. Electron microscopy demonstrates flattening and fusion of the podocyte foot processes in the glomeruli.]]
Answer D AnswerD::Enlarged, hypercellular glomeruli with proliferation of mesangial and endothelial cells
Answer D Explanation [[AnswerDExp::Incorrect. Enlarged, hypercellular glomeruli with proliferation of mesangial and endothelial cells using a light microscope are indicative of acute post-streptococcal glomerulonephritis. Electron microscopy demonstrates sub-epithelial immune complexes and a "lumpy-bumpy" appearance. It may present with dark urine, hypertension, and periorbital edema with or without oliguria. Acute glomerulonephritis is characterized by the onset of hematuria, proteinuria, and red blood cell casts in the urine.]]
Answer E AnswerE::“Wire looping” of capillaries
Answer E Explanation [[AnswerEExp::Incorrect. “Wire looping” of capillaries is a feature indicative of diffuse proliferative glomerulonephrits, frequently observed amoung patients with systemic lupus erythematosus (SLE).]]
Right Answer RightAnswer::C
Explanation [[Explanation::The boy in this scenario has nephrotic syndrome, characterized by proteinuria, hypoalbuminemia, and edema. Minimal change disease, also referred to as lipoid nephrosis, is the most common cause of nephrotic syndrome in very young children. It usually starts with facial edema and can be triggered by a bee sting, previous upper respiratory tract infections, drugs, or malignancies. Treatment is very effective with corticosteroids.

Educational Objective: Nephrotic syndrome (NS) is characterized by proteinuria, hypoalbuminemia and edema. Minimal change disease is the commonest cause of NS in children, and it can be effectively treated with steroids.
Educational Objective:
References: ]]

Approved Approved::Yes
Keyword WBRKeyword::Nephrotic syndrome, WBRKeyword::minimal change disease
Linked Question Linked::
Order in Linked Questions LinkedOrder::