Question

A child younger than 6 years has nephrotic syndrome that responds well to steroids. A renal biopsy is done. What will be seen under the light microscope?

• A. Nothing
• B. Loss of foot processes
• C. Tubule atrophy
• D. Crescents

Hint:

Steroid-responsive nephrotic syndrome in a young child points to minimal change disease, which looks normal on light microscopy.

Answer 1

The Correct Option is A

Step 1: Read the clinical clues.
A child under 6 years with nephrotic syndrome that responds well to steroids is the classic picture of minimal change disease. This is the most common cause of nephrotic syndrome in young children.

Step 2: Recall what minimal change disease looks like on light microscopy.
Under the light microscope, the glomeruli in minimal change disease look normal. The capillary loops, mesangium, and Bowman's capsule show no visible damage. This is why the disease used to be called nil disease or lipoid nephrosis.

Step 3: Recall where the real damage is seen.
The actual defect is at the podocyte level, the effacement, meaning flattening and fusion, of the foot processes. This change cannot be seen on light microscopy. It only shows up on electron microscopy.

Step 4: Rule out the other options.
Loss of foot processes is a real change in this disease, but it is an electron microscopy finding, not a light microscopy finding, so it does not answer what light microscopy shows. Tubule atrophy points to a chronic, longstanding kidney disease, not a steroid-responsive childhood nephrotic syndrome. Crescents are seen in rapidly progressive glomerulonephritis, a more severe disease that responds poorly to steroids.

Step 5: Why steroid response matters.
Steroid responsiveness in a young child with nephrotic syndrome is itself a strong clue for minimal change disease, since it nearly always responds to steroids, unlike focal segmental glomerulosclerosis or membranous nephropathy.

Final Answer:
On light microscopy, the glomeruli of minimal change disease appear essentially normal.