Renal Pathology — MCQs

Question 621: Mesangial deposition of electron-dense substance is seen in?

• A. IgA nephropathy (Correct Answer)
• B. Minimal change disease
• C. Membranous nephropathy
• D. Post streptococcal glomerulonephritis

Explanation: ***IgA nephropathy*** - Characterized by **mesangial deposition** of IgA-dominant immune complexes, leading to **electron-dense substance** visible on electron microscopy [1]. - Often presents with **hematuria** and **episodic proteinuria**, frequently following infections. *Post streptococcal glomerulonephritis* - Typically involves **subepithelial immune complex deposition**, resulting in **humps on the glomerular basement membrane** rather than mesangial deposits. - Associated with **hematuria** and **edema**, occurring after a streptococcal infection. *Membranous nephropathy* - Characterized by **subepithelial immune complex deposits** along the capillary walls causing a **thickened membrane**, not mesangial deposits. - Presents with **nephrotic syndrome**, features such as heavy proteinuria, edema, and hyperlipidemia. *Minimal change disease* - Primarily involves **loss of podocyte foot processes** and does not have significant deposits observable on microscopy, including electron-dense substance [1]. - Commonly seen in **children**, presenting with **nephrotic syndrome** and good response to steroids [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 927-928.