A 62-year-old man presents with nephrotic syndrome and macroglossia. Renal biopsy reveals amorphous eosinophilic deposits in glomeruli that show apple-green birefringence with Congo red stain under polarized light. Which type of amyloid is most likely?

• A AA amyloid
• B ATTR amyloid
• C Aβ2M amyloid
• D AL amyloid ✓

Explanation

AL amyloidosis (immunoglobulin light chain) is associated with plasma cell dyscrasia and commonly causes macroglossia. AA amyloidosis is secondary to chronic inflammatory diseases and does not cause macroglossia. Aβ2M is dialysis-related, and ATTR is transthyretin amyloidosis. The presence of macroglossia strongly points to AL amyloidosis.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.