Myeloma Kidney : Morphology
The light chain casts in myeloma kidney appear as dense pink amorphous masses within the distal and collecting tubules. They are often fractured and surrounded by macrophages or multinucleated giant cells. The tubular epithelium may be flattened or denuded.The surrounding interstitium shows chronic inflammation or granulomatous response with fibrosis. In addition, there may be interstitial amyloid deposits, calculi, or overt infection with acute inflammatory infiltrate.