A 45-year-old alcoholic man has Mallory-Denk bodies on liver biopsy. What is the molecular composition of these inclusions?
- A Crystallized alpha-1 antitrypsin in ER cisternae
- B Copper-laden lysosomes in periportal hepatocytes
- C Aggregates of ubiquitinated keratin 8 and keratin 18 intermediate filaments ✓
- D Ferritin and hemosiderin deposits from iron overload
Correct answer: C. Aggregates of ubiquitinated keratin 8 and keratin 18 intermediate filaments
Explanation
Mallory-Denk bodies are cytoplasmic inclusions composed of misfolded, ubiquitinated keratin 8 and keratin 18 intermediate filament proteins. They occur in alcoholic hepatitis, NAFLD/NASH, Wilson disease, and other hepatocyte injuries. Alpha-1 antitrypsin inclusions are PAS-positive diastase-resistant eosinophilic globules in periportal hepatocytes. Copper deposits characterize Wilson disease; hemosiderin indicates hemochromatosis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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