A liver biopsy from a patient with alcoholic hepatitis shows hepatocytes containing ropey eosinophilic cytoplasmic inclusions surrounded by clear halos. On immunohistochemistry these Mallory-Denk bodies are composed predominantly of:

• A Aggregated amyloid A fibrils stained by Congo red
• B Misfolded alpha-synuclein with Lewy body morphology
• C Alpha-1 antitrypsin retained within dilated endoplasmic reticulum
• D Ubiquitinated cytokeratin 8 and 18 intermediate filaments ✓

Explanation

Mallory-Denk bodies are tangled masses of intermediate filaments, chiefly cytokeratins 8 and 18, heavily ubiquitinated because failed proteasomal degradation marks them for removal. They typify alcoholic steatohepatitis, Wilson disease and chronic cholestasis. Alpha-1 antitrypsin appears as PAS-positive diastase-resistant globules in periportal hepatocytes, amyloid deposits are extracellular, and alpha-synuclein defines Lewy bodies seen in Parkinson disease and dementia with Lewy bodies.

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.