Acute cholecystitis with chronic cholecystitis

This code signifies an inflammatory condition of the gallbladder where an acute exacerbation of cholecystitis occurs in a patient with pre-existing chronic cholecystitis. It indicates a superimposed acute inflammation on a chronically inflamed gallbladder, often characterized by fibrosis and thickening of the gallbladder wall.

Apply this code when documentation clearly states "acute on chronic cholecystitis" or "acute exacerbation of chronic cholecystitis." This diagnosis is typically supported by imaging findings (e.g., ultrasound, CT scan) showing signs of both acute inflammation (e.g., gallbladder wall thickening, pericholecystic fluid) and chronic changes (e.g., contracted gallbladder, cholelithiasis).

• Do not use this code if only acute cholecystitis or only chronic cholecystitis is documented; separate codes exist for those distinct conditions.
• Ensure the documentation explicitly links the acute episode to a pre-existing chronic state.
• Consider sequencing this code as the primary diagnosis if it is the main reason for the encounter, followed by any associated conditions like cholelithiasis (K80.-).