• Cholecystitis (Greek, -cholecyst, "gallbladder",combined with the suffix -itis, "inflammation")is inflammation of the gallbladder, whichoccurs most commonly due to obstruction ofthe cystic duct with gallstones (cholelithiasis).
Acute Cholecystitis• Acute calculous cholecystitis is an acuteinflammation of the gallbladder, precipitated90% of the time by obstruction of the neck orcystic duct.• It is the primary complication of gallstonesand the most common reason for emergencycholecystectomy.
Aacalculous cholecystitis• Cholecystitis without gallstones calledacalculous cholecystitis may occur in severelyill patients and accounts for about 10% ofpatients with cholecystitis.
Pathogenesis.• Acute calculous cholecystitis results fromchemical irritation and inflammation of theobstructed gallbladder.
• The action of mucosal phospholipaseshydrolyzes luminal lecithins to toxiclysolecithins.
• The normally protective glycoprotein mucuslayer is disrupted, exposing the mucosalepithelium to the direct detergent action ofbile salts.
• Prostaglandins released within the wall of thedistended gallbladder contribute to mucosal andmural inflammation.
• Gallbladder dysmotility develops; distentionand increased intraluminal pressurecompromise blood flow to the mucosa.
Pathogenesis• Acute acalculous cholecystitis is thought to resultfrom ischemia. The cystic artery is an end arterywith essentially no collateral circulation.
Risk factors for acute acalculouscholecystitis include:(1) Sepsis with hypotension and multisystemorgan failure;(2) Immunosuppression;(3) Major trauma and burns;(4) Diabetes mellitus; and(5) Infections.
Morphology.In acute cholecystitis the gallbladder is usuallyenlarged and tense, and it may assume abright red or blotchy, violaceous to green-black discoloration, imparted by subserosalhemorrhages.
• The serosal covering is frequently layered byfibrin and, in severe cases, by a definitesuppurative, coagulated exudate.
Morphology• In calculous cholecystitis, an obstructingstone is usually present in the neck of thegallbladder or the cystic duct.
• The gallbladder lumen may contain one ormore stones and is filled with a cloudy orturbid bile that may contain large amounts offibrin, pus, and hemorrhage.
• In mild cases the gallbladder wallisthickened, edematous, and hyperemic.
• In more severe cases it is transformed into agreen-black necrotic organ, termedgangrenous cholecystitis,with small-to-large perforations.
• The invasion of gas-forming organisms,notably clostridia and coliforms, may causean acute “emphysematous” cholecystitis.
Clinical Features.• An attack of acute cholecystitis begins withprogressive right upper quadrant orepigastric pain, frequently associated withmild fever, anorexia, tachycardia, sweating,nausea, and vomiting.
• The pain may be referred pain that is felt inthe right scapula rather than the right upperquadrant or epigastric region (Boas sign).
• It may also correlate with eating greasy, fatty,or fried foods.
• The Murphy sign is specific, but not sensitivefor cholecystitis.
• Elderly patients and those with diabetes mayhave vague symptoms that may not includefever or localized tenderness.
• More severe symptoms such as high fever,shock and jaundice indicate the developmentof complications such as• abscess formation,• perforation or• ascending cholangitis.
• Another complication, gallstone ileus,occurs if the gallbladder perforates and formsa fistula with the nearby small bowel, leadingto symptoms of intestinal obstruction.
• Clinical symptoms of acute acalculouscholecystitis tend to be more insidious, sincesymptoms are obscured by the underlyingconditions precipitating the attacks.
• As a result of either delay in diagnosis or thedisease itself, the incidence of gangrene andperforation is much higher in acalculous thanin calculous cholecystitis.
Chronic Cholecystitis• Chronic cholecystitis may be a sequel torepeated bouts of mild to severe acutecholecystitis,• but in many instances it develops in theapparent absence of antecedent attacks.
• Since it is associated with cholelithiasis inmore than 90% of cases, the patientpopulations are the same as those forgallstones.
• supersaturation of bilepredisposes to both chronic inflammationand, in most instances, stone formation.
• Unlike acute calculous cholecystitis,obstruction of gallbladder outflow is not arequisite.
• , the symptoms of calculous chroniccholecystitis are biliary colic to indolent rightupper quadrant pain and epigastric distress.
Morphology.• The morphologic changes in chroniccholecystitis are extremely variable andsometimes minimal.
• The serosa is usually smooth andglistening but may be dulled by subserosalfibrosis.• Dense fibrous adhesions
• On sectioning, the wall is variably thickened,and has an opaque gray-white appearance.
• In the uncomplicated case• the lumen contains fairly clear, green-yellow,mucoid bile and usually stones. The mucosaitself is generally preserved.
Microscopy• In the mildest cases, only scatteredlymphocytes, plasma cells, and macrophagesare found in the mucosa and in thesubserosal fibrous tissue.
• In more advanced cases there ismarked subepithelial and subserosalfibrosis, accompanied by mononuclearcell infiltration.
• Outpouchings of the mucosal epitheliumthrough the wall(Rokitansky-Aschoffsinuses) may be quite prominent.
Acute superimposed on chroniccholecystitisSuperimposition of acuteinflammatory changes impliesacute exacerbation of an already chronicallyinjured gallbladder.
Porcelain gallbladder• In rare instances extensive dystrophiccalcification within the gallbladder wall may yield aporcelain gallbladder, notable for a markedlyincreased incidence of associated cancer.
• Xanthogranulomatous cholecystitis is also arare condition in which the gallbladder has amassively thickened wall, isshrunken, nodular, and chronically inflamedwith foci of necrosis and hemorrhage.
• Finally, an atrophic, chronicallyobstructed gallbladder maycontain only clear secretions, acondition known ashydrops of the gallbladder.
Clinical Features.• Usually characterized by recurrent attacks ofeither steady or colicky epigastric or rightupper quadrant pain.
• Nausea, vomiting, and intolerance for fattyfoods are frequent accompaniments.