It is associated with many causes including vasculitis, chemotherapy, major trauma or burns.The presentation of acalculous cholecystitis is similar to calculous cholecystitis. Patients are more likely to have yellowing of the skin (jaundice) than in calculous cholecystitis. Ultrasonography or computed tomography often shows an immobile, enlarged gallbladder. Treatment involves immediate antibiotics and cholecystectomy within 24–72 hours. Chronic cholecystitis
Chronic cholecystitis occurs after repeated episodes of acute cholecystitis and is almost always due to gallstones. Chronic cholecystitis may be asymptomatic, may present as a more severe case of acute cholecystitis, or may lead to a number of complications such as gangrene, perforation, or fistula formation.Xanthogranulomatous cholecystitis (XGC) is a rare form of chronic cholecystitis which mimics gallbladder cancer although it is not cancerous. It was first reported in the medical literature in 1976 by McCoy and colleagues. Mechanism
Blockage of the cystic duct by a gallstone causes a buildup of bile in the gallbladder and increased pressure within the gallbladder. Concentrated bile, pressure, and sometimes bacterial infection irritate and damage the gallbladder wall, causing inflammation and swelling of the gallbladder. Inflammation and swelling of the gallbladder can reduce normal blood flow to areas of the gallbladder, which can lead to cell death due to inadequate oxygen. Diagnosis
The diagnosis of cholecystitis is suggested by the history (abdominal pain, nausea, vomiting, fever) and physical examinations in addition to laboratory and ultrasonographic testing. Boass sign, which is pain in the area below the right scapula, can be a symptom of acute cholecystitis.
Blood tests
In someone suspected of having cholecystitis, blood tests are performed for markers of inflammation (e.g. complete blood count, C-reactive protein), as well as bilirubin levels in order to assess for bile duct blockage. Complete blood count typically shows an increased white blood count (12,000–15,000/mcL). C-reactive protein is usually elevated although not commonly measured in the United States. Bilirubin levels are often mildly elevated (1–4 mg/dL). If bilirubin levels are more significantly elevated, alternate or additional diagnoses should be considered such as gallstone blocking the common bile duct (common bile duct stone). Less commonly, blood aminotransferases are elevated. The degree of elevation of these laboratory values may depend on the degree of inflammation of the gallbladder. Imaging
Right upper quadrant abdominal ultrasound is most commonly used to diagnose cholecystitis. Ultrasound findings suggestive of acute cholecystitis include gallstones, pericholecystic fluid (fluid surrounding the gallbladder), gallbladder wall thickening (wall thickness over 3 mm), dilation of the bile duct, and sonographic Murphys sign. Given its higher sensitivity, hepatic iminodiacetic acid (HIDA) scan can be used if ultrasound is not diagnostic. CT scan may also be used if complications such as perforation or gangrene are suspected. Histopathology
Histopathology is indicated if preoperative imaging and/or gross examination gives a suspicion of gallbladder cancer. Differential diagnosis
Many other diagnoses can have similar symptoms as cholecystitis. Additionally the symptoms of chronic cholecystitis are commonly vague and can be mistaken for other diseases.