Page 246 - AIDSBK23C

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PANCREAS IN AIDS

The pancreas in persons with AIDS may show opportunistic infections or neoplasms,
evidence of recent or remote pancreatitis with hyperamylasemia, and acinar dilation.
Opportunistic infections include mycobacteriosis, toxoplasmosis, cytomegalovirus (CMV),
cryptococcosis, and pneumocystosis. Malignant lymphoma involves the pancreas in AIDS about
twice as often as Kaposi's sarcoma (Table 5). In general, life-threatening pancreatic lesions are
uncommon in AIDS and most opportunistic infections and neoplasms occur in pancreas in the
setting of widespread dissemination. Non-specific pathologic changes may be seen in the
pancreas in up to 90% of persons with AIDS. These changes may include acinar atrophy,
decreased acinar cell zymogen granules, acinar nuclear abnormalities, steatosis with increased
lipid droplets in acinar cytoplasm, and focal necrosis. The acinar atrophy and steatosis suggest a
nutritional problem. [993,994]
Pancreatitis in patients with AIDS may be accompanied by hyperamylasemia and
hyperuricemia that represents the effect of renal insufficiency or macroamylasemia associated
with polyclonal gammopathy from B-lymphocyte activation. Serum amylase and lipase can be
performed along with radiologic imaging procedures to demonstrate an enlarged pancreas and
heterogenous peripancreatic tissue. Pancreatitis can occur in association with opportunistic
infections involving the pancreas, particularly cytomegalovirus.[993]
Despite the prevalence of tuberculosis worldwide, pancreatic tuberculosis with HIV
infection is rare. The most common presentation of feve and abdominal pain is non-specific.
Pancreatic tuberculosis tends to masquerade as a pancreatic malignancy, cystic tumor, or
pseudocyst. Microscopically, granuloma formation is poor, but acid fast organisms are
numerous.[995]
Risk factors for pancreatitis include antiretroviral therapy involving any of the following:
didanosine, stavudine, lamivudine, and protease inhibitors. Additional drugs implicated include
pentamidine, cotrimoxazole, antimycobacterials, and chemotherapy agents. Additional risk
factors typical of pancreatitis regardless of HIV status include alcohol abuse, biliary tract
disease, and hypertriglyceridemia. Most AIDS patients with acute pancreatitis do not have a
severe course, and the prevalence of severe disease is similar to that of the general population,
even though the etiologies may be different.[260,996]
Pancreatic ductal changes may be observed in half of AIDS patients undergoing
endoscopic retrograde pancreatography (ERCP). These changes, which resemble those of
pancreatitis, are often seen in association with AIDS-related sclerosing cholangitis. The
observed abnormalities may include dilations, short stenoses of the main pancreatic duct, and
irregularities in side branches, all features that are suggestive of chronic pancreatitis. The serum
amylase may be increased in these cases. Infection of the pancreatic or hepatobiliary ducts by
CMV, cryptosporidiosis, microsporidiosis, or mycobacteria may produce irregular ductular
narrowing and dilation, which may resemble sclerosing cholangitis.[997]
Pediatric patients may have nonspecific pancreatic changes including edema,
inflammation, fibrosis, ductular and acinar inspissated secretions, and macronesia. Though acute
pancreatitis is reported in 17% of pediatric patients with AIDS, histologic changes of acute and
chronic pancreatitis are typically mild at autopsy. Involvement by opportunistic infections is
focal and rare.[998]