Imaging of Abdominal Solid Organ and Peritoneal Tuberculosis

Abstract

Compared to pulmonary tuberculosis (TB), extrapulmonary TB occurs much less frequently, with abdominal TB comprising a small subset of extrapulmonary TB. Although a variety of imaging modalities are available, computed tomography is the single most useful technique for evaluating TB involving the abdominal solid organs and peritoneal cavity. The miliary, macronodular, serohepatic, and cholangitic forms of hepatobiliary TB present as rim-enhancing parenchymal hypodensities, subcapsular lesions that sugar-coat and scallop the liver surface, as well as bile duct thickening, strictures, and periductal miliary calcifications. Gall bladder and pancreatic TB are very rare and mimic malignancy but the presence of necrotic lymphadenopathy, ascites, liver, spleen, or ileocecal lesions may suggest the diagnosis. Splenic TB presents as rim-enhancing hypodensities, calcifications, or endarteritis-related infarcts. Peritoneal TB, a relatively common form of abdominal TB, involves the peritoneal lining, mesentery, and omentum, and is caused by contiguous spread from the fallopian tube, bowel, or psoas abscess. The four forms of peritoneal TB are wet-ascitic, dry-plastic, fixed-fibrotic, and “abdominal cocoon.” Tuberculous lymphadenitis, the commonest form of abdominal TB, occurs secondary to small bowel or right colon infection and presents as enlarged, matted, enhancing peripancreatic and superior mesenteric nodes that progress to fibrosis and calcification following treatment and healing.