What are the typical CT (Computed Tomography) findings in a young adult from a developing country suspected of having abdominal Tuberculosis (TB)?

CT Findings of Abdominal Tuberculosis

In young adults from developing countries with suspected abdominal TB, CT typically demonstrates peritoneal involvement (77.5% of cases) with either ascites or peritoneal/omental thickening, lymphadenopathy (47% of cases, predominantly peripancreatic and mesenteric), bowel wall thickening (38%), and less commonly solid organ involvement (20%). 1

Most Common CT Features

Peritoneal Disease (Present in 77.5% of Cases)

• "Wet peritonitis" manifests as ascites, seen in 55% of abdominal TB cases 1
• "Dry peritonitis" shows peritoneal, mesenteric, or omental thickening or mass formation without ascites 1
• Smooth thickening of the parietal peritoneum is characteristic 2
• Irregular soft-tissue densities in the omental area are highly suggestive of TB 3
• Complex nature of ascites (not simple fluid) helps distinguish TB from other causes 4

Lymphadenopathy (Present in 46.9% of Cases)

• Predominantly involves peripancreatic and mesenteric compartments, which is characteristic for TB rather than other pathologies 4
• Nodes typically show low-density centers with thick solid rims after IV contrast administration 3
• Multilocular appearance of lymph nodes after contrast is highly suggestive 3
• Adenopathy adjacent to sites of gastrointestinal tract involvement is common 4

Gastrointestinal Involvement (Present in 38% of Cases)

• Bowel wall thickening is a frequent finding 1
• A disorganized appearance of soft-tissue densities, fluid, and bowel loops forming a poorly defined mass is characteristic 3

Solid Organ Involvement (Present in 20.4% of Cases)

• Hepatomegaly and splenomegaly may be present 4
• Intrasplenic and intrahepatic masses can occur 4
• Liver, spleen, biliary tract, pancreas, and adrenals are rarely affected but more likely in HIV-positive patients 5

Genitourinary Manifestations

• Hydronephrosis is a common manifestation of genitourinary TB 2
• Calcifications in the genitourinary tract are characteristic 2

Critical Diagnostic Considerations

High-Risk Populations Requiring Heightened Suspicion

• Recent immigrants from TB-endemic countries 2
• HIV-positive patients (who may have atypical presentations and multi-organ involvement) 2, 5
• Patients with family history of TB 2
• Those with underlying chronic diseases, intravenous drug abuse, alcoholism, cirrhosis, or on steroid therapy 4

Important Diagnostic Pitfalls

• Abdominal TB can mimic diffuse peritoneal malignancy, lymphoma, peritoneal carcinomatosis, and peritoneal mesothelioma 2, 3
• False positive oncologic imaging (such as Tc-99m CEA scanning) can occur, suggesting tumor recurrence when TB is actually present 2
• Multi-organ involvement should raise suspicion for TB rather than other diagnoses 2
• TB should be considered in patients with obscure abdominal symptoms and general systemic complaints 2

Optimal Imaging Protocol

• CT with IV contrast is essential to demonstrate the characteristic low-density centers within enlarged nodes and to better characterize peritoneal and omental involvement 3, 4
• CT reliably demonstrates the entire range of findings but requires interpretation in light of clinical and laboratory data 1

Diagnostic Algorithm for Suspected Abdominal TB

• Maintain high index of suspicion in young adults from developing countries presenting with obscure abdominal symptoms 2
• Obtain CT with IV contrast as the primary imaging modality 3, 4
• Look specifically for the characteristic triad: peritoneal involvement, peripancreatic/mesenteric lymphadenopathy with low-density centers, and bowel wall thickening 1, 3, 4
• Pursue less invasive diagnostic procedures (laparoscopy, biopsy, or trial of antituberculous therapy) rather than laparotomy when CT features are suggestive 3
• Establish definitive diagnosis through standard microbiological and histological techniques 2