Ultrasonography is an accurate technique for the diagnosis of gastrointestinal tumors in patients without localizing symptoms.

Introduction And Objectives: This study compared the accuracy of ultrasonography in the diagnosis of gastrointestinal tumors in patients with several degrees of clinical suspicion.

Material And Methods: We recruited patients that were suspect for gastrointestinal neoplasia but with no evidence of localizing symptoms (group A), and patients that were suspect for colon cancer (group B) or for gastric cancer (group C). Accuracy in the diagnosis was compared for: gastric cancer in groups A and C, and for colon cancer in groups A and B. The comparison was made by using the contingency coefficient, which quantifies coincidence of endoscopic and ultrasonographic diagnoses.

Results: Seventy-nine patients were included in group A (48 males), wherein 12 colon and 5 gastric neoplasms were detected. Group B was comprised of 153 patients (78 males) and included 66 patients with colorectal cancer (CCR). Group C contained 58 patients (35 males), 31 of whom were diagnosed with gastric cancer. The accuracy of sonography for diagnosing colon cancer was 95.5% for group A and 87.5% for group B. The contingency coefficient for endoscopy vs. ultrasonography was greater for group A: 0.658 than for group B: 0.549. The diagnostic accuracy for gastric cancer was 97.4% for group A and 86.2% for group C. The contingency coefficient between endoscopic and ultrasonographic diagnoses was also greater in group A (0.618) than in group C (0.588).

Conclusions: The accuracy of ultrasonography in diagnosing colon and gastric cancer is not lower in patients without localizing symptoms.