Magnifying narrow-band imaging with acetic acid to diagnose early colorectal cancer.

AIM: To evaluate the diagnostic characteristics of magnifying endoscopy with acetic acid spray and narrow-band imaging (MA-NBI) for early colorectal cancer. METHODS: We conducted a prospective study to evaluate the diagnostic characteristics of MA-NBI in differentiating early colorectal adenocarcinomas from adenomas. To compare the results, we used magnifying endoscopy with NBI (M-NBI) and magnifying endoscopy with crystal violet staining (M-CV). The study was performed in 2 phases. In phase 1, 10 colonoscopists at our institution were shown still photographs of 35 colorectal polyps (24 adenocarcinomas and 11 adenomas) in M-NBI, MA-NBI, and M-CV. They made diagnostic predictions using a five-grade scoring evaluation. We plotted receiver operating characteristic curves and compared the areas under the curves (AUCs). In phase 2, colorectal polyps measuring ≥ 8 mm were prospectively enrolled. During real-time colonoscopy, one of the 7 colonoscopists scored the lesion as an adenocarcinoma or an adenoma and assigned a level of confidence to the prediction (high or low). We calculated the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each method and compared the proportions of high-confidence predictions. RESULTS: In phase 1, the mean ± SD AUCs were 0.64 ± 0.031 in M-NBI, 0.71 ± 0.066 in MA-NBI, and 0.76 ± 0.059 in M-CV (P < 0.05 for M-NBI vs MA-NBI, P < 0.001 for M-NBI vs M-CV, and not significant for MA-NBI vs M-CV). In phase 2, 84 patients with 91 lesions (46 adenocarcinomas and 45 adenomas) were enrolled. The diagnostic characteristics were as follows: 73% accuracy, 85% sensitivity, 60% specificity, 68% PPV, and 79% NPV in M-NBI; 73% accuracy, 80% sensitivity, 64% specificity, 70% PPV, and 76% NPV in MA-NBI; and 73% accuracy, 83% sensitivity, 62% specificity, 69% PPV, and 78% NPV in M-CV. The proportions of high-confidence predictions were 57% in M-NBI, 75% in MA-NBI, and 76% in M-CV (P < 0.005 for M-NBI vs MA-NBI, P < 0.0005 for M-NBI vs M-CV, and P = 1.0 for MA-NBI vs M-CV). CONCLUSION: MA-NBI is useful for differentiating early colorectal adenocarcinomas from adenomas.

[Pancreatic cancer in a patient with congenital agenesis of the dorsal pancreas].

A 65-year-old man with back pain showed a hypovascular lesion of the head of the pancreas on dynamic computed tomography and abdominal ultrasonography. The distal portion of the pancreas was not visible. Endoscopic retrograde cholangiopancreatography revealed pancreatic duct obstruction, and the duodenal minor papilla was not visible. Therefore, we diagnosed the patient's condition as stage IVa pancreatic cancer with congenital agenesis of the dorsal pancreas. The patient underwent successful chemotherapy with 3 courses of gemcitabine and S-1, which was followed by pancreaticoduodenectomy. Pathological staging revealed invasive ductal carcinoma, pT3, pN0, pM0, stage III. We report a rare case of pancreatic cancer with congenital agenesis of the dorsal pancreas.