It is important to have a knowledge of common diseases while carrying out abdominal ultrasound screening. Moreover, relatively rare diseases should also be recognized.

Hepatic angiomyolipoma shows up as an extremely hyperechoic mass on ultrasonography with an acoustic shadow and an early venous return. Sclerosing hemangioma is an atypical type of cavernous hemangioma with degenerative changes. Primary hepatic lymphoma appears as an extremely hypoechoic mass with a penetrating vessel. Combined hepatocellular cholangiocarcinoma is a primary hepatic malignant tumor that has characteristics of both hepatocellular carcinoma and cholangiocarcinoma. Intraductal papillary neoplasm of the bile duct (IPNB) is a precancerous lesion that produces mucus and shows dilation of the bile duct upon imaging. Fontan-associated liver disease is a hepatic disorder that arises after Fontan surgery. Long-term mild congestion causes liver cirrhosis or various hepatic tumors.

To clarify the usefulness of additional images, we examined their effect on the categorization criteria for gastric cancer. We studied 51 cases of gastric cancer detected at our center from April 2012 to March 2015. In 46 cases, the lesions were visualized in the regular 8 positions. Additional images of the lesions were taken in 38 cases. In 21 cases, the additional images resulted in a change of categorization, and in 17 of them, early stages of cancer were diagnosed. Of these 17 cases, 5 were judged as C-2 in the regular 8 positions, and as C-4 or higher by taking additional images. Ten cases were judged as C-3b in the regular 8 positions, and as C-4 or higher by taking additional images. There were 13 cases of advanced cancer, and all were judged as C-4 or higher in the regular 8 positions. From this examination, it is evident that taking additional images plays a significant role in detecting gastric cancer early. It is necessary for radiology technologists engaged in mass screening for gastric cancer to gain an extensive understanding of lesion images and take appropriate additional images. We believe that it is thus possible to improve the accuracy of such mass screening for gastric cancer.

Objective: To determine the causes of false-negative diagnoses of gastric cancer to improve the accuracy of endoscopy.

Subjects and methods: At our institution, 1,088 cases of gastric cancer were diagnosed between April 2011 and March 2017. Over a 3-year period after screening endoscopy, we retrospectively analyzed 211 false-negative cases.

Results: Of the enrolled patients, 168 were males and 43 were females. Their mean age was 70±6.0 years. Forty-five, 102, and 64 lesions were observed in the upper, middle, and lower regions of the stomach. The mean tumor diameter was 15±13 mm. Further, 161, 40, and 10 lesions were diagnosed as mucosal cancer, submucosal cancer, and advanced cancer, respectively. The early cancer and mucosal cancer rates were 95.2% and 76.3%, respectively. At the three endoscopy intervals of up to 1 year, 1-2 years, and 2-3 years, the early cancer rates were 99.1%, 97.1%, and 73.1%, respectively, and the mucosal cancer rates were 81.2%, 76.4%, and 53.8%, respectively. The early cancer and mucosal cancer rates at the endoscopy interval of 2-3 years were significantly lower than those at the endoscopy intervals of up to 1 year and 1-2 years. For the upper, middle, and lower regions of the stomach, the early cancer rates were 86.7%, 97.1%, and 98.4%, respectively, and the mucosal cancer rates were 51.1%, 82.4%, and 84.4%, respectively. The early and mucosal cancer rates for the upper region of the stomach were significantly lower than those for the middle and lower regions. After analyzing previous endoscopic images, 50 false-negative cases involving the submucosal and deeper layers were classified as follows: eight cases of poorly observed lesions, 20 cases of poorly detected lesions, and 22 cases of lesions that were difficult to detect. More careful observation and detection were required for lesions in the upper region of the stomach as five lesions were poorly observed and 11 lesions were difficult to detect in this region.

Conclusions: To improve the accuracy of endoscopy, it is important to reassess gastric cancer cases using comprehensive endoscopy.

Enlargement of the splenic artery and the hepatoduodenal ligament lymph nodes was detected in a 58-year-old woman during abdominal ultrasonography performed as part of a complete medical check-up conducted at our hospital in December 2017. An ulcerative lesion and mucosal fold thickening in the stomach were observed on gastric radiography examination. Circumferential mucosal fold thickening and an irregular ulcer extending from the angle to the body of the stomach were observed on performing upper gastrointestinal endoscopy. The extension of the gastric wall was adequate. Analysis of the biopsied specimen from the ulcerated region led to the diagnosis of diffuse large B-cell lymphoma (DLBCL), and the patient was referred to a hematology hospital. A thorough examination revealed stage III (Ann Arbor staging) DLBCL. After six cycles of CHOP (combination of cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy plus rituximab, the patient achieved complete remission. We believe that detailed observation and comprehensive knowledge of abdominal ultrasonography findings along with careful interpretation of the gastric X-ray images were instrumental in achieving an accurate diagnosis in this case.