Efficacy of gel immersion endoscopic ultrasonography for delineating the duodenal papilla and pancreatobiliary ducts: A retrospective study with video.

Objectives: Endoscopic ultrasonography is an important examination for periampullary diseases. The duodenum is filled with water to ensure a clear image and distend the duodenal wall without burying the papilla within duodenal folds; however, peristalsis frequently makes it difficult to maintain water within the duodenum. The gel immersion method (intestine is filled with viscosity gel) has recently been attracting attention. We evaluated the usefulness of using this method for endoscopic ultrasonography to detect and delineate the major duodenal papilla. Methods: Fifty-nine consecutive patients who underwent gel immersion-endoscopic ultrasonography between February and March 2021 were included retrospectively. The papilla was observed by filling the duodenum with clear viscosity gel. Outcomes were the rate of duodenal distention, delineation rates of the papilla, the time required for delineation, volume of the gel used, and adverse events. Results: Duodenal distention was excellent, good, and poor in 58%, 34%, and 7% of cases, respectively. The delineation rates of the papilla in the axial and longitudinal views were 98% and 66%, respectively. The median time required to delineate the papilla in each view was 3.1 (range, 1.0-1.4) and 7.9 (1.9-28.6) min; the median volume of the gel used was 80 (30-150) ml and 100 (50-200) ml, respectively. No adverse events were noted. Conclusions: Gel immersion-endoscopic ultrasonography provided sufficient duodenal distention, leading to high rates of detection and delineation of the papilla using a small volume of gel within a short time. This method may be useful for the evaluation of the ampullary region.

Role of Endoscopic Ultrasound in the Diagnosis of Pancreatic Neuroendocrine Neoplasms.

Although pancreatic neuroendocrine neoplasms (PNENs) are relatively rare tumors, their number is increasing with advances in diagnostic imaging modalities. Even small lesions that are difficult to detect using computed tomography or magnetic resonance imaging can now be detected with endoscopic ultrasound (EUS). Contrast-enhanced EUS is useful, and not only diagnosis but also malignancy detection has become possible by evaluating the vascularity of tumors. Pathological diagnosis using EUS with fine-needle aspiration (EUS-FNA) is useful when diagnostic imaging is difficult. EUS-FNA can also be used to evaluate the grade of malignancy. Pooling the data of the studies that compared the PNENs grading between EUS-FNA samples and surgical specimens showed a concordance rate of 77.5% (κ-statistic = 0.65, 95% confidence interval = 0.59-0.71, p < 0.01). Stratified analysis for small tumor size (2 cm) showed that the concordance rate was 84.5% and the kappa correlation index was 0.59 (95% confidence interval = 0.43-0.74, p < 0.01). The evolution of ultrasound imaging technologies such as contrast-enhanced and elastography and the artificial intelligence that analyzes them, the evolution of needles, and genetic analysis, will further develop the diagnosis and treatment of PNENs in the future.

An intact boundary between the tumor and inner hypoechoic layer discriminates T1 lesions among sessile elevated gallbladder cancers.

BACKGROUND: The depth of invasion determines the surgical method for treating gallbladder cancer (GBC). However, the preoperative correct diagnosis of invasion depth, especially discrimination of T1 lesions among sessile elevated GBCs, is difficult. We investigated the utility of preoperative endoscopic ultrasound (EUS) findings for diagnosing the invasion depth. METHODS: We studied a sessile elevated GBC specimen diagnosed as a T1 lesion before developing our study protocol. EUS evidenced an intact boundary between the tumor and the inner hypoechoic layer (the intact boundary sign). To evaluate the potential of using this sign to diagnose T1 GBC as a primary outcome indicator, we retrospectively analyzed patients who underwent surgical resection of sessile elevated GBCs between April 2009 and March 2020. RESULTS: Of the 26 surgically resected sessile elevated GBC specimens, 20 were included and six were excluded due to difficulty in evaluating the overall tumor or layer structure. The Kappa coefficient for interobserver agreement regarding the intact boundary sign was 0.733. The sensitivity and specificity of the sign for diagnosing T1 lesions were 0.857 and 1.000, respectively. CONCLUSION: This new EUS finding could guide the accurate diagnosis of T1 lesions in patients with sessile elevated GBC.

HER2-positive gastric cancer identified by serum HER2: A case report.

Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are the current standards methods for the determination of tissue human epidermal growth factor receptor 2 (HER2) status in gastric cancer, as for breast cancer. However, HER2-positive gastric cancer occasionally exhibits heterogeneous tissue HER2 overexpression, raising concern regarding false-negative results in unresectable cases diagnosed by biopsy samples. Serum HER2, the concentration of the extracellular domain of HER2 protein shed into the bloodstream, has the potential to supplement the use of IHC or FISH to determine HER2 status. However, the clinical significance of serum HER2 has not been well studied in gastric cancer. The present study describes an illustrative case of metastatic gastric cancer initially diagnosed as HER2-negative (IHC score 1+). The patient exhibited an elevated serum HER2 level, which prompted a reevaluation of the tissue by IHC, using an alternative antibody, and FISH; re-biopsy analyses confirmed the case as HER2-positive, and trastuzumab was subsequently added to the combination chemotherapy with capecitabine and cisplatin. Serum HER2 may aid in avoiding false-negative diagnoses of HER2 gastric cancer.