Evaluation of gastric submucosal tumors using endoscopically visualized features with submucosal endoscopy

MR imaging features of pancreatic schwannoma: a Chinese case series and a systematic review of 25 cases

BACKGROUND

There is a paucity of existing literature centering on the magnetic resonance (MR) imaging features of pancreatic schwannomas, due to the neoplasm's nonspecific presentation and its rarity. We aimed to identify the characteristic imaging features of pancreatic schwannoma.

METHODS

This retrospective search was conducted for histologically confirmed pancreatic schwannoma in multi-institutional database of pathology. Abdominal magnetic resonance imaging (MRI) was performed before histologic examination and their MR imaging studies were independently reviewed. The search yielded six adults (mean age, 46 years) with a definitive histologic postoperative diagnosis of single pancreatic schwannoma each. Additionally, a comprehensive English and Chinese literature review for pancreatic schwannoma and reported MR-imaging findings since 1961 was also conducted. MR imaging features of those cases in the literature were analyzed, summarized and compared with our case series.

RESULTS

This rare entity appeared to be a well-circumscribed, exophytic, oval or round pancreatic mass with a mean greatest diameter of 3.7 cm. Five schwannomas were located in the pancreatic head-neck and one in the pancreatic tail. On MRI, all cases appeared hypointense on T1-weighted images, inhomogeneous hyperintense on T2-weighted images, and hyperintense on diffusion-weighted images. The mean apparent diffusion coefficient (ADC) values of pancreatic schwannoma were 1.11 ± 0.29 × 10- 3 mm2/s and significantly lower than the surrounding pancreas. The lesion-to-pancreas signal intensity ratio (SIR) at unenhanced T1-weighted images was 0.53 ± 0.07. On dynamic contrast-enhanced MRI, most of the lesions (67%, 4/6) showed homogeneously iso- or hypointense on arterial and portal venous phases, and hyperenhancement on delayed phase compared with the surrounding pancreas. In our analysis of the time intensity curves, all cases exhibited a gradual enhancement pattern.

CONCLUSIONS

A well-circumscribed mass displaying inhomogeneous hyperintensity on T2, marked hypointensity on T1, hyperintensity on DWI, and with early slight enhancement at arterial phase and progressive enhancement at portal venous and delayed phase, may suggest the diagnosis of pancreatic schwannoma.

Simplified Submucosal Tunneling Biopsy Using Clip-With-Line Traction and Closure for Gastric Subepithelial Lesion

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) has emerged as a standard and convenient method for the sampling of subepithelial lesions (SELs). Immunohistological analysis is required to definitively distinguish mesenchymal tumors; however, EUS-FNA provides insufficient material to achieve this, especially for small SELs < 2 cm. We therefore previously reported a novel submucosal tunneling biopsy (STB) technique that utilizes endoscopic submucosal dissection (ESD) for sampling SELs. However, unresolved advanced technical issues have hindered its widespread application. Currently, a counter-traction technique is used to facilitate ESD. We here describe a technically simplified STB technique using clip-with-line traction for gastric SELs.

A case of gastric heterotopic pancreas with gastroduodenal invagination

BACKGROUND

Heterotopic pancreas (HP) is a rare disease commonly found incidentally on imaging studies, at endoscopy or at autopsy and can be associated with abdominal pain, vomiting, heart burn, gastric outlet obstruction, and even dysphagia in very rare cases. Heinrich's classified HP into three groups, types1-3, with Heinrich's type 3 HP the rarest and difficult to diagnose properly because it has only pancreatic ducts but has no islet and acini. The aim of this study is to report a case of gastric outlet obstruction caused by type 3 HP with gastroduodenal invagination with reference to the literature and diagnosed finally by immuno-histochemical analysis.

CASE PRESENTATION

The case presented is a 40-year-old male presenting with vomiting and abdominal pain. Computed tomography (CT) revealed a cystic mass in the upper abdomen and he was referred to the Tokushima University. Gastric fiber showed that the pedunculated mass originated from the stomach. An open distal gastrectomy was performed. Pathologically, there was small glands proliferation in the sub-mucosal (SM) layer which was membrane and cytoplasm (MUC)1 positive and muscle proliferation.

RESULTS

This finding revealed the tumor as HP. Postoperative course was uneventful and the patient was discharged 12 days after surgery. The patient has remained well 12 months after surgery.

CONCLUSIONS

HP should be considered in the differential diagnosis of SM tumors with gastroduodenal invagination even if this is a rare symptom.

Heterotopic pancreas involved muscularis propria mimicking mesenchymal tumor in stomach

Heterotopic pancreas is defined as pancreatic tissue found outside the usual anatomic location of the pancreas. It is often an incidental finding and can be found at various sites in the gastrointestinal tract. It is usually asymptomatic, however, symptoms such as abdominal pain, nausea, vomiting or even gastrointestinal bleeding could be possible.

In this report, a 38-year-old woman with epigastric fullness and endoscopic impression of the gastric submucosal tumor is described. Preoperative surveys including endoscopic ultrasound and computed tomography suggested gastric mesenchymal tumor such as leiomyoma. A surgical operation was arranged with a diagnosis of the heterotopic pancreas as confirmed by pathological assessment.

Canalization technique to obtain deep tissue biopsy of gastrointestinal subepithelial tumors as an alternative to conventional known techniques

Background and Objectives

The most accurate technology to detect and diagnose subepithelial tumors (SETs) is the endoscopic ultrasonography (EUS) combined with puncture techniques, such as the endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) or the endoscopic ultrasonography-guided fine-needle biopsy. Going further in the improvement of the results of tumor samples obtained endoscopically to diagnose the SETs, the canalization technique guided by miniprobes (MPs) to obtain biopsies of SET could be an alternative to EUS-FNA. The objective of this study is to analyze the results of samples obtained by this procedure.

Materials and Methods

A multicenter, retrospective study of a review of a database of 32 consecutive patients with a SET in the digestive tract, from 2000 to 2015 was conducted. All patients underwent EUS-performed by MP, to define the size, internal echostructure, and layer of origin of tumor. Once the echostructure was defined, it proceeded to the canalization technique to arrive to the tumor tissue.

Results

The average diameter of SETs in this series (32 patients) was about 21.6±11 mm (range: 5-41 mm). The diagnostic accuracy was 28/32, 87.50% (Confidence interval 95%: 76.04%-98.99%), and there were no major complications. All procedures were performed on outpatients, none of which required additional hospitalization. The 50% of patients were operated or endoscopically resected and in all cases, the previous pathological diagnosis was confirmed.

Conclusions

This is a feasible, safe, and effective procedure that allows to access to inside of SET to obtain deep biopsies. Tumor samples obtained by deep biopsy, with prior performing of the canalization technique guided by MP, were sufficient for histopathological and immunohistochemical diagnosis and similar to those obtained with other known methods (FNA Trucut, ProCore^®, etc.). However, more prospective comparative studies with a larger number of patients and different specialists carrying out the procedure to reach a higher statistical significance are necessary.

Metastatic pancreatic cancer presenting as linitis plastica of the stomach

Metastatic disease from pancreatic carcinoma involving the stomach is an unusual event, and the pattern of spread in the form of linitis plastica, to our knowledge, has not been reported previously. Local recurrence after curative resection for pancreatic cancer is the most common pattern of disease. We report a case of metastatic pancreatic adenocarcinoma presenting as linitis plastica of the stomach 4 years after curative resection. A 52-year-old man presented with epigastric pain and melaena 4 years after undergoing a Whipple's procedure for a poorly-differentiated pancreatic adenocarcinoma, stage IB; T2N0M0. CT imaging of the abdomen revealed thickening of the gastric wall, and subsequent oesophagogastroduodenoscopy (OGD) revealed diffuse friable erythaematous tissue. The biopsy specimen obtained during the OGD revealed a poorly differentiated adenocarcinoma, with similar appearance to the prior specimen obtained from the pancreas.

Characteristic waffle-like appearance of gastric linitis plastica: A case report

Linitis plastica is a gastric cancer of diffuse histotype that presents in the fundic gland area, and is characterized by thickening of the stomach wall and deformation of the stomach, resulting in a leather bottle-like appearance. A 66-year-old female was admitted to Kagawa University Hospital (Kagawa, Japan) with epigastric pain. X-ray examination revealed reduced gastric distension and deformation of the stomach, which exhibited a leather bottle-like appearance. Endoscopy indicated a depressed lesion in the gastric antrum, and abnormal folds, which crossed to form a waffle-like appearance in the upper gastric body. Analysis of biopsy specimens from the depressed lesion revealed a poorly differentiated adenocarcinoma. Morphological changes in the gastric folds indicated that the tumor had invaded the upper gastric body, therefore, a total gastrectomy was performed. Subsequent pathological findings demonstrated that the tumor had spread from the primary lesion to the upper gastric body. Therefore, the present report recommends that the diagnosis of the spread of linitis plastica-type gastric cancer should include assessments of the primary lesion, as well as evaluation of morphological changes in the gastric folds.