Comparison of the Diagnostic Ability of Endoscopic Ultrasonography and Abdominopelvic Computed Tomography in the Diagnosis of Gastric Subepithelial Tumors

BACKGROUND/AIMS: Endoscopic ultrasonography (EUS) is the most efficient imaging modality for gastric subepithelial tumors (SETs). However, abdominopelvic computed tomography (APCT) has other advantages in evaluating the characteristics, local extension, or invasion of SETs to adjacent organs. This study aimed to compare the diagnostic ability of EUS and APCT based on surgical histopathology results.METHODS: We retrospectively reviewed data from 53 patients who underwent both EUS and APCT before laparoscopic wedge resection for gastric SETs from January 2010 to December 2017 at a single institution. On the basis of histopathology results, we assessed the diagnostic ability of the 2 tests.RESULTS: The overall accuracy of EUS and APCT was 64.2% and 50.9%, respectively. In particular, the accuracy of EUS vs. APCT for the diagnosis of gastrointestinal stromal tumors (GISTs), leiomyomas, and ectopic pancreas was 83.9% vs. 74.2%, 37.5% vs. 0.0%, and 57.1% vs. 14.3%, respectively. Most of the incorrect diagnoses with EUS involved hypoechoic lesions originating in the fourth echolayer, with the most common misdiagnosed lesions being GISTs mistaken for leiomyomas and vice versa.CONCLUSIONS: APCT showed a lower overall accuracy than EUS; however, APCT remains a useful modality for malignant/potentially malignant gastric SETs.

Primary Gastric Small Cell Carcinoma: A Case Identified as a Large Subepithelial Tumor from Invisible State in 6 Months

Primary gastric small cell carcinoma (GSCC) is one of the gastroenteropancreatic neuroendocrine tumors. It is a rare cancer with a very aggressive behavior and a poor prognosis because of the high rate of metastases. It is usually found in far advanced stage. We experienced a case of GSCC which had developed into a large subepithelial tumor (SET) from invisible state in a short period. A 65-year-old man consulted our hospital because of early gastric cancer. He underwent endoscopic submucosal dissection for the early gastric cancer at high body posterior wall. After 6 months, the follow-up endoscopy showed a large newly developed SET-like lesion with central ulceration at the gastric cardia. Endoscopic biopsy revealed GSCC. Total gastrectomy was performed. One out of the 26 perigastric lymph nodes had a metastasis. He received 6 cycles of adjuvant chemotherapy with etoposide and cisplatin. He is still in good health 12 months after operation.

Current Status of Endoscopic Ultrasonography in Gastrointestinal Subepithelial Tumors

Gastrointestinal subepithelial tumors (GSTs) are usually detected incidentally on endoscopic or radiologic examinations. In conventional endoscopy, a GST usually presents as a protuberant lesion with an intact mucosal surface. As the lesion is located beneath the mucosal layer of the gastrointestinal tract, conventional biopsy typically does not reveal the pathologic diagnosis. First, a GST should be differentiated from an extrinsic compression through the positional change of the patient during conventional endoscopic examination. In cases of GSTs originating from the gastrointestinal wall, endoscopic ultrasonography (EUS) can be beneficial for narrowing the differential diagnosis through delineation of echo findings and by determining the layer of origin. EUS findings can also help determine the management strategies for GSTs by making a differential diagnosis according to malignant potential.

Contrast Enhanced Endoscopic Ultrasound Imaging for Gastrointestinal Subepithelial Tumors

Subepithelial tumors are divided into benign subepithelial and potentially malignant gastrointestinal stromal tumors. It is difficult to distinguish between these tumor types. Contrast-enhanced harmonic endoscopic ultrasound is reportedly useful for diagnosing subepithelial tumors, can be safely and easily performed by understanding the principle and method, and can be used to distinguish between tumor types with high sensitivity on the basis of differences in contrast effect. The generated image shows a hyper-enhancement pattern in gastrointestinal stromal tumors (sensitivity, 78%–100%; specificity, 60%–100%; accuracy, 60%–100%) and hypo-enhancement pattern in benign subepithelial tumors. Contrast-enhanced harmonic endoscopic ultrasound can be used to estimate the malignancy potential of gastrointestinal stromal tumors by evaluating the uniformity of the contrast and the blood vessels inside the tumor, with abnormal intra-tumor blood vessels, heterogeneous enhancement, and non-enhancing spots suggesting malignancy. Contrast-enhanced harmonic endoscopic ultrasound has a higher sensitivity than other imaging modalities for the detection of vascularity within gastrointestinal stromal tumors. Additionally, it has been reported that treatment effects can be estimated by evaluating the blood flow in the gastrointestinal stromal tumor before and after treatment with tyrosine kinase inhibitors using contrast-enhanced ultrasound. However, there will be subjective-bias and the results depends on the performer’s skill.

Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy in Gastrointestinal Subepithelial Tumors

The incidence of asymptomatic and incidentally found upper gastrointestinal subepithelial tumors (SETs) is increasing with the implementation of national cancer screening and the development of high-resolution endoscopy in Korea. However, endoscopy alone cannot be used to determine whether SETs are benign or malignant. Endoscopic ultrasound (EUS) is used to further characterize these lesions through the examination of their layered structure, internal echogenicity, size, and relationship to the extramural structure. These provide additional information on whether the lesion is benign or malignant. Nevertheless, the sensitivity and specificity of EUS alone in predicting malignancy is unsatisfactory. Recent guidelines have recommended deciding the timing of EUS-fine needle aspiration and biopsy (EUS-FNA/B) for SETs based on tumor size, malignant features on endoscopy, and high-risk features on EUS. The diagnostic accuracy of EUS-FNA/B is reportedly influenced by factors including needle size, number of needle passes, use of suction, use of a stylet in the needle assembly, fanning technique, availability of an on-site cytopathologist, and experience of the endosonographer. Therefore, according to the characteristics of the SETs, various subsequent methods and techniques should be appropriately employed to improve the diagnostic yield of EUS-FNA/B.

Early Phase of Achalasia Manifested as an Esophageal Subepithelial Tumor / 대한소화기학회지

The Chicago classification (CC) defines an esophagogastric junction outflow obstruction (EGJOO) as the presence of several instances of intact or weak peristalsis, elevated median integrated relaxation pressure above 15 mmHg, and a discrepancy from the criteria of achalasia. The revised CC addresses the potential etiology of EGJOO, including the early forms of achalasia, mechanical obstruction, esophageal wall stiffness, or manifestation of hiatal hernia. A 58-year-old woman visited the Presbyterian Medical Center with swallowing difficulty. The patient underwent a high resolution manometry (HRM) examination and was diagnosed with EGJOO. Chest CT was performed to exclude a mechanical obstruction as a cause, and CT revealed a subepithelial tumor (SET) at the upper part of the esophagogastric junction. Therefore, laparoscopic surgery was performed and eccentric muscular hypertrophy of the distal esophagus was observed. Longitudinal myotomy and Dor fundoplication were also performed. The histology findings of the surgical specimens were consistent with achalasia. This paper reports a case of early achalasia that was finally diagnosed by the histology findings, but was initially diagnosed as EGJOO using HRM and misdiagnosed as SET in the image study.

Early Phase of Achalasia Manifested as an Esophageal Subepithelial Tumor / 대한소화기학회지

The Chicago classification (CC) defines an esophagogastric junction outflow obstruction (EGJOO) as the presence of several instances of intact or weak peristalsis, elevated median integrated relaxation pressure above 15 mmHg, and a discrepancy from the criteria of achalasia. The revised CC addresses the potential etiology of EGJOO, including the early forms of achalasia, mechanical obstruction, esophageal wall stiffness, or manifestation of hiatal hernia. A 58-year-old woman visited the Presbyterian Medical Center with swallowing difficulty. The patient underwent a high resolution manometry (HRM) examination and was diagnosed with EGJOO. Chest CT was performed to exclude a mechanical obstruction as a cause, and CT revealed a subepithelial tumor (SET) at the upper part of the esophagogastric junction. Therefore, laparoscopic surgery was performed and eccentric muscular hypertrophy of the distal esophagus was observed. Longitudinal myotomy and Dor fundoplication were also performed. The histology findings of the surgical specimens were consistent with achalasia. This paper reports a case of early achalasia that was finally diagnosed by the histology findings, but was initially diagnosed as EGJOO using HRM and misdiagnosed as SET in the image study.

Endoscopic Resection of Xanthogranulomatous Gastritis Presenting as a Subepithelial Tumor: A Case Report

Xanthogranulomatous gastritis (XGG) presenting as a subepithelial tumor (SET) is a very rare entity. We report a case of SET-like XGG diagnosed and treated with endoscopic resection. A 55-year-old female patient was initially referred with a 1.5-cm SET located at the anterior wall of the middle antrum. Endoscopic ultrasound examination revealed submucosal invasion without any perigastric lymph node enlargement. Endoscopic resection was performed for an accurate diagnosis and treatment, and the lesion was diagnosed histopathologically as XGG. At the 18-month follow-up after endoscopic resection, there was no evidence of XGG recurrence. SET-like XGG is very rare and the diagnosis is a preoperative challenge. However, inflammatory tumors should be considered in the differential diagnosis of SET

Lymphangioma of the Esophagus

Lymphangioma of the esophagus is a rare submucosal benign tumor. A 49-year-old man was referred because of a foreign body sensation in the esophagus. In endoscopy, a 10.0×1.0-cm longitudinal, translucent, whitish yellow mass covered with normal esophageal mucosa was found in the lower esophagus. Endoscopic ultrasonography revealed a heterogeneous, mainly hypoechoic, well-circumscribed lesion located in the third layer. Incisional biopsy was performed, and histologic findings showed multiple dilated lymphatic vessels, consistent with lymphangioma. After 3 months of proton pump inhibitor treatment, the symptom was relieved and the patient is currently asymptomatic and under surveillance.

Tuberculous Lymphadenitis Mimicking Gastric Subepithelial Tumor Diagnosed Using Endoscopic Ultrasound-guided Fine-needle Aspiration

A gastric subepithelial tumor (SET) is commonly detected during a diagnostic endoscopic examination. Gastric tuberculosis (TB), in particular, can present as a SET of the gastric wall. A few cases of gastric TB mimicking a SET have recently been reported. Radiological imaging combined with endoscopic biopsy can aid in the early diagnosis of TB without surgical intervention. A 41-year-old man visited our health promotion center for a regular check-up. Esophagogastroduodenoscopy (EGD) revealed a round and smooth, bulging mucosal lesion suggesting a gastric SET in the upper body of the stomach. Endoscopic ultrasound (EUS) demonstrated a hypoechoic lesion measuring 18 mm, with an obscure layer of origin, and EUS-guided fine-needle aspiration was performed. Microscopic examination of the sample showed chronic granulomatous inflammation. Histopathologically, the aspirated sample showed positive Ziehl-Neelsen staining, confirming a diagnosis of tuberculous lymphadenitis. We describe a case of a patient who presented with tuberculous lymphadenitis mimicking a SET of the stomach. The lesion was found on EGD and confirmed using EUS-guided fine-needle aspiration.

Primary Follicular Lymphoma in the Rectum Incidentally Found on Screening Colonoscopy / 대한소화기학회지

The gastrointestinal tract is the most common site of extra-nodal non-Hodgkin lymphoma. However, the incidence of primary rectal lymphoma is extremely rare. Among the primary gastrointestinal lymphomas, follicular lymphoma has been described as a rare disease. It is difficult to diagnose rectal lymphoma due to its variable growth patterns and inadequate biopsies. Majority of patients with rectal lymphoma have non-specific symptoms or negative biopsies, often delaying the diagnosis. Our patient is a 62-year-old female. Two sessile and smooth subepithelial lesions with a yellowish normal mucosa were found on a screening colonoscopy. The initial mucosal biopsy finding was chronic inflammation, but we were highly suspicion of malignancy; we performed an endoscopic mucosal resection. Herein, we present a rare case of rectal follicular lymphoma diagnosed by endoscopic mucosal resection with a literature review.

Esophageal Squamous Cell Carcinoma Presenting as a Subepithelial Tumor

Esophageal squamous cell carcinoma (ESCC) presenting as subepithelial tumor-like growth is a very rare form of the disease. We report a case of primary ESCC with intramural growth, covered with normal esophageal epithelium. The patient was initially referred due to a subepithelial tumor at the mid-esophagus, butendoscopic ultrasonography revealed a heterogeneously hypoechoic mass, which disrupted the structure of the muscularis propria. An endoscopic submucosal dissection was performed for accurate diagnosis, and the lesion was diagnosed histopathologically as moderately differentiated squamous cell carcinoma. Computed tomography revealed an enlarged left upper paratracheal lymph node, which showed increased uptake on positron emission tomography. The patient underwent subtotal esophagectomy with total mediastinal lymphadenectomy and adjuvant chemotherapy. Primary ESCC with intramural growth is extremely rare. For accurate diagnosis, when there is a high index of suspicion, additional investigations such as endoscopic ultrasonography or diagnostic endoscopic submucosal dissection might be needed.

Using Forceps Biopsy after Small Submucosal Dissection in the Diagnosis of Gastric Subepithelial Tumors

The current tissue sampling techniques for subepithelial tumors (SETs) of the gastrointestinal (GI) tract have limited diagnostic efficacy. We evaluated the diagnostic yield and safety of forceps biopsies after small endoscopic submucosal dissection (SESD biopsies) in the diagnosis of gastric SETs. A total of 42 patients with gastric SETs > 10 mm were prospectively enrolled between May 2013 and October 2014. A dual knife was used to incise the mucosa and submucosa and forceps biopsies were then introduced deep into the lesion. To compare SESD biopsies with EUS-FNA, we used the retrospective data of 30 EUS-FNA cases. The diagnostic yield of SESD biopsies was comparable to that of EUS-FNA (35/42, 83.3% vs. 24/30, 80.0%, P = 0.717). The mean procedure time of SESD biopsies was shorter than that of EUS-FNA (10 vs. 37 minutes, P < 0.001). There were no procedure-related adverse events in the both group. The pathological diagnoses in SESD biopsies group included 15 leiomyomas, 7 GISTs, 10 heterotopic pancreases, 2 lipomas, and one other lesion. SESD biopsies are an easy, effective and safe technique for the diagnosis of gastric SETs and its diagnostic yield is comparable to that of EUS-FNA. This technique may be a reliable alternative to conventional EUS-FNA (Clinical trial registration No. KCT0000730).

Endoscopic Full-thickness Resection for Gastric Tumor

Endoscopic full-thickness resection (EFTR) is a natural orifice transluminal endoscopic surgery (NOTES) that was developed to overcome the limitations of laparoscopic resection and conventional endoscopic resection methods (endoscopic mucosal resection and endoscopic submucosal dissection). EFTR can be performed with endoscopy only or combined with a laparoscopic approach. During EFTR, the lesions can be exposed to peritoneum or not. Laparoscopic and endoscopic cooperative surgery (LECS) is a well-known procedure in which the lesion is exposed to peritoneum. Non-exposed endoscopic wall-inversion surgery (NEWS) and simple non-exposure EFTR were developed to escape the exposure of the lesions to peritoneum. Submucosal tunneling method may be a good candidate for treatment of subepithelial tumors at the esophagogasric junction and gastric cardia. This review will give an overview about current EFTR techniques to treat subepithelial tumors and adenocarcinoma of stomach.

Advances in the Management of Upper Gastrointestinal Subepithelial Tumor: Pathologic Diagnosis Using Endoscopy without Endoscopic Ultrasound-Guided Biopsy

Until now, biopsy methods for subepithelial tumors (SETs) have focused on endoscopic ultrasound (EUS)-guided biopsy; however, these methods have several limitations. We devised a simple method for pathologic diagnosis of SETs. SETs are occasionally diagnosed during endoscopy, and lesions are generally small and asymptomatic. It can be challenging to decide on a management plan for large asymptomatic SETs. EUS imaging provides information regarding the size, layer, and echo pattern of the lesions. Patient management plans have traditionally been determined based on EUS images, whereby the endoscopist chooses to either monitor or remove the tumor. However, EUS alone cannot diagnose and evaluate upper gastrointestinal SETs with high accuracy. As sufficient tissue samples are required for the accurate diagnosis of SETs, EUS-guided biopsy techniques such as EUS fine-needle aspiration and trucut biopsy are currently used. However, these methods have a relatively low diagnostic accuracy and do not always provide information upon immunohistochemical staining. Endoscopists can easily detect a submucosal mass after creating an iatrogenic mucosal ulcer, after which tissue sampling is performed by using endoscopic biopsy. Furthermore, pathologic results can differentiate between benign and premalignant lesions. Here, we introduce a simple method for the pathologic diagnosis of SETs.

Role of Endoscopic Ultrasonography in Guiding Treatment Plans for Upper Gastrointestinal Subepithelial Tumors

Gastrointestinal (GI) subepithelial tumors (SETs) are usually observed incidentally by endoscopy and have diverse prognoses, varying from benign to potentially malignant. When a GI SET is suspected, endoscopic ultrasonography (EUS) is the most accurate diagnostic method to differentiate it from extraluminal compression. To determine the nature of GI SETs, EUS is also the most accurate diagnostic method, and reveals the precise sonographic nature of the lesion. There are some SETs with typical EUS findings of GI SETs, but most hypoechoic lesions are difficult to diagnose based on EUS images alone. EUS is also helpful to determine GI wall involvement in SETs and optimal treatment methods. For the diagnosis of GI SETs, obtaining a proper specimen is essential. EUS-guided cytology or biopsy methods such as fine-needle aspiration, Tru-Cut biopsy, and the newly introduced fine-needle biopsy (FNB) provide good results. To increase the diagnostic yield for GI SETs, cytology with immunocytochemical staining is used for cytological interpretation, resulting in good diagnostic yields. Recently, EUS-FNB using cheese slicer technology has been introduced, and has been reported to provide good diagnostic results for GI SETs.

Long-Term Outcomes after Endoscopic Treatment of Gastric Gastrointestinal Stromal Tumor

Endoscopic resection of gastric subepithelial tumors (SETs) has several advantages over biopsy techniques, such as superior diagnostic yield and definite diagnosis. Removal of gastric SETs and histopathologic confirmation should be considered whenever gastric SETs are highly suspected to have malignant potential such as gastrointestinal stromal tumor (GIST) or neuroendocrine tumor. According to our clinical experience, we suggest that endoscopic resection of gastric SETs is feasible for GISTs less than 3.0 cm without positive endoscopic ultrasonography findings or for hypoechoic SETs less than 3.0 cm. However, serious complications such as macroperforation may occur during endoscopic resection, and this procedure is highly dependent on endoscopists' skills. We recently reported the long-term clinical outcomes of endoscopic resection of gastric GIST, which showed a relatively low recurrence rate (2.2%) during long-term follow-up (46.0±28.5 months) despite the low R0 resection rate (25.0%). We suggest that endoscopic surveillance might be possible without additional surgical resection in completely resected GISTs without residual tumor confirmed to be lower risk, even if they show an R1 resection margin.

Endoscopic Treatment of Gastric Subepithelial Tumor

Most of subepithelial tumor (SET) in stomach is incidentally found during esophagogastroduodenoscpic examination. Even small gastric SETs less than 2.0 cm might have malignant potential, thus ambiguous cases should be removed and pathologically confirmed for optimal diagnosis and treatment. As endoscopic techniques are developed, endoscopic removal of gastric SETs has been reported increasingly. The endoscopic procedures for resection of gastric SETs include classic methods such as snare polypectomy or incisional enucleation, and more progressive and standard technique such as endoscopic submucosal dissection. For gastric SETs originated from deeper layer including muscularis mucosa, novel procedures such as endoscopic submucosal tunnel dissection and endoscopic full-thickness resection (EFTR) are now being introduced, and cooperation with laparoscopic approach such as laparoscopy- assisted EFTR might be an alternative option to overcome shortcomings of endoscopic procedures only and ensure more safe and complete resection.

Diffuse Ganglioneuromatosis of the Colon Presenting as a Large Subepithelial Tumor in Adults: Report of Two Cases / 대한소화기학회지

Colonic diffuse ganglioneuromatosis is a benign neoplastic condition characterized by disseminated, intramural, or transmural proliferation of neural elements involving the enteric plexuses, sometimes associated with von Recklinghausen's disease and other multiple tumor syndromes. Colonic diffuse ganglioneuromatosis is usually large, ranging from 1 to 17 cm, and thus can distort the surrounding tissue architecture as well as infiltrate the adjacent bowel wall. However, colonic diffuse ganglioneuromatosis is an exceptional finding in adults and only individual cases are reported in the literature. Herein, we report two unusual cases of adult patients with colonic diffuse transmural ganglioneuromatosis presenting as a large subepithelial tumor.

Natural Course of Gastric Subepithelial Tumor

Subepithelial tumor (SET) is a protruding elevated mass covered with normal appearing mucosa, and is a relatively common finding during esophagogastroduodenoscopy. Recently, the incidence of asymptomatic small SETs is increasing due to esophagogastroduodenoscopy for national gastric cancer screening program in Korea. Unfortunately, the management of SETs is still controversial because the natural history of SETs is hardly known. There are only few studies about the natural history of SETs, especially in the stomach. According to studies, the overall rate of increased size of gastric SETs is 5.4~28%. Tumor size, age, non-upper area of the stomach, and detection of anechoic lesion or echogenic foci on endoscopic ultrasound (EUS) are related with size increase in gastric SETs. Gastrointestinal stromal tumors (GISTs) are one of the most important tumors, and the prognosis of GISTs is closely connected with tumor size, mitotic count, and organ location. Among them, tumor size is relatively easy to approach with esophagogastroduodenoscopy or EUS. Asymptomatic gastric SETs 2 cm, < or =5 cm might be considered for detailed pathologic diagnosis and treatment, if the possibility of GISTs cannot be ruled out. Well-designed, prospective studies are required for more accurate management of SETs.