A standardized pathology report for gastric cancer: 2nd edition

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements.The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Endoscopic Submucosal Dissection for Superficial Barrett’s Neoplasia in Korea: a Single-Center Experience

Purpose@#While the incidence of Barrett’s neoplasia has been increasing in Western countries, the disease remains rare in Asian countries. Therefore, very few studies have investigated the endoscopic treatment for Barrett’s neoplasia in Korea. Endoscopic submucosal dissection (ESD) enables en bloc and complete resection of gastrointestinal neoplastic lesions. This study aimed to evaluate the therapeutic outcomes of ESD for Barrett’s neoplasia in a single center in Korea and to examine the predictive factors for incomplete resection. @*Materials and Methods@#We conducted a retrospective observational study of 18 patients who underwent ESD for superficial Barrett’s neoplasia (dysplasia and early cancer) between January 2010 and December 2019 at Pusan National University Hospital. The therapeutic outcomes of ESD and procedure-related complications were analyzed. @*Results@#En bloc resection, complete resection, and curative resection were performed in 94%, 72%, and 61% of patients, respectively. Histopathology (submucosal or deeper invasion of the tumor) was a significant predictive factor for incomplete resection (P=0.047). Procedure-related bleeding and stenosis were not observed, whereas perforation occurred in one case. During the median follow-up period of 12 months (range, 6–74 months), local recurrence occurred in 2 patients with incomplete resection, one patient underwent repeat ESD, and the other patient received concurrent chemoradiotherapy. The 3-year overall and disease-specific survival rates were 73% and 93%, respectively. @*Conclusions@#ESD seems to be an effective and safe treatment for superficial Barrett’s neoplasia in Korea. Nevertheless, the suitability of ESD for Barrett’s cancer cases should be determined considering the high risk of deep submucosal invasion.

Clinicopathologic Features of Submucosal Papillary Gastric Cancer Differ from Those of Other Differentiated-Type Histologies

Background/Aims@#Papillary gastric cancer (GC) is classified as differentiated adenocarcinoma, together with well-differentiated (WD) and moderately differentiated (MD) adenocarcinoma. This study evaluated the risk of lymph node metastasis (LNM) in submucosal (SM) invasive papillary GC compared with other differentiated early GC types. @*Methods@#This retrospective study involved three tertiary hospitals and enrolled 1,798 lesions with differentiated SM invasive GC treated with curative gastrectomy between March 2001 and December 2012. All pathology slides were reviewed, and clinicopathologic findings associated with LNM, including tumor size, location, gross type, ulceration, depth and width of SM invasion, and lymphovascular invasion (LVI), were analyzed. @*Results@#The proportion of SM papillary GC was 2.8% (n=51). SM papillary GC was associated with larger tumor size and deeper and wider SM invasion than other differentiated GC types.LNM was significantly higher in the papillary type than in the MD and WD types. LNM was found in 27.5% of SM papillary GC patients (WD: 9.0%, MD: 21.2%). LVI was the only significant risk factor for LNM in SM papillary GC. The depth or width of SM invasion was not associated with LNM in papillary GC. Lower third location or elevated gross appearance was significantly associated with LVI. @*Conclusions@#SM papillary GC had the highest LNM rate, with features different from those of other differentiated SM invasive GCs. The treatment strategy for SM papillary GC should be carefully approached, especially for lesions located in the lower third or of the elevated gross type.

Standardization of the pathologic diagnosis of appendiceal mucinous neoplasms

Although the understanding of appendiceal mucinous neoplasms (AMNs) and their relationship with disseminated peritoneal mucinous disease have advanced, the diagnosis, classification, and treatment of AMNs are still confusing for pathologists and clinicians. The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists (GPSG-KSP) proposed a multicenter study and held a workshop for the “Standardization of the Pathologic Diagnosis of the Appendiceal Mucinous Neoplasm” to overcome the controversy and potential conflicts. The present article is focused on the diagnostic criteria, terminologies, tumor grading, pathologic staging, biologic behavior, treatment, and prognosis of AMNs and disseminated peritoneal mucinous disease. In addition, GPSG-KSP proposes a checklist of standard data elements of appendiceal epithelial neoplasms to standardize pathologic diagnosis. We hope the present article will provide pathologists with updated knowledge on how to handle and diagnose AMNs and disseminated peritoneal mucinous disease.

Histopathological Analysis of Esophageal Mucosa in Patients with Achalasia

Background/Aims@#Achalasia is an esophageal motor disorder that leads to functional esophageal obstruction. Food stasis and bacterial fermentation can predispose an individual to esophageal mucosal inflammation, causing multifocal dysplasia and increasing the risk of developing esophageal squamous cell carcinoma. We aimed to evaluate esophageal mucosal alterations in achalasia patients and determine clinical factors associated with the histopathological findings. @*Methods@#From 2009 to 2013, we obtained endoscopic biopsies from the lower and middle esophagus of 22 patients with achalasia and 17 controls. Patients’ clinical data and histological severity of esophagitis were retrospectively analyzed. Additionally, immunohistochemical staining for CD3, CD20, Ki-67, and p53 was conducted. @*Results@#The median age of achalasia patients was 49.5 years (range, 27 to 82 years), and there were nine males (40.9%). The median symptom duration was 5.8 years (range, 1 to 33.5 years), and 10 patients (45%) underwent previous treatment (nine, balloon dilation; one, botulinum toxin injection). Achalasia patients had significantly more severe esophagitis than did controls (p=0.001, lower esophagus; p=0.008, middle esophagus), and the number of CD3-positive lymphocytes exceeded that of CD20-positive lymphocytes (p<0.001). Achalasia patients also had a higher esophageal Ki-67 proliferation index (p=0.048). Although statistically nonsignificant, p53 expression was only observed in achalasia patients. There was no association between the histological severity of esophagitis and other clinicopathological findings. @*Conclusions@#Achalasia patients showed significantly severe histological esophagitis and a high Ki-67 proliferation index, indicating an increased risk of neoplastic progression. Therefore, careful endoscopic inspection is necessary for the early detection of superficial neoplasia in these patients.

Standardization of the pathologic diagnosis of appendiceal mucinous neoplasms

Although the understanding of appendiceal mucinous neoplasms (AMNs) and their relationship with disseminated peritoneal mucinous disease have advanced, the diagnosis, classification, and treatment of AMNs are still confusing for pathologists and clinicians. The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists (GPSG-KSP) proposed a multicenter study and held a workshop for the “Standardization of the Pathologic Diagnosis of the Appendiceal Mucinous Neoplasm” to overcome the controversy and potential conflicts. The present article is focused on the diagnostic criteria, terminologies, tumor grading, pathologic staging, biologic behavior, treatment, and prognosis of AMNs and disseminated peritoneal mucinous disease. In addition, GPSG-KSP proposes a checklist of standard data elements of appendiceal epithelial neoplasms to standardize pathologic diagnosis. We hope the present article will provide pathologists with updated knowledge on how to handle and diagnose AMNs and disseminated peritoneal mucinous disease.

Histopathological Analysis of Esophageal Mucosa in Patients with Achalasia

Background/Aims@#Achalasia is an esophageal motor disorder that leads to functional esophageal obstruction. Food stasis and bacterial fermentation can predispose an individual to esophageal mucosal inflammation, causing multifocal dysplasia and increasing the risk of developing esophageal squamous cell carcinoma. We aimed to evaluate esophageal mucosal alterations in achalasia patients and determine clinical factors associated with the histopathological findings. @*Methods@#From 2009 to 2013, we obtained endoscopic biopsies from the lower and middle esophagus of 22 patients with achalasia and 17 controls. Patients’ clinical data and histological severity of esophagitis were retrospectively analyzed. Additionally, immunohistochemical staining for CD3, CD20, Ki-67, and p53 was conducted. @*Results@#The median age of achalasia patients was 49.5 years (range, 27 to 82 years), and there were nine males (40.9%). The median symptom duration was 5.8 years (range, 1 to 33.5 years), and 10 patients (45%) underwent previous treatment (nine, balloon dilation; one, botulinum toxin injection). Achalasia patients had significantly more severe esophagitis than did controls (p=0.001, lower esophagus; p=0.008, middle esophagus), and the number of CD3-positive lymphocytes exceeded that of CD20-positive lymphocytes (p<0.001). Achalasia patients also had a higher esophageal Ki-67 proliferation index (p=0.048). Although statistically nonsignificant, p53 expression was only observed in achalasia patients. There was no association between the histological severity of esophagitis and other clinicopathological findings. @*Conclusions@#Achalasia patients showed significantly severe histological esophagitis and a high Ki-67 proliferation index, indicating an increased risk of neoplastic progression. Therefore, careful endoscopic inspection is necessary for the early detection of superficial neoplasia in these patients.

Histopathologic Diagnosis of Atrophic Gastritis and Intestinal Metaplasia

Atrophic gastritis and intestinal metaplasia are well-known to be reliable indicators of gastric cancer risk. They are clinically important in deciding whether to recommend endoscopic surveillance. Herein I review the histopathologic diagnosis of atrophic gastritis and IM. Gastric atrophy is divided into metaplastic atrophy and non-metaplastic atrophy. IM is categorized as complete (type I) and incomplete (type II, III). Systematic interpretation of gastric atrophy and IM using the updated Sydney system or operative link on gastritis assessment is recommended. Furthermore, I suggest using the consensus definition of gastric atrophy and incomplete IM in the gastric biopsy pathology report to support the surveillance of high-risk gastric cancer group.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the ‘Standardized Pathology Report for Colorectal Cancer,’ which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of “standard data elements” and “conditional data elements.” Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as “standard data elements,” while other prognostic factors and factors related to adjuvant therapy are classified as “conditional data elements” so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Pancreatic High-Grade Neuroendocrine Neoplasms in the Korean Population: A Multicenter Study / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The most recent 2017 World Health Organization (WHO) classification of pancreatic neuroendocrine neoplasms (PanNENs) has refined the three-tiered 2010 scheme by separating grade 3 pancreatic neuroendocrine tumors (G3 PanNETs) from poorly differentiated pancreatic neuroendocrine carcinomas (PanNECs). However, differentiating between G3 Pan- NETs and PanNECs is difficult in clinical practice. @*Materials and Methods@#Eighty-two surgically resected PanNENs were collected from 16 institutions and reclassified according to the 2017 WHO classification based on the histological features and proliferation index (mitosis and Ki-67). Immunohistochemical stains for ATRX, DAXX, retinoblastoma, p53, Smad4, p16, and MUC1 were performed for 15 high-grade PanNENs. @*Results@#Re-classification resulted in 20 G1 PanNETs (24%), 47 G2 PanNETs (57%), eight G3 well-differentiated PanNETs (10%), and seven poorly differentiated PanNECs (9%). PanNECs showed more frequent diffuse nuclear atypia, solid growth patterns and apoptosis, less frequent organoid growth and regular vascular patterns, and absence of low-grade PanNET components than PanNETs. The Ki-67 index was significantly higher in PanNEC (58.2%± 15.1%) compared to G3 PanNET (22.6%±6.1%, p < 0.001). Abnormal expression of any two of p53, p16, MUC1, and Smad4 could discriminate PanNECs from G3 PanNETs with 100% specificity and 87.5% sensitivity. @*Conclusion@#Histological features supporting the diagnosis of PanNECs over G3 PanNETs were the absence of a low-grade PanNET component in the tumor, the presence of diffuse marked nuclear atypia, solid growth pattern, frequent apoptosis and markedly increased proliferative activity with homogeneous Ki-67 labeling. Immunohistochemical stains for p53, p16, MUC1, and Smad4 may be helpful in distinguishing PanNECs from G3 PanNETs in histologically ambiguous cases, especially in diagnostic practice when only small biopsied tissues are available.

Inter-observer Reproducibility in the Pathologic Diagnosis of Gastric Intraepithelial Neoplasia and Early Carcinoma in Endoscopic Submucosal Dissection Specimens: A Multi-center Study / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The diagnostic criteria of gastric intraepithelial neoplasia (IEN) are controversial across the world. We investigated how many discrepancies occur in the pathologic diagnosis of IEN and early gastric carcinoma in endoscopic submucosal dissection (ESD) specimens, and evaluated the reasons of the discordance. MATERIALS AND METHODS: We retrospectively reviewed 1,202 ESD specimens that were originally diagnosed as gastric IEN and early carcinoma at 12 institutions. RESULTS: The final consensus diagnosis of carcinoma were 756 cases, which were originally 692 carcinomas (91.5%), 43 high-grade dysplasias (5.7%), 20 low-grade dysplasias (2.6%), and 1 others (0.1%), respectively. High- and low-grade dysplasia were finally made in 63 and 342 cases, respectively. The diagnostic concordance with the consensus diagnosis was the highest for carcinoma (91.5%), followed by low-grade dysplasia (86.3%), others (63.4%) and high-grade dysplasia (50.8%). The general kappa value was 0.83, indicating excellent concordance. The kappa values of individual institutions ranged from 0.74 to 1 and correlated with the proportion of carcinoma cases. The cases revised to a final diagnosis of carcinoma exhibited both architectural abnormalities and cytologic atypia. The main differential points between low- and high-grade dysplasias were the glandular distribution and glandular shape. Additional features such as the glandular axis, surface maturation, nuclear stratification and nuclear polarity were also important. CONCLUSION: The overall concordance of the diagnosis of gastric IEN and early carcinoma in ESD specimens was excellent. It correlated with the proportion of carcinoma cases, demonstrating that the diagnostic criteria for carcinoma are more reproducible than those for dysplasia.

A Rare Duodenal Subepithelial Tumor: Duodenal Schwannoma

Schwannomas are uncommon neoplasms that arise from Schwann cells of the neural sheath. Gastrointestinal schwannomas are rare among mesenchymal tumors of the gastrointestinal tract, and only a few cases have been reported to date. Duodenal schwannomas are usually discovered incidentally and achieving a preoperative diagnosis is difficult. Schwannomas can be distinguished from other subepithelial tumors on endoscopic ultrasonography; however, any typical endosonographic features of duodenal schwannomas have not been reported due to the rarity of these tumors. Immunohistochemistry is essential to distinguish schwannomas from gastrointestinal stromal tumors and leiomyomas. We report a case of duodenal schwannoma found incidentally during a health check-up endoscopy. On endoscopic ultrasonography, this tumor was suspected as a gastrointestinal stromal tumor; therefore, the patient underwent laparoscopic wedge resection of the tumor. Histopathology and immunohistochemistry confirmed that the duodenal lesion was a benign schwannoma.

Magnifying Endoscopy for Esophageal Ectopic Sebaceous Glands

Ectopic sebaceous glands are found very rarely in the esophagus; heretofore, several cases have been reported. The sebaceous gland is originally a source of an endodermal origin; however, there have been controversies regarding whether the origin of the esophageal ectopic sebaceous gland is ectodermal or endodermal. Ectopic sebaceous glands of the esophagus usually do not cause symptoms; thus, they are often found incidentally on endoscopy for routine health screening. Endoscopic findings are characterized by single or multiple yellow patches or nodular lesions of various sizes, sometimes with small central openings. We report two cases of esophageal ectopic sebaceous glands found incidentally during endoscopy with magnifying endoscopic findings. The lesions were in the mid-esophagus and lower esophagus, respectively, and both endoscopic findings were similar as multiple yellowish patches or plaques. Magnifying endoscopy revealed the openings of the excretory ducts surrounded by circular microvessels in both cases.

Case of an Inflammatory Myofibroblastic Tumor of the Duodenum / 대한소화기학회지

An inflammatory myofibroblastic tumor (IMT) is a rare disease that can occur in a variety of locations, including the lung, orbit, parotid, pleura, and stomach. Despite multiple reports in various organs, a duodenal IMT is rare with limited case reports. We encountered a case of a 49-year-old male with a duodenal IMT. The patient underwent a laparoscopic wedge resection under the impression of a duodenal mesenchymal tumor, such as gastrointestinal stromal tumor, but the final diagnosis was a duodenal IMT. The patient was treated successfully with an oral nonsteroidal anti-inflammatory drug for the residual lesions. He was free of recurrence during the 12 month follow-up period.

Case of Bleeding Ileal Varices after a Colectomy Diagnosed by Capsule Endoscopy / 대한소화기학회지

We report a case of bleeding ileal varices associated with intra-abdominal adhesions after colectomy which was successfully diagnosed using capsule endoscopy. A 77-year-old woman visited the emergency department for several episodes of melena. She had a medical history of neoadjuvant chemo-radiation therapy and subsequent surgery for rectal cancer 6 years previously. Conventional diagnostic examinations including upper endoscopy, colonoscopy, and abdominal computed tomography could not detect any bleeding focus, however, following capsule endoscopy revealed venous dilatations with some fresh blood in the distal ileum, indicating bleeding ileal varices. The patient underwent exploratory laparotomy and the affected ileum was successfully resected. No further gastrointestinal bleeding occurred during the 6 months follow-up. Small intestinal varices are important differential for obscure gastrointestinal bleeding especially in patients with a history of abdominal surgery in the absence of liver cirrhosis, and capsule endoscopy can be a good option for diagnosing small intestinal varices.

A Case of Duodenal Ganglioneuroma Manifesting as a Subepithelial Tumor

Ganglioneuroma of the gastrointestinal tract is a rare tumor that consists of ganglion cells, nerve fibers, and supporting cells of the enteric nervous system. Ganglioneuromas are usually associated with genetic disorders such as the multiple endocrine neoplasia syndrome or neurofibromatosis. Ganglioneuromas of the gastrointestinal tract predominantly involve the colon and rectum, and reports about duodenal ganglioneuromas are few. Herein, we report a case of duodenal ganglioneuroma treated with endoscopic resection. A 56-year-old female patient visited our hospital because of a subepithelial tumor in the second portion of the duodenum. She had no remarkable medical or family history and revealed no history of genetic disorders. Endoscopic ultrasonography and abdominal computed tomography revealed a tumor located mainly in the submucosal layer, without any regional lymph node involvement. Endoscopic resection of the lesion was performed, and the pathological examination confirmed a duodenal ganglioneuroma.

A Case of Anticoagulant-induced Spontaneous Intramural Intestinal Hematoma

Spontaneous intramural hematoma is a rare complication of oral anticoagulants, and its incidence is expected to increase because of the increasing number of elderly patients undergoing anticoagulant therapy. Clinical manifestations of spontaneous intramural hematoma vary from mild abdominal pain to intestinal obstruction or acute abdomen. Early diagnosis is important because most patients can be treated successfully without surgery. The role of endoscopy in the diagnosis of intramural hematoma is not well established because almost all cases are diagnosed non-invasively with computed tomography scans. However, confirmation of the intramural hematoma through direct visualization of the involved bowel mucosa is helpful, if the imaging diagnosis is uncertain. We report a case of anticoagulant-induced spontaneous intramural hematoma, which was diagnosed using endoscopy, with relevant literature review.

Negative Histology after Endoscopic Resection: A Pathologist's Aspect / 대한Helicobacter연구학회지

Endoscopic biopsy is the most popular diagnostic procedure for gastric epithelial neoplasm. However, discrepancy between biopsy and endoscopic resection diagnosis occasionally occurs and leads to an unnecessary procedure. A negative pathologic diagnosis following endoscopic resection is particularly problematic. In this context, we reviewed factors that may be associated with a diagnostic discrepancy between endoscopic biopsy and endoscopic resection, with focus on crypt dysplasia.

A Rare Case of Early Gastric Cancer Combined with Underlying Heterotopic Pancreas

Heterotopic pancreas in the stomach is usually asymptomatic and benign. Here, we presented a rare case of an early gastric cancer overlying a heterotopic pancreas. A 48-year-old woman underwent esophagogastroduodenoscopy, which revealed a subepithelial mass measuring 2.0×1.5 cm on the gastric antrum with a 1-cm erosive erythematous discoloration on the surface. A biopsy specimen showed moderately differentiated tubular adenocarcinoma. Endosonography showed a heterogeneous hypoechoic mass measuring 1.3×0.6 cm, with indistinct margins in the second and third layers of the gastric wall; anechoic tubular structures within the mass were suggestive of heterotopic pancreas. Distal gastrectomy was performed, which confirmed an early gastric cancer confined to the mucosa, and a separate underlying heterotopic pancreas. Although heterotopic pancreas is most likely benign, careful endoscopic observation of the mucosal surface is necessary to avoid overlooking a coincident early gastric cancer.