Tuberculosis of Cystic Duct Lymph Node Associated with Cholecystitis / 대한소화기학회지

Tuberculosis of the cystic duct lymph node is very rare. Only four cases have been reported in the literature. This paper presents the case of a young male patient with a tuberculous cystic duct lymph node and chronic cholecystitis, who was diagnosed with cystic duct stones and a gall bladder polyp preoperatively.

Paget's Disease of Bone Affecting Peripheral Limb: Difficulties in Diagnosis: A Case Report

In terms of management of Paget's disease of bone (PDB), early diagnosis and proper management achieving remission is essential with lifelong specialist follow-up. We present the case of a 40-year-old woman with PDB affecting mainly the distal extremities (ankle and wrist). The patient visited our hospital in 2012 with heel pain. Plain radiography revealed osteoporosis, and a bone scan revealed hot uptake. Initial laboratory investigations showed normal serum calcium, 25-hydroxy-vitamin D, and parathyroid hormone levels; however, osteocalcin, C-terminal telopeptide of type I collagen, and bone alkaline phosphatase levels were elevated. A bone mineral density scan showed T- and Z-scores of −2.5 and −2.7, respectively, and bisphosphonate treatment was initiated. Biopsy performed on the calcaneal lateral wall revealed inconclusive findings. Follow-up biopsy on the left distal radius was performed 7 years later to investigate wrist pain, and this examination led to a final diagnosis as PDB. We suggest inconclusive biopsy result during the early phase of PDB and highly recommend follow-up evaluation in osteoporosis with atypical behavior.

A scoring system for the diagnosis of non-alcoholic steatohepatitis from liver biopsy

Background@#Liver biopsy is the essential method to diagnose non-alcoholic steatohepatitis (NASH), but histological features of NASH are too subjective to achieve reproducible diagnoses in early stages of disease. We aimed to identify the key histological features of NASH and devise a scoring model for diagnosis. @*Methods@#Thirteen pathologists blindly assessed 12 histological factors and final histological diagnoses (‘not-NASH,’ ‘borderline,’ and ‘NASH’) of 31 liver biopsies that were diagnosed as non-alcoholic fatty liver disease (NAFLD) or NASH before and after consensus. The main histological parameters to diagnose NASH were selected based on histological diagnoses and the diagnostic accuracy and agreement of 12 scoring models were compared for final diagnosis and the NAFLD Activity Score (NAS) system. @*Results@#Inter-observer agreement of final diagnosis was fair (κ = 0.25) before consensus and slightly improved after consensus (κ = 0.33). Steatosis at more than 5% was the essential parameter for diagnosis. Major diagnostic factors for diagnosis were fibrosis except 1C grade and presence of ballooned cells. Minor diagnostic factors were lobular inflammation ( ≥ 2 foci/ × 200 field), microgranuloma, and glycogenated nuclei. All 12 models showed higher inter-observer agreement rates than NAS and post-consensus diagnosis (κ = 0.52–0.69 vs. 0.33). Considering the reproducibility of factors and practicability of the model, summation of the scores of major (× 2) and minor factors may be used for the practical diagnosis of NASH. @*Conclusions@#A scoring system for the diagnosis of NAFLD would be helpful as guidelines for pathologists and clinicians by improving the reproducibility of histological diagnosis of NAFLD.

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.

Angiomyolipoma of the Liver without a Fat Component, Mimicking a Hepatocellular Carcinoma / 대한소화기학회지

Angiomyolipoma (AML) is a rare benign mesenchymal tumor in the liver, which is composed of blood vessels, smooth muscle, and adipose cells. The proportion of each component varies, making a diagnosis difficult. This paper reports a case of AML in the liver without adipose tissue, mimicking a hepatocellular carcinoma (HCC), which was diagnosed by a surgical tissue biopsy. A 65-year-old woman was admitted for an evaluation of a hepatic mass that had been detected by ultrasonography. The serologic markers of viral hepatitis B and C were negative. The liver function tests and alpha fetoprotein level were within the normal limits. Magnetic resonance imaging revealed a 1.9 cm sized mass in segment 6 of the liver with early arterial enhancement and washout on the delayed phase accompanied by a rim-like enhancement, which is similar to the imaging findings of HCC. A frozen section examination during surgery indicated a hepatocellular neoplasm and suggested the possibility of HCC. On the other hand, the final pathologic diagnosis was epithelioid myoid type of AML with no adipose tissue component. The tumor cells were positive for human melanocyte B-45 and negative for cytokeratin and hepatocyte paraffin 1. This paper reports a very rare case of AML without adipose tissue in the liver mimicking HCC that was diagnosed by a surgical tissue biopsy.

Rare Form of Schwannoma as a Purely Hemorrhagic Cystic Tumor Located in an Intermuscular Plane

Schwannomas are mostly solid tumors, some of which may contain cystic degenerations or hemorrhages. However, a schwannoma seen as a purely hemorrhagic cystic tumor is very rare. A 63-year-old woman was referred to the hospital due to a slow-growing mass (present for about 5 years) on her right thigh. She complained about vague pain but without neurologic symptoms such as numbness or tingling sensations. MR images showed an oval lesion with defined margins surrounded by the rectus femoris, vastus lateral, and the vastus intermedius. It was characterized as a multilocular cystic lesion composed of hemorrhagic fluid. In addition, the benign hemorrhagic cystic lesion was differentially diagnosed by radiological techniques as a hemorrhagic ganglion cyst. The lesion was surgically excised and, based on pathological features, was diagnosed as being a schwannoma. We report a purely hemorrhagic cystic schwannoma located in an intermuscular plane.

Rare Form of Rheumatoid Nodule around Ischial Tuberosity Mimicking Ischiogluteal Bursitis

We are reporting about a case of a rheumatoid nodule, beneath the ischial tuberosity, mimicking ischiogluteal bursitis. Rheumatoid nodules are frequently seen, at the subcutaneous soft tissues of repetitive mechanical irritation points, and prominent bones. There have been no reported cases of rheumatoid nodules, extending just beneath the ischial tuberosity bone. A 68-year-old woman with a seven-year history of rheumatoid arthritis, suffered for six months, from right buttock swelling and discomfort in seating. A cystic lesion postero-inferior to the ischial tuberosity, was noted in the MRI scan, which was thought to be ischiogluteal bursitis, because of its characteristic location and appearance. Histopathologic analysis and gross findings on the operation, revealed no evidence of bursitis.

Rare Form of Rheumatoid Nodule around Ischial Tuberosity Mimicking Ischiogluteal Bursitis

We are reporting about a case of a rheumatoid nodule, beneath the ischial tuberosity, mimicking ischiogluteal bursitis. Rheumatoid nodules are frequently seen, at the subcutaneous soft tissues of repetitive mechanical irritation points, and prominent bones. There have been no reported cases of rheumatoid nodules, extending just beneath the ischial tuberosity bone. A 68-year-old woman with a seven-year history of rheumatoid arthritis, suffered for six months, from right buttock swelling and discomfort in seating. A cystic lesion postero-inferior to the ischial tuberosity, was noted in the MRI scan, which was thought to be ischiogluteal bursitis, because of its characteristic location and appearance. Histopathologic analysis and gross findings on the operation, revealed no evidence of bursitis.

Interobserver Agreement on Pathologic Features of Liver Biopsy Tissue in Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND: The histomorphologic criteria for the pathological features of liver tissue from patients with non-alcoholic fatty liver disease (NAFLD) remain subjective, causing confusion among pathologists and clinicians. In this report, we studied interobserver agreement of NAFLD pathologic features and analyzed causes of disagreement. METHODS: Thirty-one cases of clinicopathologically diagnosed NAFLD from 10 hospitals were selected. One hematoxylin and eosin and one Masson's trichrome-stained virtual slide from each case were blindly reviewed with regard to 12 histological parameters by 13 pathologists in a gastrointestinal study group of the Korean Society of Pathologists. After the first review, we analyzed the causes of disagreement and defined detailed morphological criteria. The glass slides from each case were reviewed a second time after a consensus meeting. The degree of interobserver agreement was determined by multi-rater kappa statistics. RESULTS: Kappa values of the first review ranged from 0.0091-0.7618. Acidophilic bodies (k = 0.7618) and portal inflammation (k = 0.5914) showed high levels of agreement, whereas microgranuloma (k = 0.0984) and microvesicular fatty change (k = 0.0091) showed low levels of agreement. After the second review, the kappa values of the four major pathological features increased from 0.3830 to 0.5638 for steatosis grade, from 0.1398 to 0.2815 for lobular inflammation, from 0.1923 to 0.3362 for ballooning degeneration, and from 0.3303 to 0.4664 for fibrosis. CONCLUSIONS: More detailed histomorphological criteria must be defined for correct diagnosis and high interobserver agreement of NAFLD.

Prognostic Significance of Defining L-Cell Type on the Biologic Behavior of Rectal Neuroendocrine Tumors in Relation with Pathological Parameters / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: In 2010, the World Health Organization categorized L-cell type neuroendocrine tumors (NETs) as tumors of uncertain malignancy, while all others were classified as malignant. However, the diagnostic necessity of L-cell immunophenotyping is unclear, as are tumor stage and grade that may guide diagnosis and management. To clarify the predictive markers of rectal neuroendocrine neoplasms (NENs), 5- and 10-year overall survival (OS) was analyzed by pathological parameters including L-cell phenotype. MATERIALS AND METHODS: A total of 2,385 rectal NENs were analyzed from our previous multicenter study and a subset of 170 rectal NENs was immunophenotyped. RESULTS: In univariate survival analysis, tumor grade (p 10, is useful in defining L-Cell type. In this study, an L-cell immunophenotype was found in 83.5% of all rectal NENs and most, but not all L-cell type tumors were NET G1, small (< 10 mm) and confined to the mucosa/submucosa. CONCLUSION: From these results, the biological behavior of rectal NENs does not appear to be determined by L-cell type alone but instead by a combination of pathological parameters.

Expression of the Cancer Stem Cell Markers CD44 and CD133 in Colorectal Cancer: An Immunohistochemical Staining Analysis

PURPOSE: The aim of this study was to assess the expressions of CD44 and CD133 in colorectal cancer tissue by using immunohistochemical staining and to analyze the clinical significance of the expressions related to other clinicopathological data and survival results. METHODS: One hundred sixty-two patients with a biopsy-proven colorectal adenocarcinoma who were operated on between January 1998 and August 2004 were enrolled in this study. Immunohistochemical staining for CD44 and CD133 was performed on primary colorectal cancer tissue, metastatic lymph nodes, and synchronous and metachronous metastatic tumor tissues if available. RESULTS: CD44 expression was stronger in the primary tumor than in metastatic lymph nodes (P < 0.001), and CD133 expression tended to be stronger in primary tumor than in metastatic lymph nodes (P = 0.057). No significant correlation was found between the CD44 and the CD133 expressions. The cases with recurrence showed low expression of CD44 (P = 0.017). CD133 expression was lower in cases with elevated CA 19-9 serum levels (P = 0.028) and advanced T stage (P = 0.038). Multivariate analysis proved that low expression of CD44 was an independent prognosis factor for short disease-free survival (P = 0.028). CONCLUSION: Low CD44 expression was correlated with increased tumor recurrence and short disease-free survival, and low CD133 expression was associated with advanced tumor stage. We suggest that further studies be performed to evaluate whether the immunohistochemical method for determining the CD44 and the CD133 expressions is appropriate for exploring cancer stem-cell biology in patients with colorectal cancer.

Diminutive and Small Colorectal Polyps: The Pathologist's Perspective

Recent progress in advanced endoscopic imaging and electronic chromoendoscopy allows the real-time endoscopic estimation of the histologic type of polyps, mainly for the differentiation of adenomas from hyperplastic polyps. Accordingly, a "resect-and-discard" strategy applied to diminutive colorectal polyps is now one of the emerging issues among gastroenterologists. The strategy has a practical advantage in terms of the potential cost savings. However, it has a number of limitations in the medical, academic, and legal aspects. The major pitfalls include the endoscopic investigation of colorectal polyps with a wide variety of histogenetic origins, including serrated polyps, and the lack of a standardized method for polyp size measurement. Another issue is the importance of the pathologic diagnosis for legal purposes and medical research. Moreover, it is not certain whether the implementation of the strategy has economic benefit in countries with an undervalued reimbursement system for pathologic examination. There is no doubt that a highly confident optical diagnosis of polyp type is a novel valuable tool. It can provide a more steady symbiosis between gastroenterologists and pathologists to allow a more evident diagnosis and management of patients with colorectal polyps.

Characteristics of Cutaneous Lymphomas in Korea According to the New WHO-EORTC Classification: Report of a Nationwide Study

BACKGROUND: Previously, cutaneous lymphomas were classified according to either the European Organization for the Research and Treatment of Cancer (EORTC) or the World Health Organization (WHO) classification paradigms. The aim of this study was to determine the relative frequency of Korean cutaneous lymphoma according to the new WHO-EORTC classification system. METHODS: A total of 517 patients were recruited during a recent 5 year-period (2006-2010) from 21 institutes and classified according to the WHO-EORTC criteria. RESULTS: The patients included 298 males and 219 females, and the mean age at diagnosis was 49 years. The lesions preferentially affected the trunk area (40.2%). The most frequent subtypes in order of decreasing prevalence were mycosis fungoides (22.2%), peripheral T-cell lymphoma (17.2%), CD30+ T-cell lymphoproliferative disorder (13.7%), and extranodal natural killer/T (NK/T) cell lymphoma, nasal type (12.0%). Diffuse large B-cell lymphoma accounted for 11.2% of cases, half of which were secondary cutaneous involvement; other types of B-cell lymphoma accounted for less than 1% of cases. CONCLUSIONS: In comparison with data from Western countries, this study revealed relatively lower rates of mycosis fungoides and B-cell lymphoma in Korean patients, as well as higher rates of subcutaneous panniculitis-like T-cell lymphoma and NK/T cell lymphoma.

Prognostic Significance of Ki-67 Expression in Patients Undergoing Surgical Resection for Gastrointestinal Stromal Tumor / 대한소화기학회지

BACKGROUND/AIMS: Assessment of malignant potential in gastrointestinal stromal tumor (GIST) is still problematic. The maximum tumor diameter and the mitotic index are generally used as an index of malignancy of GISTs. The Ki-67 labeling index has recently been used as an index of cell growth. The aim of this study was to investigate the prognostic value of Ki-67 in GIST. METHODS: We retrospectively reviewed the medical records of 32 patients with GIST who underwent surgical resection at Inje University Seoul Paik Hospital. We analyzed their Ki-67 expression, histologic finding, and prognosis. RESULTS: According to the tumor size and mitotic count, 4 patients were classified as very low risk, 9 patients as low risk, 14 patients as intermediate risk and 5 patients as high risk. The average Ki-67 index was 5.56+/-4.48%. The median follow-up duration was 35.72+/-29.04 months, and local/distant recurrences were observed in 6 (18.7%) patients. The overall cumulative disease free survival rates in patients with Ki-67 index 5% were at 1 year, 2 years, and 5 years were 82.1%, 70.3%, and 46.9%, respectively. There was significant relationship between elevated Ki-67 and disease free survival rate (p=0.007). CONCLUSIONS: Our study suggests that Ki-67 index >5% confers a higher risk of relapse in patients with GIST. Future work should focus on standardization of Ki-67 assessment and specification of its role in making treatment decisions.

Miniprobe Endoscopic Ultrasonography Has Limitations in Determining the T Stage in Early Colorectal Cancer

BACKGROUND/AIMS: Mini-probe endoscopic ultrasonography (mEUS) is a useful diagnostic tool for accurate assessment of tumor invasion. The aim of this study was to estimate the accuracy of mEUS in patients with early colorectal cancer (ECC). METHODS: Ninety lesions of ECC underwent mEUS for pre-treatment staging. We divided the lesions into either the mucosal group or the submucosal group according to the mEUS findings. The histological results of the specimens were compared with the mEUS findings. RESULTS: The overall accuracy for assessing the depth of tumor invasion (T stage) was 84.4% (76/90). The accuracy of mEUS was significantly lower for submucosal lesions compared to mucosal lesions (p=0.003) and it was lower for large tumors (> or =2 cm) (p=0.034). The odds ratios of large tumors and submucosal tumors affecting the accuracy of T staging were 3.46 (95% confidence interval [CI], 1.05 to 11.39) and 6.25 (95% CI, 1.85 to 25.14), respectively. When submucosal tumors were combined with large size, the odds ratio was 14.67 (95% CI, 1.46 to 146.96). CONCLUSIONS: The overall accuracy of T stage determination with mEUS was considerably high in patients with ECC; however, the accuracy decreased when tumor size was >2 cm or the tumor had invaded the submucosal layer.

Proposal for a Standardized Pathology Report of Gastroenteropancreatic Neuroendocrine Tumors: Prognostic Significance of Pathological Parameters

BACKGROUND: There is confusion in the diagnosis and biological behaviors of gastroenteropancreatic neuroendocrine tumors (GEP-NETs), because of independently proposed nomenclatures and classifications. A standardized form of pathology report is required for the proper management of patients. METHODS: We discussed the proper pathological evaluation of GEP-NET at the consensus conference of the subcommittee meeting for the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. We then verified the prognostic significance of pathological parameters from our previous nationwide collection of pathological data from 28 hospitals in Korea to determine the essential data set for a pathology report. RESULTS: Histological classification, grading (mitosis and/or Ki-67 labeling index), T staging (extent, size), lymph node metastasis, and lymphovascular and perineural invasion were significant prognostic factors and essential for the pathology report of GEP-NET, while immunostaining such as synaptophysin and chromogranin may be optional. Furthermore, the staging system, either that of the 2010 American Joint Cancer Committee (AJCC) or the European Neuroendocrine Tumor Society (ENETS), should be specified, especially for pancreatic neuroendocrine neoplasms. CONCLUSIONS: A standardized pathology report is crucial for the proper management and prediction of prognosis of patients with GEP-NET.

Early Colorectal Epithelial Neoplasm in Korea: A Multicenter Survey of Pathologic Diagnosis

BACKGROUND: The incidence of early colorectal epithelial neoplasm (ECEN) is increasing, and its pathologic diagnosis is important for patient care. We investigated the incidence of ECEN and the current status of its pathologic diagnosis. METHODS: We collected datasheets from 25 institutes in Korea for the incidence of colorectal adenoma with high grade dysplasia (HGD) and low grade dysplasia in years 2005, 2007, and 2009; and early colorectal carcinoma in the year 2009. We also surveyed the diagnostic terminology of ECEN currently used by the participating pathologists. RESULTS: The average percentage of diagnoses of adenoma HGD was 7.0%, 5.0%, and 3.4% in years 2005, 2007, and 2009, respectively. The range of incidence rates of adenoma HGD across the participating institutes has gradually narrowed over the years 2005 to 2009. The incidence rate of early colorectal carcinoma in the year 2009 was 21.2%. The participants did not share a single criterion or terminology for the diagnosis of adenoma HGD. The majority accepted the diagnostic terms that distinguished noninvasive, mucosal confined, and submucosal invasive carcinoma. CONCLUSIONS: Further research requirements suggested are a diagnostic consensus for the histopathologic diagnosis of ECEN; and standardization of diagnostic terminology critical for determining the disease code.

Prognostic Significance of Ki-67 Expression in Rectal Carcinoid Tumors / 대한소화기학회지

BACKGROUND/AIMS: Rectal carcinoid tumors can be resected with endoscopy, and it is important to assess their prognostic factors. We evaluated the potential of Ki-67 expression as a prognostic factor in rectal carcinoid tumors. METHODS: We retrospectively reviewed the medical records of 37 patients with rectal carcinoid tumors who got endoscopic resection from January 2001 to January 2011 at Inje University Seoul Paik Hospital. We analyzed their endoscopic and histologic findings, Ki-67 expression, clinical outcome, and prognosis. RESULTS: The mean age (+/-SD) of the patients was 56.3+/-10.7 years, and the male : female ratio was 3.6:1. The mean tumor size was 0.5+/-0.4 cm, 33 patients showed grade 1 tumors (89.2%) and the average Ki-67 expression was 0.7+/-1.2%. Thirty five patients underwent endoscopic mucosal resection, and two required endoscopic submucosal dissection. Eight patients had positive margins after resection, but no cases of lymphovascular invasion were identified. The median follow-up duration was 21.4+/-25.4 months, and no recurrences were observed. CONCLUSIONS: In low grade rectal carcinoid tumors which are lack of central depression on colonoscopy, the expression of a molecular marker of malignant potential, Ki-67, was low. Therefore, endoscopic resection seemed to be a safe and effective treatment for these tumors.

Update on the Proposal for Creating a Guideline for Cancer Registration of the Gastrointestinal Tumors (I-2)

BACKGROUND: Cancer registries play a fundamental role in cancer control and multicenter collaborative research. Recently, the need for reassessment of cancer registry criteria has arisen due to the newly released 2010 World Health Organization (WHO) classification. Accordingly, development of new coding guidelines for cancer is necessary to improve the quality of cancer registries, as well as to prevent conflicts that may arise when seeking medical insurance compensation. METHODS: With funding from the Management Center for Health Promotion, 35 members of the Gastrointestinal Pathology Study Group and the Cancer Registration Committee of the Korean Society of Pathologists (KSP) participated in a second workshop for gastrointestinal tumor registration in Korea. RESULTS: The topics of gastric epithelial tumor, colonic intramucosal carcinoma, neuroendocrine tumor (NET), gastrointestinal stromal tumor (GIST) and appendiceal mucinous tumor were discussed for new coding guidelines. A survey was then conducted among 208 members of the KSP for a consensus of the guidelines proposed in the workshop. CONCLUSIONS: Although a few issues were set aside for further discussion, such as coding for non-gastric GIST and some types of NET, the members agreed upon most of the proposed guidelines. Therefore, we suggest using the newly revised International Classification of Diseases for Oncology, 3rd edition (ICD-O-3) coding guidelines for registering gastrointestinal tumors in Korea.