Prognostic Significance of Intratumoral and Peritumoral Budding in Distal Extrahepatic Bile Duct Carcinoma.

INTRODUCTION: Although tumor budding (TB) has been recognized as a representative adverse prognosticator in gastrointestinal malignancies, it is not well elucidated in distal extrahepatic bile duct carcinoma (DBDC). Herein, we investigated the prognostic significance of peritumoral (PTB) and intratumoral (ITB) budding according to the modified DBDC staging of the 8th edition of the American Joint Committee on Cancer. METHODS: PTB and ITB were independently evaluated in a cohort of DBDC patients (n = 410) based on the 2016 International Tumor Budding Consensus Conference. RESULTS: High levels of PTB (PTBHigh, ≥ grade-2) and ITB (ITBHigh, ≥ grade-3) were identified in 316 (77%) and 238 (58%) cases, respectively. In univariate analysis, PTBHigh and ITBHigh, larger size and sclerosing tumor growth pattern, higher histologic grade, extrapancreatic location, adenocarcinomas unrelated to intraductal papillary neoplasm of the bile duct, pancreatic, duodenal, and lymphovascular invasion, perineural invasion, cancer involvement of the bile duct resection margin, nodal metastasis, and higher T and N categories and disease stages were associated with shorter patient overall survival (OS) times. In multivariate analysis, PTBHigh and ITBHigh remained poor independent prognostic indicators of OS in DBDC patients. Specifically, ITBHigh could predict poor prognosis in patients with stage I (T1N0) DBDC. CONCLUSIONS: Both PTBHigh and ITBHigh were strong prognostic indicators in patients with DBDC. Thus, ITB could be used to predict worse prognoses in patients with DBDC, in which PTB is difficult to assess, especially for patients with stage I (T1N0) DBDC.

Prognostic significance of tertiary lymphoid structures in gastric neuroendocrine carcinoma with association to delta-like ligand 3 and neuroendocrine expressions.

BACKGROUND: Gastric neuroendocrine carcinomas (NECs) are rare cancers with highly aggressive behavior. Although tertiary lymphoid structures (TLSs) are well-known prognostic factors in various cancers, their role in gastric NECs remain unexplored. Unique immunohistochemical subtypes of pulmonary NECs have been discovered, however, their feasibility in gastric NECs is unknown. METHODS: The presence and maturation of TLSs (lymphoid aggregates, primary and secondary follicles) were assessed in 48 surgically resected gastric NECs and were compared with immunohistochemical subtypes, using a panel of ASCL1, NeuroD1, POU2F3, YAP1, and DLL3 with three neuroendocrine (NE) markers. RESULTS: Patients with secondary follicles had significantly better overall survival (OS) and recurrence-free survival (RFS; both, p = 0.004) than those without them. Based on the hierarchical clustering, gastric NECs were classified into all low/negative (31%), high-YAP1 (19%), high-DLL3/low-NE (29%), and high-NE (21%) expression groups. The high-DLL3/low-NE group was associated with absent TLSs (p = 0.026) and showed the worst OS (p = 0.026). Distant metastasis and a lack of secondary follicles were poor independent prognostic factors of OS and RFS. CONCLUSION: The assessment of TLSs is a feasible and potent biomarker for gastric NECs, thus enabling better prognosis and more effective immunotherapy. Furthermore, gastric NECs can be categorized as four immunohistochemically distinct groups, of which the high-DLL3/low-NE group has the worst OS with lack of TLSs.

Granulocytic epithelial lesion (GEL) in heterotopic pancreas.

BACKGROUND: The diagnosis of type 2 autoimmune pancreatitis (AIP) is dependent on typical radiologic imaging and the presence of the granulocytic epithelial lesion (GEL), which is characterized by ductal neutrophilic infiltration with or without neutrophilic acinar infiltration. METHODS: We evaluated GEL and related clinicopathologic factors in 165 resected heterotopic pancreata (HPs) [57 gastric (35%), 56 duodenal (34%), 30 omental (18%), and 22 jejunal (13%)] and 29 matched orthotopic pancreata routinely examined during surgery. RESULTS: GEL was noted in 8% (13/165) of HPs, including ductal epithelial (6/13, 46%) and intraluminal (8/13, 62%) neutrophilic infiltrations. However, there was no GEL in orthotopic pancreata. Abdominal pain was observed in 6 (46%) patients with GEL-positive HPs. GEL was more commonly observed in HPs having symptoms (p = 0.029), a larger size (p = 0.028), and an infiltrative growth pattern (p = 0.006). In addition, periductal lymphoplasmacytic infiltration and fibrosis (both p < 0.001), interstitial fibrosis (p = 0.017), acinar neutrophilic infiltration (p = 0.032), venulitis (p = 0.050), acinar ductal metaplasia (ADM; p = 0.040), and pancreatic intraepithelial neoplasia/intraductal papillary mucinous neoplasms (PanIN/IPMN; p < 0.001) were more commonly seen in HPs with GEL than in those without GEL. Inflammatory bowel disease was present only in one patient with GEL-negative HP. CONCLUSIONS: GELs are detected in a subset of HPs without clinical evidence of AIP. Therefore, for the diagnosis of AIP, GEL should be carefully interpreted with the context of other histologic, clinical, and radiologic findings.

Clinicopathologic and Molecular Characteristics of and Diagnostic Dilemmas in Invasive Breast Carcinoma with Choriocarcinomatous Pattern apropos a New Case: A Literature Review with New Findings.

BACKGROUND: Invasive breast carcinoma with a choriocarcinomatous pattern (IBC-CP) is extremely rare, and its molecular basis is yet unclear. The choriocarcinomatous pattern is characterized by the biphasic arrangement of multinucleated syncytiotrophoblast-like cells around clusters of monotypic tumor cells in a hemorrhagic background, along with ß-human chorionic gonadotropin (ß-hCG) expression. The differentiation of IBC-CP from metastatic choriocarcinoma of the breast (MC-B) is difficult due to the histologic similarity. METHODS: Based on a literature review and our own case, the clinicopathologic differences between IBC-CP patients (n = 17) and MC-B patients (n = 8) were analyzed. Moreover, in our case of IBC-CP, next-generation sequencing (NGS) comparative analysis was conducted for both choriocarcinomatous and invasive breast carcinoma (IBC) components. RESULTS: Compared to the MC-B patients, the IBC-CP patients were older (p < 0.001) and less frequently had past histories of gestational trophoblastic disease/pregnancy/abortion (p = 0.001) and distant metastases (p = 0.005). Our case, a 49-year-old female patient, presented with masses in the right breast and axilla. Following neoadjuvant chemotherapy, a radical mastectomy found an 8.5-cm-sized tumor. Microscopically, multinucleated syncytiotrophoblast-like cells were observed around mononuclear tumor cells with hemorrhage and necrosis. Some tumor cells showed ß-hCG immunopositivity, which was compatible with IBC-CP. NGS results showed a missense mutation in exon 5 of the TP53 gene in both the choriocarcinomatous and IBC components. Meanwhile, copy number loss in the PTEN gene was only identified in the choriocarcinomatous components. CONCLUSION: The present IBC-CP case is triple-negative breast cancer with TP53 mutation. The PTEN gene may be associated with choriocarcinomatous differentiation. Obtaining a medical history is mandatory to exclude metastatic lesions.

Pancreatic Cysts after Endoscopic Ultrasonography-Guided Ethanol and/or Paclitaxel Ablation Therapy: Another Mimic of Pancreatic Pseudocysts.

BACKGROUND: Endoscopic ultrasound-guided ablation (EUS-A) therapy is a minimally invasive procedure for pancreatic-cystic tumors in patients with preoperative comorbidities or in patients who are not indicated for surgical resection. However, histopathologic characteristics of pancreatic cysts after ablation have not been well-elucidated. METHODS: Here, we analyzed pathological findings of 12 surgically resected pancreatic cysts after EUS-A with ethanol and/or paclitaxel injection. RESULTS: Mean patient age was 49.8 ± 13.6 years with a 0.3 male/female ratio. Clinical impression before EUS-A was predominantly mucinous cystic neoplasms. Mean cyst size before and after ablation therapy was similar (3.7 ± 1.0 cm vs. 3.4 ± 1.6 cm; p = 0.139). Median duration from EUS-A to surgical resection was 18 (range, 1-59) months. Mean percentage of the residual neoplastic lining epithelial cells were 23.1 ± 37.0%. Of the resected cysts, 8 cases (67%) showed no/minimal (<5%) residual lining epithelia, while the remaining 4 cases (33%) showed a wide range of residual mucinous epithelia (20-90%). Ovarian-type stroma was noted in 5 cases (42%). Other histologic features included histiocytic aggregation (67%), stromal hyalinization (67%), diffuse egg shell-like calcification along the cystic wall (58%), and fat necrosis (8%). CONCLUSION: Above all, diffuse egg shell-like calcification along the pancreatic cystic walls with residual lining epithelia and/or ovarian-type stroma were characteristics of pancreatic cysts after EUS-A. Therefore, understanding these histologic features will be helpful for precise pathological diagnosis of pancreatic cystic tumor after EUS-A, even without knowing the patient's history of EUS-A.

Hot snare polypectomy versus endoscopic mucosal resection for small colorectal polyps: a randomized controlled trial.

BACKGROUND AND AIMS: This study was performed to compare endoscopic mucosal resection (EMR) with hot snare polypectomy (HSP) in terms of the complete resection rate and the incidence of adverse events for resecting small (5-10 mm) colorectal polyps. METHODS: Small colorectal polyps (5-10 mm) with neoplastic features were randomly allocated to either the HSP or EMR group. A submucosal injection was performed prior to hot snaring in the EMR group only. Complete resection was defined as the absence of neoplastic tissue from two additional biopsies of the polypectomy site. R0 resection was defined as the absence of neoplastic tissue at the margin of the resected specimen. RESULTS: A total of 362 colon polyps from 272 patients were included, and 167 polyps in the HSP group and 155 polyps in the EMR group were analyzed. Between the polypectomy techniques, there was no significant difference in the complete resection rates, which were 96.4% (161/167) in the HSP group and 95.5% (148/155) in the EMR group (P = 0.67). The R0 resection rate in the HSP and EMR groups was significantly different, with 49.7% (83/167) and 74.8% (116/155), respectively (P < 0.001). There was no significant difference in the incidence of adverse events between the two groups. CONCLUSIONS: The complete resection rates for small (5-10 mm) polyps were not different between HSP and EMR. TRIAL REGISTRY: ClincialTrials.gov number NCT02239536.

Jumbo biopsy forceps versus cold snares for removing diminutive colorectal polyps: a prospective randomized controlled trial.

BACKGROUND AND AIMS: Cold snare polypectomy (CSP) and jumbo forceps polypectomy (JFP) have been shown to be effective for removing diminutive colorectal polyps (DCPs) (≤5 mm). However, no study has compared complete resection rates between CSP and JFP for DCPs. The aim of this study was to compare the efficacy and safety of JFP with CSP for the removal of DCPs. METHODS: This was a prospective randomized controlled trial from 2 tertiary-care referral centers. A total of 1003 patients were screened, and 169 patients with 196 DCPs were enrolled. The main outcome was complete polyp resection rate. RESULTS: Of 196 diminutive polyps, 177 (90.3%) were adenomatous polyps. The overall complete resection rate was 92.1% (163/177). The complete resection rate was not significantly different between JFP and CSP groups (92.0% vs 92.2%; P = .947). JFP achieved complete resection rates comparable with CSP for polyps >3 mm (90.3% vs 89.8%; P = .928). Polypectomy procedure time, tissue retrieval rate, and rate of postpolypectomy adverse events were not significantly different between the 2 groups. CONCLUSIONS: Both JFP and CSP achieved complete resection rates of >90% for DCPs. Thus, JFP may be considered for polypectomy of DCPs. (International clinical trial registry number: KCT0002805.).

Clinicopathological and prognostic significance of heme oxygenase-1 expression in small intestinal adenocarcinomas.

Heme oxygenase-1 (HO-1), a stress-response protein, is highly induced in various carcinomas. It is implicated in carcinogenesis and tumor progression. High HO-1 expression is associated with better prognosis of patients with colorectal and gastric cancers. Induction or inhibition of HO-1 can mediate chemo-sensitivity, therefore it might be a therapeutic target to develop anticancer agents. To define the clinicopathological and prognostic significance of HO-1 expression in small-intestinal adenocarcinomas (SIACs), immunohistochemical microarray analysis of HO-1 expression was performed for 191 surgically resected SIAC cases and results were compared with various clinicopathologic variables, including survival. HO-1 was highly expressed in 127 (66.5%) cases. Patients with high HO-1 expression were associated with younger age (P = 0.048), lower pT category (P = 0.017), and less pancreatic invasion (P = 0.047). Patients with high HO-1 expression tended to have longer overall survival (median, 38.5 months) than those with low HO-1 expression (24.5 months), although the difference in overall survival was not statistically significant (P = 0.677). In summary, high HO-1 expression is frequently observed in SIACs. It is related to favorable clinicopathologic parameters, including younger age, lower T category, and less pancreatic invasion. Therefore, HO-1 may serve as a prognostic marker and a new target to modulate chemotherapeutic effects in patients with SIACs.

Clinicopathologic and prognostic associations of KRAS and BRAF mutations in small intestinal adenocarcinoma.

Activating KRAS and/or BRAF mutations have been identified as predictors of resistance to anti-epidermal growth factor receptor (EGFR) chemotherapy in colorectal cancer. But the status of KRAS and BRAF mutations and their clinicopathologic and prognostic significance has not been extensively evaluated in small intestinal adenocarcinomas. In this work, the KRAS and BRAF genes in 190 surgically resected small intestinal adenocarcinoma cases were sequenced and their association with various clinicopathologic variables, including survival of the patients, was analyzed. KRAS or BRAF mutations were observed in 63 (33%) cases. Sixty-one cases had KRAS mutations and 2 had BRAF mutations and the two types of mutation were mutually exclusive. The majority of KRAS mutations were G>A transition (43/61 cases, 71%) or p.G12D (31/61 cases, 51%). The patients with mutant KRAS tended to have higher pT classifications (P=0.034) and more frequent pancreatic invasion (P=0.020) than those with wild-type KRAS. Multivariate logistic regression analysis showed that certain mutated KRAS subtypes (G>A transitions and G12D mutations) were significantly correlated with higher pT classification (P=0.015 and 0.004, respectively) than wild-type KRAS and other KRAS mutations. The patients with KRAS or BRAF mutation had a tendency to shorter overall survival than those with wild-type KRAS and BRAF (P=0.148), but subgroup analysis demonstrated the patients with KRAS mutations showed worse survival (median, 46.0 months; P=0.046) than those with wild-type KRAS (85.4 months) in lower pT classification (pT1-pT3) group. In summary, KRAS and, infrequently, BRAF mutations are observed in a subset of small intestinal adenocarcinomas, and are associated with higher pT classification and more frequent pancreatic invasion. KRAS mutation is a poor prognostic predictor in patients with lower pT classification tumors. Anti-EGFR targeted therapy could be applied to about two-thirds of small intestinal adenocarcinoma patients, namely those with wild-type KRAS and BRAF if they have metastatic disease, similar to colorectal cancer patients.

Diagnostic yield of endoscopic ultrasonography-guided single-incision needle knife biopsy for gastric subepithelial tumors: comparison with resected specimens.

BACKGROUND: Several techniques are recommended for the histologic diagnosis of gastric subepithelial tumors (SETs). The purpose of our study was to evaluate the diagnostic yield and safety of endoscopic ultrasonography-guided single-incision needle knife (SINK) biopsy for the diagnosis of gastric SETs. METHODS: A retrospective review of patients who received biopsy for gastric SETs from August 2012 to May 2015 was conducted. Patients who received endoscopic ultrasonography and were found to have a SET originating from the muscularis propria of the stomach were included in the study. The aim of our study was to investigate the safety and diagnostic yield of SINK biopsy for gastric SETs. RESULTS: A total of 31 patients received SINK biopsy for SETs. The diagnostic yield of SINK biopsy was 87 % (95 % CI 75-100 %), and the diagnostic accuracy was 89 % (95 % CI 74-105 %). The sensitivity of SINK biopsy to identify gastrointestinal stromal tumors was 83 % (95 % CI 52-98 %); the specificity was 100 % (95 % CI 59-100 %); the positive predictive value was 100 % (95 % CI 69-100 %); and the negative predictive value was 78 % (95 % CI 40-97 %). There were no procedure-related adverse events during and after procedure. CONCLUSION: The use of SINK biopsy technique in patients with SETs is a good diagnostic tool with high diagnostic yield and accuracy. The method is simple, safe, and associated with few complications.

Cold snare polypectomy versus cold forceps polypectomy for diminutive and small colorectal polyps: a randomized controlled trial.

BACKGROUND: The optimal technique for removal of diminutive or small colorectal polyps is debatable. OBJECTIVE: To compare the complete resection rates of cold snare polypectomy (CSP) and cold forceps polypectomy (CFP) for the removal of adenomatous polyps ≤7 mm. DESIGN: Prospective randomized controlled study. SETTING: A university hospital. PATIENTS: A total of 139 patients who were found to have ≥1 colorectal adenomatous polyps ≤7 mm. INTERVENTIONS: Polyps were randomized to be treated with either CSP or CFP. After the initial polypectomy, additional EMR was performed at the polypectomy site to assess the presence of residual polyp tissue. MAIN OUTCOME MEASUREMENTS: Absence of residual polyp tissue in the EMR specimen of the polypectomy site was defined as complete resection. RESULTS: Among a total of 145 polyps, 128 (88.3%) were adenomatous polyps. The overall complete resection rate for adenomatous polyps was significantly higher in the CSP group compared with the CFP group (57/59, 96.6% vs 57/69, 82.6%; P = .011). Although the complete resection rates for adenomatous polyps ≤4 mm were not different (27/27, 100% vs 31/32, 96.9%; P = 1.000), the complete resection rates for adenomatous polyps sized 5 to 7 mm was significantly higher in the CSP group compared with the CFP group (30/32, 93.8% vs 26/37, 70.3%; P = .013). LIMITATIONS: Single-center study. CONCLUSION: CSP is recommended for the complete resection of colorectal adenomatous polyps ≤7 mm. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01665898.).

Prognostic significance of CDX2 and mucin expression in small intestinal adenocarcinoma.

The clinicopathological and prognostic significance of CDX2 and mucin expression have not been comprehensively evaluated in small intestinal adenocarcinoma. Immunohistochemical microarray analyses of CDX2, MUC1, MUC5AC, and MUC6 protein expressions in 189 surgically resected small intestinal adenocarcinoma cases were examined and compared with various clinicopathologic variables, including survival. CDX2, MUC1, MUC5AC, and MUC6 expressions were observed in 43.4% (82 patients), 37.6% (71), 31.7% (60), and 21.7% (41) of patients, respectively. Whereas CDX2 expression was found to be associated with low-grade tumors (P=0.034), fewer nodal metastases (P=0.019), and less perineural invasion (P=0.049) in small intestinal adenocarcinoma patients, patients expressing MUC1 tended to demonstrate high-grade (P=0.021) and nodular or infiltrative (P=0.020) tumors. On the basis of the combined CDX2, MUC1, MUC5AC, and MUC6 expression patterns, small intestinal adenocarcinoma patients were further classified as intestinal (CDX2+/MUC1-; 29.6%), pancreatobiliary (CDX2-/MUC1+; 23.8%), mixed (CDX2+/MUC1+; 13.8%), gastric (CDX2-/MUC1-/MUC5AC+ or MUC6+; 13.8%), or null (CDX2-/MUC1-/MUC5AC-/MUC6-; 19.0%). Among these immunophenotypes, intestinal-type patients demonstrated more frequent distal (jejunal or ileal; P=0.033), tubular (P=0.039), and low-grade tumors (P=0.004) and significantly better survival according to univariate (P<0.0001) and multivariate (P=0.001) analyses. In summary, intestinal immunophenotype adenocarcinomas are associated with distal (jejunal or ileal), tubular, and low-grade tumors and better survival outcomes. Hence, CDX2 and mucin immunohistochemical staining may provide better estimations of survival after surgical resection and intestinal immunophenotype could therefore be used as a better prognostic indicator of small intestinal adenocarcinoma.

Prognostic significance of single isolated cells with decreased E-cadherin expression in pseudomyxoma peritonei.

Pseudomyxoma peritonei (PMP) cases can be classified into the prognosis-related subtypes of disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA). To investigate the mechanisms of mucinous invasion and the differing prognoses of these two subtypes, we examined the expression levels of proteins involved in cellular adhesion and invasion, including E-cadherin, vimentin, ß-catenin, and S100A4, in single isolated tumor cells (SICs) and cohesive cellular strips within mucin pools isolated from DPAM (n = 31) and PMCA (n = 21) patients. In both PMCA and DPAM cases, SICs showed a complete loss of E-cadherin expression, whereas cells in cohesive cellular clusters retained E-cadherin expression. The frequency of high numbers of SICs (>8) in PMCA cases was significantly greater than that in DPAM cases (86% and 26%, respectively) and was correlated with poor progression-free survival (P = 0.019) in a univariate analysis. In both PMP subtypes, strong vimentin expression was identified in most of the SICs but not the cohesive cellular strips. The relatively slow progression of DPAM may be attributable to the smaller number of SICs that lack E-cadherin expression and have increased vimentin expression, whereas the rapid progression of PMCA may be due to larger numbers of these SICs.

Stage Evaluation of Cystic Duct Cancer.

Purpose: Cystic duct cancers (CDCs) have been classified as extrahepatic bile duct cancers or gallbladder cancers (GBCs); however, it is unclear whether their clinical behavior is similar to that of distal extrahepatic bile duct cancers (DBDCs) or GBCs. Materials and Methods: T category of the CDCs was classified using current T category scheme of the GBCs and DBDCs, and clinicopathological factors were compared among 38 CDCs, 345 GBCs, and 349 DBDCs. We modified Nakata's classifications (type 1, confined within cystic duct (CD); combined types 2-4, extension beyond CD) and compared them. Results: No significant overall survival (OS) difference was observed between the patients with CDC, GBC, and DBDC. The T category of GBC staging was more accurate at distinguishing OS in patients with CDC than the DBDC staging. Patients with T3 CDC and GBC showed a significant OS difference when using the T category for GBC staging, while those with T1-T2 CDC and GBC showed no significant difference. In contrast, the T category of DBDC staging did not show any significant OS difference between patients with T1-T2 CDC and DBDC or T3 CDC and DBDC. Patients with type 1 CDC had significantly better OS than those with combined types. Conclusion: Unlike GBCs and DBDCs, CDCs exhibit distinct clinicopathological characteristics. The OS is better when the CDC confines within the CD, compared to when it extends beyond it. Therefore, we propose a new T category scheme (T1, confined to CD; T2, invaded beyond CD) for better classifying CDCs.

A Nationwide Study on HER2-Low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols.

PURPOSE: Notable effectiveness of trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2 (HER2)-low advanced breast cancer (BC) has focused pathologists' attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results. MATERIALS AND METHODS: The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected. RESULTS: Total 11,416 patients from 25 institutions included in this study. Of these patients, 40.7% (range, 6.0% to 76.3%) were classified as HER2-zero, 41.7% (range, 10.5% to 69.1%) as HER2-low, and 17.5% (range, 6.7% to 34.0%) as HER2-positive. HER2-low tumors were associated with positive estrogen receptor and progesterone receptor statuses (p < 0.001 and p < 0.001, respectively). Antigen retrieval times (≥ 36 minutes vs. < 36 minutes) and antibody incubation times (≥ 12 minutes vs. < 12 minutes) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3,259) of the patients. CONCLUSION: The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Practice guidelines for managing extrahepatic biliary tract cancers.

Backgrounds/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions: The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Clear cell carcinomas of the ovary: a multi-institutional study of 129 cases in Korea with prognostic significance of Emi1 and Galectin-3.

Accurate diagnosis of ovarian clear cell carcinoma (CCC) is important because of its poor prognosis with chemoresistance and a high recurrent rate. The clinicopathologic characteristics and prognostic significance of the cell cycle regulator [early mitotic inhibitor-1 (Emi1)] and galactoside-binding protein (Galectin-3) were evaluated. Among 155 CCCs from 18 hospitals in Korea between 1995 and 2006, 129 pure CCCs were selected with consensus using immunohistochemical stains for hepatocyte nuclear factor-1ß, Wilms' tumor protein, and estrogen receptor. The expressions of Emi1, Galectin-3, p53, and Ki-67 labeling index were analyzed with clinicopathologic parameters and the patient's survival. The mean age of the patients was 49.6 yr; the tumors were bilateral in 10.9%, and the average size was 12 cm. Adenofibromatous component was found in 7%, and endometriosis in 48.1% of the cases. Psammoma body was seen in 16.3%. Disease-free survival and overall survival rates were 78.3% and 79.1%, respectively. The International Federation of Obstetrics and Gynecology (FIGO) stage was the most important prognostic indicator. Emi1 expression (>5%) was seen in 23.3% of CCCs, and associated with high FIGO grades and poor overall survival (P<0.05). High Galectin-3 (≥80%) expression was seen in 59.7% of CCCs, and associated with FIGO stages III and IV, and high Ki-67 labeling index. High Ki-67 labeling index (≥50%) and p53 expression (≥50%) were seen in 27.1% and 18.6% of CCCs, respectively, but there was no clinicopathologic and prognostic significance. On the basis of the fact that the expression of Emi1 in CCC was correlated with a high histologic grade and worse overall survival, target therapy using inhibitors of Emi1 may be tried in the management of CCC patients with Emi1 expression.

Loss of S100A14 expression is associated with the progression of adenocarcinomas of the small intestine.

OBJECTIVES: Small intestinal adenocarcinoma (SIAC) is an exceedingly rare human malignant tumor, and its association with the S100A14 gene is not known yet. We aimed to investigate the clinicopathological correlations between S100A14 expression and SIAC. METHODS: Immunohistochemical analyses of S100A14, p21 and p53 were performed using tissue microarray analysis of 175 surgically resected SIACs. RESULTS: Of 175 SIACs, loss of S100A14 expression was observed in 128 cases (73.1%). Loss of S100A14 expression was associated with lymph node metastasis (p = 0.009) and advanced disease stage (p = 0.013), and was more frequently observed in distal than duodenal tumors (p = 0.043). The majority of SIACs lost p21 expression (93.7%), and significant loss of p21 expression was observed in cancers with high pT stages (pT(3) and pT(4); p = 0.011), lymph node metastasis (p = 0.029) and advanced cancer stage defined by the American Joint Committee on Cancer (p = 0.005). Overexpression of p53 was found in 23.4% of cases. Positive expression of p53 was associated with distally located SIACs (jejunum or ileum; p = 0.006). There was no association between the expression of S100A14 and p21 or p53. CONCLUSION: Loss of S100A14 in SIAC is common and is associated with higher metastatic potential and advanced clinical stage.

Acquired cystic disease-associated renal cell carcinoma: further characterization of the morphologic and immunopathologic features.

Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a subtype of renal cell carcinoma (RCC) with unique morphologic features found exclusively in the background of end-stage renal disease. We analyzed the clinicopathologic features and immumoreactive profiles of 12 cases of ACD-RCC to further characterize this recently recognized entity. Review of histologic slides was performed in conjunction with immunohistochemical staining directed to the contemporary diagnostic antibodies and the putative target therapy-related markers. Histologically, the tumors showed characteristic inter-or intracellular microlumens and eosinophilic tumor cells. Intratumoral hemosiderin deposition and degenerating foamy tumor cells were consistent findings which were not previously described. Immunohistochemically, all the tumors were positive for alpha-methylacyl-CoA-racemase, CD10, pan-cytokeratin, PTEN (phosphatase and tensin homolog deleted on chromosome 10) and c-met, while negative for carbonic anhydrase-9, CD57, CD68, c-kit, pax-2, platelet-derived growth factor receptor (PDGFR)-α or vascular endothelial growth factor receptor (VEGFR)-2. Heterogenous staining was found for CK7 and kidney-specific cadherin. Positive reaction to c-met suggests its utility as a plausible therapeutic target in ACD-RCC. Thus, we present the unique morphologic and immunopathologic features of ACD-RCC, which may be helpful in both diagnostic and therapeutic aspects.

Prognostic Significance of Cyclin D1 Expression in Small Intestinal Adenocarcinoma.

Cyclin D1, a critical cyclin-dependent kinase (CDK) 4/6-dependent regulator of G1/S transition, has attracted much interest as a therapeutic target. The cyclin D1 expression in small intestinal adenocarcinomas (SIACs) has not yet been comprehensively studied, owing to the rarity of this tumor. We investigated the clinicopathological and prognostic significance of the cyclin D1 expression in 232 surgically resected primary SIACs through a multi-institutional study. A high expression of cyclin D1 (cyclin D1High) was detected in 145 SIAC cases (63%), which was significantly higher than that in normal small intestinal mucosa (11%). Cyclin D1High was more commonly found in SIACs with a lower T-category and disease stage and KRAS mutation and predicted better patient survival. Multivariate analysis revealed that cyclin D1High, the absence of retroperitoneal seeding and lymphovascular invasion, and the lower N-category were identified as independent prognostic indicators for patients with SIACs. Specifically, cyclin D1High affected patient survival in the lower stage group (stages I and II). In conclusion, cyclin D1 was commonly overexpressed in SIACs, and cyclin D1High acted as a favorable prognostic indicator in patients with SIACs. These findings in SIACs may, thus, be important to further comprehend the mechanism of cyclin D1 in carcinogenesis and to strategize appropriate patient therapies.