Appendiceal Neuroendocrine Tumor: Clinicopathologic Characteristics of Six Cases and Review of the Literature.

Background/aim: Appendiceal neuroendocrine tumors (ANETs) are the most prevalent type of appendiceal neoplasm and the fifth most common neuroendocrine tumor in the gastrointestinal tract. In this study, we described the clinicopathological features of patients with ANET.

Patients And Methods: We reviewed the clinicopathological findings and histopathological reports of six patients diagnosed with ANET between January 2014 and December 2023 at Korea University Medical Center, Anam Hospital.

Routine Elastic Staining Helps Detection of Vascular Invasion in Colorectal Cancer: A Comprehensive Analysis of T3 or Higher Tumors Without Lymph Node Metastasis.

Background/aim: Vascular invasion (VI) in colorectal carcinoma (CRC) is an independent prognostic feature and a high-risk indicator for adjuvant chemotherapy in stage II CRC. This study evaluated the effect of elastic staining on VI detection.

Patients And Methods: The VI was assessed using elastic staining in 154 patients with CRC.

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.

Gradual telomere shortening in the tumorigenesis of pancreatic and hepatic mucinous cystic neoplasms.

Mucinous cystic neoplasm (MCN) is one of the precursor lesions of pancreatic ductal adenocarcinoma and intrahepatic cholangiocarcinoma. The aim of this study is to examine the presence of short telomeres in promoting the tumorigenesis of MCN by measuring telomere lengths in distinct components of MCN, including the mucinous lining epithelium, non-mucinous lining epithelium, and ovarian-type stroma. A total of 45 patients with MCN (30 pancreatic and 15 hepatic cases) were obtained.

Interpretable deep learning model to predict lymph node metastasis in early gastric cancer using whole slide images.

In early gastric cancer (EGC), the presence of lymph node metastasis (LNM) is a crucial factor for determining the treatment options. Endoscopic resection is used for treatment of EGC with minimal risk of LNM. However, owing to the lack of definitive criteria for identifying patients who require additional surgery, some patients undergo unnecessary additional surgery.

Oncocytic type has distinct immunohistochemical and recurrence-free survival than other histologic types of the intraductal papillary neoplasm of the bile duct.

Although intraductal oncocytic papillary neoplasm (IOPN) was considered distinct from the intraductal papillary neoplasm of the pancreas, the oncocytic histologic type remained as a subtype of intraductal papillary neoplasms of the bile duct (IPNBs) with gastric, intestinal, and pancreatobiliary types based on the fifth edition of the WHO classification. To test the characteristics of the oncocytic type of IPNBs, the histopathologic, immunohistochemical (Hep Par-1 and CD117), and clinical characteristics of 13 oncocytic type were compared with 114 others (15 gastric, 39 pancreatobiliary, and 60 intestinal) IPNB types. The oncocytic type, which occupied about 9% of IPNBs, was more frequent in females (p < 0.

Uncovering the clinicopathological features of early recurrence after surgical resection of pancreatic cancer.

To identify risk factors and biomarker for early recurrence in patients diagnosed with pancreatic cancer who undergo curative resection. Early recurrence after curative resection of pancreatic cancer is an obstacle to long-term survival. We retrospectively reviewed 162 patients diagnosed with pancreatic cancer who underwent curative resection.

Assessment of thyroid cartilage ossification pattern in cancer patients: A suggestion of active ossification by tumor progression.

Background: Ossified cartilage is much more susceptible to cancer infiltration, but the reason remains unknown, and the relationship between the ossification pattern and cancer infiltration has not been studied.

Methods: The presence of thyroid cartilage ossification, cancer infiltration, ossification pattern (usual: direction from inferior to superior; unusual: other than the usual pattern), and distance between cancer and ossified cartilage were evaluated in laryngectomy specimens.

Results: There were 28 and 27 cases of usual and unusual patterns, respectively.

Frequent Intraluminal Growth of Large Muscular Veins in Surgically Resected Colorectal Cancer Tissues: A 3-Dimensional Pathologic Reconstruction Study.

Although venous invasion (VI) is common in colorectal cancers (CRCs) and is associated with distant metastasis, the 3-dimensional (3D) microscopic features and associated mechanisms of VI are not well elucidated. To characterize the patterns of VI, 103 tissue slabs were harvested from surgically resected CRCs with ≥pT2. They were cleared using the modified immunolabeling-enabled 3D imaging of solvent-cleared organs method, labeled with multicolor fluorescent antibodies, including antibodies against cytokeratin 19, desmin, CD31, and E-cadherin, and visualized by confocal laser scanning microscopy.

p53 immunostaining pattern is a useful surrogate marker for TP53 gene mutations.

Background: TP53 is the most frequently mutated gene in the human cancer, and the awareness of its mutational status is useful in the diagnosis and treatment of cancer patients. In the present study, we investigated the association between TP53 gene mutations and p53 immunohistochemical staining (IHC) patterns and non-genetic effect of MDM2 as a negative regulator of p53.

Methods: A total of 135 solid cancer cases with next generation sequencing data were subjected to p53 IHC and classified as overexpression, null type or usual pattern.

High YAP and TEAD4 immunolabelings are associated with poor prognosis in patients with gallbladder cancer.

Yes-associated protein (YAP) and TEA domain-containing sequence-specific transcription factors 4 (TEAD4) are essential components of the Hippo pathway. Abnormal regulation of the Hippo pathway contributes to the progression and metastasis of many cancer types. However, their clinicopathologic and prognostic significances have not been studied in gallbladder cancers.

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.

Expression of HER2 and Mismatch Repair Proteins in Surgically Resected Gallbladder Adenocarcinoma.

Background: Gallbladder cancer (GBC) has a poor prognosis. Although complete surgical resection is the only successful approach for improving survival, additional therapeutic modalities are required for recurrent or surgically unresectable GBCs.

Materials And Methods: To determine the expression status of HER2 and the mismatch repair (MMR) proteins MLH1, MSH2, MSH6, and PMS2, immunohistochemical staining of MMR proteins and HER2 was carried out in 216 surgically resected GBCs.

Non-functional pancreatic neuroendocrine tumours: ATRX/DAXX and alternative lengthening of telomeres (ALT) are prognostically independent from ARX/PDX1 expression and tumour size.

Objective: Recent studies have found aristaless-related homeobox gene (ARX)/pancreatic and duodenal homeobox 1 (PDX1), alpha-thalassemia/mental retardation X-linked (ATRX)/death domain-associated protein (DAXX) and alternative lengthening of telomeres (ALT) to be promising prognostic biomarkers for non-functional pancreatic neuroendocrine tumours (NF-PanNETs). However, they have not been comprehensively evaluated, especially among small NF-PanNETs (≤2.0 cm).

Comprehensive histological evaluation with clinical analysis of venous invasion in pancreatic ductal adenocarcinoma: From histology to clinical implications.

Objectives: Venous invasion is a poor prognostic factor for pancreatic ductal adenocarcinoma (PDAC). However, our understanding of various features of venous invasion is limited. Our aim is to comprehensively evaluate various histopathologic features of venous invasion, including status, type (lymphatic or venous), number of invasion foci, and histologic pattern (pancreatic intraepithelial neoplasia [PanIN]-like, conventional) in PDACs.

Large tumor size, lymphovascular invasion, and synchronous metastasis are associated with the recurrence of solid pseudopapillary neoplasms of the pancreas.

Background: Solid pseudopapillary neoplasms (SPNs) of the pancreas have low malignant potential. However, malignant SPNs are not fully understood.

Methods: To evaluate risk factors affecting malignant potential, the clinicopathologic features of 375 surgically resected SPNs were compared.

Appendiceal actinomycosis mimicking appendiceal tumor, appendicitis or inflammatory bowel disease.

Appendiceal actinomycosis is very rare and its diagnosis is often difficult even in surgically resected specimens. Here we report two cases of appendiceal actinomycosis confirmed by pathologic examination of surgically resected specimens. Characteristic histologic features included transmural chronic inflammation with Crohn-like lymphoid aggregates and polypoid mucosal protrusion into cecal lumen through fibrous expansion of the submucosa.

Biliary intraductal tubule-forming neoplasm: a whole exome sequencing study of MUC5AC-positive and -negative cases.

Aims: Biliary intraductal tubular neoplasms that are non-mucinous and negative for mucin 5AC (MUC5AC) are called intraductal tubulopapillary neoplasms (ITPNs). Intraductal tubular neoplasms with mucinous cytoplasm and MUC5AC positivity also occur and their nature remains unclear, although some pathologists may classify these as 'intraductal papillary neoplasms of the bile duct (IPNBs) of gastric type'. This study aimed to elucidate genetic features of biliary intraductal tubular neoplasms.

Clinicopathologic and Prognostic Significance of Gallbladder and Cystic Duct Invasion in Distal Bile Duct Carcinoma.

Context.—: The roles of the gallbladder and cystic duct (CD) invasions in distal bile duct carcinoma (DBDC) have not been well elucidated.

Objective.

Validation of the 8th Edition of the American Joint Committee on Cancer Staging System for Gallbladder Cancer and Implications for the Follow-up of Patients without Node Dissection.

Purpose: The 8th edition of gallbladder cancer staging in the American Joint Committee on Cancer (AJCC) staging system changed the T and N categories.

Materials And Methods: In order to validate the new staging system, a total of 348 surgically resected gallbladder cancers were grouped based on the 8th edition of the T and N categories and compared with patients' survival.

Results: Significant differences were noted between T1b-T2a (p=0.

A Novel Blood-Based Colorectal Cancer Diagnostic Technology Using Electrical Detection of Colon Cancer Secreted Protein-2.

Colorectal cancer (CRC) is the second-leading cause of cancer-related mortality worldwide, which may be effectively reduced by early screening. Colon cancer secreted protein-2 (CCSP-2) is a promising blood marker for CRC. An electric-field effect colorectal sensor (E-FECS), an ion-sensitive field-effect transistor under dual gate operation with nanostructure is developed, to quantify CCSP-2 directly from patient blood samples.

Multiple KRAS mutations in the non-mucinous epithelial lining in the majority of mucinous cystic neoplasms of the pancreas.

Aims: Mucinous cystic neoplasms (MCNs) of the pancreas are cystic neoplasms lined by mucinous lining epithelium (MLE) with associated ovarian-type stroma. Although a non-MLE (NMLE) can be observed in some MCNs, whether cystic neoplasms with ovarian-type stroma and NMLE should be classified as MCNs or separately designated is debated.

Methods And Results: To test this, NMLEs were defined as flat or cuboidal epithelial cells without intracytoplasmic mucin.

IL-33 overexpression in gallbladder cancers associated with pancreatobiliary maljunction.

Aims: To investigate whether genetic or inflammatory pro-oncogenic factors are relevant to the increased risk of gallbladder cancers in patients with pancreaticobiliary maljunction (PBM).

Methods And Results: Mutations in KRAS exon 2 were examined by a highly sensitive, droplet digital PCR platform using surgically resected specimens of PBM-associated (n = 31) and non-associated gallbladder cancers (n = 49). The tissue expression of IL-6 and IL-33, which are suspected to promote biliary carcinogenesis, was analysed by quantitative real-time PCR and in-situ hybridisation.