{"title":"Proposal for a New Classification of Rare Cancers Adopting Updated Histological Tumor Types.","authors":"Ryoko Rikitake, Yasushi Yatabe, Yoko Yamamoto, Tatsunori Shimoi, Shintaro Iwata, Yasushi Goto, Yu Mizushima, Akira Kawai, Takahiro Higashi","doi":"10.1111/pin.70021","DOIUrl":"10.1111/pin.70021","url":null,"abstract":"<p><p>Several classifications have been proposed to define rare cancers; however, the pathophysiological understanding of tumors evolves rapidly. We propose a New Classification of Rare Cancer (NCRC) using the updated International Classification of Diseases for Oncology 3.2 coding system and World Health Organization Classification of Tumors 5th edition. We applied patient data recorded in the National Cancer Registry of Japan to the new classification, setting a cut-off of a crude incidence rate of 6 cases/100 000/year to define rare cancers, and developed a list of rare cancers in Japan from 2016 to 2019. The NCRC system identified various rare cancers, comprising 20.0% of all cancer diagnoses in this period. To examine this classification system's performance, we compared rare/non-rare labeling of cancers by the Surveillance of Rare Cancers in Europe (RARECARENet) project and NCRC system. Compared with cases using the RARECARENet classification in Europe, 69 351 cases/year (6.8%) switched status with our classification, with 45 293 and 232 109 cases (4 years) switching from rare and non-rare, respectively. Major differences included diffuse large B-cell lymphomas, some thyroid cancers, oral cavity and lip cancers, and squamous cell carcinoma of the uterine cervix. As the NCRC includes newly classified tumor entities, it warrants validation using other diverse cohorts.</p>","PeriodicalId":19806,"journal":{"name":"Pathology International","volume":" ","pages":"291-309"},"PeriodicalIF":2.5,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12184288/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144079458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cmtm4 Deficiency Inhibits Helicobacter pylori-Induced Gastric Carcinogenesis.","authors":"Yanfei Lang, Xiurui Han, Xin Liu, Jing Ning, Xinyu Hao, Hejun Zhang, Jing Zhang, Kangle Zhai, Jing Zhang, Weiwei Fu, Shigang Ding","doi":"10.1111/pin.70020","DOIUrl":"10.1111/pin.70020","url":null,"abstract":"<p><p>Helicobacter pylori is the main pathogenic factor in gastric cancer (GC), and the interleukin (IL)-17-mediated inflammatory response plays a crucial role in both H. pylori infection and gastric carcinogenesis. CMTM4, a subunit of the IL-17 receptor (IL-17R), has been implicated in immune responses, but its role in GC development remains unclear. In this study, we investigate the role of CMTM4 during H. pylori-induced gastric carcinogenesis using Cmtm4 knockout (KO) mice. Our findings indicated that Cmtm4 deficiency inhibited GC development and pseudopyloric metaplasia, while reducing DNA damage in the gastric mucosa. Mechanistically, Cmtm4 deletion downregulated the IL-17 signaling pathway in GC. Specifically, it suppressed the expression of IL-17 receptor RC (IL-17RC) and its downstream signaling molecules, resulting in the inhibition of nuclear factor-κ B (NF-κB) activation and a decrease in NADPH oxidase-1 (NOX1) levels. These results suggest that Cmtm4 deletion suppresses H. pylori-induced gastric carcinogenesis and precancerous lesion formation, potentially through the regulation of IL-17RC/NF-κB/NOX1 signaling, which may represent a new target for the early prevention of GC.</p>","PeriodicalId":19806,"journal":{"name":"Pathology International","volume":" ","pages":"278-290"},"PeriodicalIF":2.5,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144161019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lars Egevad, Andrea Camilloni, Brett Delahunt, Hemamali Samaratunga, Martin Eklund, Kimmo Kartasalo
{"title":"The Role of Artificial Intelligence in the Evaluation of Prostate Pathology.","authors":"Lars Egevad, Andrea Camilloni, Brett Delahunt, Hemamali Samaratunga, Martin Eklund, Kimmo Kartasalo","doi":"10.1111/pin.70015","DOIUrl":"10.1111/pin.70015","url":null,"abstract":"<p><p>Artificial intelligence (AI) is an emerging tool in diagnostic pathology, including prostate pathology. This review summarizes the possibilities offered by AI and also discusses the challenges and risks. AI has the potential to assist in the diagnosis and grading of prostate cancer. Diagnostic safety can be enhanced by avoiding the accidental underdiagnosis of small lesions. Another possible benefit is a greater degree of standardization of grading. AI for clinical use needs to be trained on large, high-quality data sets that have been assessed by experienced pathologists. A problem with the use of AI in prostate pathology is the plethora of benign mimics of prostate cancer and morphological variants of cancer that are too unusual to allow sufficient training of AI. AI systems need to be able to account for variations in local routines for cutting, staining, and scanning of slides. We also need to be aware of the risk that users will rely too much on the output of an AI system, leading to diagnostic errors and loss of clinical competence. The reporting pathologist must ultimately be responsible for accepting or rejecting the diagnosis proposed by AI.</p>","PeriodicalId":19806,"journal":{"name":"Pathology International","volume":" ","pages":"213-220"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12101047/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144047406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nemaline bodies are not always congenital: A case of sporadic late-onset nemaline myopathy (SLONM) with monoclonal gammopathy of undetermined significance (MGUS).","authors":"Silvie Thomas, Deepti Narasimhaiah, Sruthi S Nair, Bejoy Thomas, Rashmi Santhoshkumar, Anita Mahadevan, Rajalakshmi Poyuran","doi":"10.1111/pin.70000","DOIUrl":"10.1111/pin.70000","url":null,"abstract":"","PeriodicalId":19806,"journal":{"name":"Pathology International","volume":" ","pages":"247-250"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143080661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shunsuke Koga, Wei Du, Gabriel C Caponetti, Kumarasen Cooper
{"title":"Follicular Dendritic Cell Sarcoma of the Parapharyngeal Space Arising in Association With Castleman Disease.","authors":"Shunsuke Koga, Wei Du, Gabriel C Caponetti, Kumarasen Cooper","doi":"10.1111/pin.70007","DOIUrl":"10.1111/pin.70007","url":null,"abstract":"<p><p>Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm of follicular dendritic cell origin. It is occasionally associated with unicentric Castleman disease (UCD), particularly the hyaline-vascular (HV) variant (HV-UCD). We report a 56-year-old woman with FDCS arising in the parapharyngeal space in the background of HV-UCD. The patient presented with a painless right neck mass and extensive cervical lymphadenopathy without systemic symptoms. Surgical resection of the parapharyngeal mass revealed FDCS in the lymph nodes with features of HV-UCD. Immunohistochemistry confirmed the follicular dendritic cell lineage of the lesional cells, with positivity for CD21 and CD23. Subsequent lymph node dissection from levels 2A, 2B, 3, and 4 showed features of HV-UCD without residual FDCS. This case highlights the diagnostic challenge FDCS represents, particularly when arising in an unusual location. While complete surgical excision remains the standard of care, long-term follow-up is necessary to monitor for recurrence or metastasis.</p>","PeriodicalId":19806,"journal":{"name":"Pathology International","volume":" ","pages":"236-242"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12101044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143764341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Potential Case of Tubulocystic Ductal Carcinoma of the Pancreas.","authors":"Rena Uno, Yoh Zen, Tomonori Tanaka, Hirochika Toyama, Takumi Fukumoto, Keitaro Sofue, Tomoo Itoh","doi":"10.1111/pin.70008","DOIUrl":"10.1111/pin.70008","url":null,"abstract":"<p><p>We present a case of pancreatic ductal carcinoma with a microcystic appearance. A 64-year-old woman was found to have a pancreatic mass during a routine medical checkup. The tumor was well-circumscribed and multicystic; thus, she was followed up for suspected serous cystadenoma. However, the tumor gradually enlarged in the following 2.5 years; subsequently, she underwent a Whipple procedure. Grossly, the cut surface of the tumor was honeycomb-like with small cysts. Histologically, the cysts were ductal structures lined by a relatively bland, cuboidal or columnar epithelium with mildly enlarged nuclei. No intracytoplasmic mucus was observed. The presence of stromal invasion confirmed the diagnosis of ductal carcinoma. KRAS was wild type. Postoperative course was uneventful, with no recurrence to date (followup period: 5.5 years postsurgery). The present case did not meet any known subtypes of pancreatic ductal carcinoma. The tumor resembled a large duct variant, which typically shows a microcystic appearance. However, unlike the present case, the large duct type usually consists of mucus-rich neoplastic cells. A recent study on cholangiocarcinoma proposed a novel tubulocystic subtype characterized by microcystic neoplastic glands and adenofibromatous stroma, which is morphologically similar to the present case. The present case may correspond to a pancreatic counterpart of tubulocystic cholangiocarcinoma.</p>","PeriodicalId":19806,"journal":{"name":"Pathology International","volume":" ","pages":"243-246"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144006940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}