{"title":"Hypovascular insulinoma with reduced microvessel density on histopathology: a case report.","authors":"Risako Imai, Mayu Sakai, Takehiro Kato, Sayako Ozeki, Sodai Kubota, Yanyan Liu, Yoshihiro Takahashi, Ken Takao, Masami Mizuno, Takuo Hirota, Yukio Horikawa, Takaaki Murakami, Tomohiro Kanayama, Takahiro Kuroda, Tatsuhiko Miyazaki, Daisuke Yabe","doi":"10.1007/s13340-024-00756-z","DOIUrl":null,"url":null,"abstract":"<p><p>Pancreatic neuroendocrine tumors (PanNETs) are generally hypervascular and readily detectable on imaging tests. However, hypovascular PanNETs are clinically problematic, requiring multiple imaging tests and tissue analyses to differentiate them from pancreatic ductal cancers. A 41 year-old man presented with Whipple's triad; 72 h fasting test followed by glucagon challenge test suggested insulinoma. However, contrast-enhanced computed tomography image showed a 17 mm tumor with poor enhancement and unclear borders in the tail of the pancreas<i>.</i> Abdominal magnetic resonance imaging and contrast-enhanced endoscopic ultrasonography (EUS) indicated cystic degeneration and necrosis at the same site; EUS-guided fine-needle aspiration cytology indicated a PanNET Grade 1 tumor. Although the imaging was inconclusive, diazoxide treatment ameliorated the hypoglycemia-related symptoms and insulinoma was deemed likely; following tail pancreatectomy and splenectomy, the symptoms disappeared. Pathological examination revealed a tumor positive for insulin and classed as PanNET Grade 1 according to the 2019 WHO classification. The microvessel density (MVD) of the tumor was found to be as low as 3.9%, which may partly account for the inconclusive images. The present case was difficult to diagnose preoperatively due to hypovascularity on imaging because of reduced MVD. It is clinically important to evaluate MVD in cases of hypovascular PanNETs by multiple preoperative imaging studies to differentiate them from pancreatic cancers and to validate the findings by postoperative pathological analysis.</p>","PeriodicalId":11340,"journal":{"name":"Diabetology International","volume":null,"pages":null},"PeriodicalIF":1.3000,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11512940/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Diabetology International","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s13340-024-00756-z","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/10/1 0:00:00","PubModel":"eCollection","JCR":"Q4","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
引用次数: 0
Abstract
Pancreatic neuroendocrine tumors (PanNETs) are generally hypervascular and readily detectable on imaging tests. However, hypovascular PanNETs are clinically problematic, requiring multiple imaging tests and tissue analyses to differentiate them from pancreatic ductal cancers. A 41 year-old man presented with Whipple's triad; 72 h fasting test followed by glucagon challenge test suggested insulinoma. However, contrast-enhanced computed tomography image showed a 17 mm tumor with poor enhancement and unclear borders in the tail of the pancreas. Abdominal magnetic resonance imaging and contrast-enhanced endoscopic ultrasonography (EUS) indicated cystic degeneration and necrosis at the same site; EUS-guided fine-needle aspiration cytology indicated a PanNET Grade 1 tumor. Although the imaging was inconclusive, diazoxide treatment ameliorated the hypoglycemia-related symptoms and insulinoma was deemed likely; following tail pancreatectomy and splenectomy, the symptoms disappeared. Pathological examination revealed a tumor positive for insulin and classed as PanNET Grade 1 according to the 2019 WHO classification. The microvessel density (MVD) of the tumor was found to be as low as 3.9%, which may partly account for the inconclusive images. The present case was difficult to diagnose preoperatively due to hypovascularity on imaging because of reduced MVD. It is clinically important to evaluate MVD in cases of hypovascular PanNETs by multiple preoperative imaging studies to differentiate them from pancreatic cancers and to validate the findings by postoperative pathological analysis.
期刊介绍:
Diabetology International, the official journal of the Japan Diabetes Society, publishes original research articles about experimental research and clinical studies in diabetes and related areas. The journal also presents editorials, reviews, commentaries, reports of expert committees, and case reports on any aspect of diabetes. Diabetology International welcomes submissions from researchers, clinicians, and health professionals throughout the world who are interested in research, treatment, and care of patients with diabetes. All manuscripts are peer-reviewed to assure that high-quality information in the field of diabetes is made available to readers. Manuscripts are reviewed with due respect for the author''s confidentiality. At the same time, reviewers also have rights to confidentiality, which are respected by the editors. The journal follows a single-blind review procedure, where the reviewers are aware of the names and affiliations of the authors, but the reviewer reports provided to authors are anonymous. Single-blind peer review is the traditional model of peer review that many reviewers are comfortable with, and it facilitates a dispassionate critique of a manuscript.