Pancreatic medullary carcinoma developed on a pancreatic intraductal papillary mucinous neoplasm with loss of MSH2 and MSH6 expression: a case report

Diagnostic Pathology

卷:16

Dominique Bafort¹  Gloria Butorano¹  Jean-Luc Van Laethem²  Marc Witterwulghe³  Julie Navez⁴  Jean Closset⁴  Calliope Maris⁵  Camille Verocq⁵  Nicky D’Haene⁵  Marie-Lucie Racu⁵  Luis Perez-Casanova Garcia⁵  Niall Swan⁶  Kieran Sheahan⁶ 

[1] Centre Universitaire Inter Régional d’Expertise en Anatomie Pathologique Hospitalière (CurePath);

[2] Department of Gastroenterology and Digestive oncology, Erasme University Hospital, Université Libre de Bruxelles;

[3] Department of Gastroenterology, CHIREC Hospitals;

[4] Department of Hepato-Biliary-Pancreatic Surgery, Erasme University Hospital, Université Libre de Bruxelles;

[5] Department of Pathology, Erasme Hospital, Université Libre de Bruxelles (ULB);

[6] Department of Pathology, UCD School of Medicine, St Vincent’s University Hospital;

关键词: Pancreatic medullary carcinoma;    Intraductal papillary mucinous neoplasm;    IPMN;    Microsatellite instability;    Case report;   

DOI  :  10.1186/s13000-021-01178-0

来源: DOAJ

【 摘 要 】

Abstract Background Pancreatic medullary carcinoma (PMC) is a rare pancreatic tumor, usually showing the presence of microsatellite instability, mostly MLH1 silencing, and a wild-type KRAS mutation status. We report here a PMC arising from a Pancreatic Intraductal Papillary Mucinous Neoplasm (IPMN), both having KRAS and TP53 mutations. Case presentation We report the case of a 73-year-old woman presenting with right iliac fossa pain. MRI revealed a 16 mm diameter mass in the pancreas, leading to a pancreatic duct stricture and upstream a dilatation of the distal pancreatic duct of Wirsung. A fine needle aspiration was performed, and pathology analysis revealed malignant glandular cells. The patient underwent distal pancreatectomy. Gross examination revealed an12 mm indurated white lesion, adjacent to a cystic lesion extending into the rest of the pancreatic body. Microscopically, the cystic area represented a mixed (gastric-type and pancreatobiliary-type) IPMN, involving the main and secondary pancreatic ducts with low-grade and high-grade dysplasia. In the periphery of this IPMN, a 14mm associated invasive carcinoma was observed, characterized by focal gland formation and by poorly differentiated cells with a syncytial appearance, associated with a dense lymphoplasmocytic and neutrophilic infiltrate. Immunohistochemical analyses showed loss of MSH2 and MSH6 expression. Microsatellite instability was confirmed by molecular test. Molecular analysis was performed both on the invasive carcinoma and on the high-grade dysplasia IPMN, revealing the same mutation profile with KRAS and TP53 mutations. The proposed diagnosis was mixed IPMN with associated invasive medullary carcinoma that presented loss of MSH2 and MSH6 expression. Conclusions The present case reports for the first time, at the best of our knowledge, the coexistence of IPMN lesions and PMC, both having the same molecular alterations. It also describes the second case of PMC with microsatellite instability, MSH2 and MSH6 silenced.

【 授权许可】

Unknown