{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T01:09:22Z","timestamp":1790730562302,"version":"4.1.0"},"reference-count":0,"publisher":"Bioscientifica","license":[{"start":{"date-parts":[[2021,4,1]],"date-time":"2021-04-01T00:00:00Z","timestamp":1617235200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["edm.bioscientifica.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2021,4,1]]},"abstract":"\n Summary<\/jats:title>\n \n A 38-year-old female was identified as carrying a heterozygous pathogenic\n MEN1<\/jats:italic>\n variant (c.1304delG) through predictive genetic testing, following a diagnosis of familial hyperparathyroidism. Routine screening for parathyroid and pituitary disease was negative. However, cross-sectional imaging by CT revealed a 41 mm pancreatic tail mass. Biopsy via endoscopic ultrasound confirmed the lesion to be a well-differentiated (grade 1) pancreatic neuroendocrine tumour (pNET) with MIB1<1%. Biochemically, hyperinsulinaemic hypoglycaemia was confirmed following an overnight fast, which was subsequently managed by diet alone prior to definitive surgery. Pre-operative work-up with octreotide SPECT CT demonstrated avid tracer uptake in the pancreatic lesion and, unexpectedly, a focal area of uptake in the left breast. Further investigation, and subsequent mastectomy, confirmed ductal carcinoma\n in situ<\/jats:italic>\n pT2 (23 mm) grade 1, N0 (ER positive; HER2 negative). Following mastectomy, our patient underwent a successful distal pancreatectomy to resect the pNET. Loss of heterozygosity (LOH) at the\n MEN1<\/jats:italic>\n locus was found in both the breast tumour and pNET, thereby in keeping with a 'two-hit' hypothesis of oncogenesis, a suggestive but non-definitive clue for causation. To obtain further support for a causative relationship between MEN1 and breast cancer, we undertook a detailed review of the published literature which overall supports the notion that breast cancer is a\n MEN1<\/jats:italic>\n -related malignancy that presents at a younger age and histologically, is typically of ductal subtype. Currently, clinical guidance regarding breast cancer surveillance in MEN1 does not exist and further research is required to establish a clinical and cost-effective surveillance strategy).\n <\/jats:p>\n <\/jats:sec>\n \n Learning points<\/jats:title>\n \n \n \n We describe a case of pNET and breast cancer diagnosed at a young age of 38 years in a patient who is heterozygous for a pathogenic\n MEN1<\/jats:italic>\n variant. Loss of the wild-type allele was seen in both breast tissue and pNET specimen.\n <\/jats:p>\n <\/jats:list-item>\n \n \n Breast cancer may be an under-recognised\n MEN1<\/jats:italic>\n -associated malignancy that presents at a younger age than in the general population with a relative risk of 2\u20133.\n <\/jats:p>\n <\/jats:list-item>\n \n Further research is required to determine the cost-effectiveness of breast cancer surveillance approach at a younger age in MEN1 patients relative to the general population \n.<\/jats:p>\n <\/jats:list-item>\n <\/jats:list>\n <\/jats:sec>","DOI":"10.1530\/edm-20-0196","type":"journal-article","created":{"date-parts":[[2021,5,7]],"date-time":"2021-05-07T06:15:46Z","timestamp":1620368146000},"update-policy":"https:\/\/doi.org\/10.1530\/crossmarkpolicy-2","source":"Crossref","is-referenced-by-count":4,"title":["Breast cancer in multiple endocrine neoplasia type 1 (MEN1)"],"prefix":"10.1530","volume":"2021","author":[{"given":"Seong Keat","family":"Cheah","sequence":"first","affiliation":[{"name":"1Endocrinology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chad Ramese","family":"Bisambar","sequence":"additional","affiliation":[{"name":"1Endocrinology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deborah","family":"Pitfield","sequence":"additional","affiliation":[{"name":"1Endocrinology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Olivier","family":"Giger","sequence":"additional","affiliation":[{"name":"2Pathology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rogier ten","family":"Hoopen","sequence":"additional","affiliation":[{"name":"2Pathology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jose-Ezequiel","family":"Martin","sequence":"additional","affiliation":[{"name":"3Medical Genetics, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Graeme R","family":"Clark","sequence":"additional","affiliation":[{"name":"3Medical Genetics, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Soo-Mi","family":"Park","sequence":"additional","affiliation":[{"name":"3Medical Genetics, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Craig","family":"Parkinson","sequence":"additional","affiliation":[{"name":"4Endocrinology, East Suffolk and North Essex NHS Foundation Trust, Colchester, Essex, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benjamin G","family":"Challis","sequence":"additional","affiliation":[{"name":"1Endocrinology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruth T","family":"Casey","sequence":"additional","affiliation":[{"name":"1Endocrinology, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"},{"name":"3Medical Genetics, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"416","container-title":["Endocrinology, Diabetes & Metabolism Case Reports"],"original-title":[],"link":[{"URL":"https:\/\/edm.bioscientifica.com\/view\/journals\/edm\/2021\/1\/EDM20-0196.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/edm.bioscientifica.com\/downloadpdf\/journals\/edm\/2021\/1\/EDM20-0196.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T13:47:32Z","timestamp":1784555252000},"score":1,"resource":{"primary":{"URL":"http:\/\/journals.bioscientifica.com\/edm\/article\/3195"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,1]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1530\/edm-20-0196","relation":{},"ISSN":["2052-0573"],"issn-type":[{"value":"2052-0573","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,1]]}}}