{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,16]],"date-time":"2026-05-16T21:33:14Z","timestamp":1778967194447,"version":"3.51.4"},"reference-count":13,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,9,29]],"date-time":"2021-09-29T00:00:00Z","timestamp":1632873600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2021,9,29]],"date-time":"2021-09-29T00:00:00Z","timestamp":1632873600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Med Case Reports"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Background<\/jats:title>\n                <jats:p>Insulinomas are rare clinical entities, but concurrent diabetes mellitus is even more uncommon, and the combination is easily missed. Recurrent hypoglycemia could be misconstrued as improved glycemic control. We present an unusual patient with type 2 diabetes and neuroglycopenia, with apparent improved glycemic control due to an insulinoma.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Case presentation<\/jats:title>\n                <jats:p>A 54-year-old mixed ancestry man with a positive family history of type 2 diabetes mellitus was diagnosed with type 2 diabetes mellitus and hypertension 8\u00a0years prior to admission. He presented with episodes of abnormal behavior and hypoglycemia. Inappropriately high insulin and C-peptide concentrations were identified at the time of hypoglycemia. Despite poor adherence to his diabetic treatment, he had no target organ damage relating to diabetes, and his hemoglobin A1c (HbA1c) was 5.3%. A diagnosis of insulinoma was made, and he was started on diazoxide, with endoscopic ultrasound revealing a possible lesion in the pancreatic tail measuring 12\u00a0mm \u00d7 12\u00a0mm. A fine-needle aspiration biopsy could not be performed due to overlying splenic arteries and the risk of vascular perforation. An intraoperative ultrasound confirmed a 15\u00a0mm \u00d7 10\u00a0mm tumor in the pancreatic tail, necessitating a partial pancreatectomy and splenectomy, which were curative. A well-differentiated intermediate grade 2 pancreatic neuroendocrine tumor producing insulin was confirmed on histopathology.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>Recurrent, progressive hypoglycemia and improved glycemic control in a diabetic, without an alternative explanation, may suggest an insulinoma. Insulinomas that exist with type 1 diabetes mellitus, particularly malignant insulinomas, must have escaped autoimmune attack through lack of autoantigen expression. Computed tomography on its own may be insufficiently sensitive for diagnosis of insulinomas, whereas endoscopic and intraoperative ultrasonography may improve the identification of the culprit lesion.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s13256-021-03047-2","type":"journal-article","created":{"date-parts":[[2021,9,28]],"date-time":"2021-09-28T23:06:38Z","timestamp":1632870398000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Challenge of coexisting type 2 diabetes mellitus and insulinoma: a case report"],"prefix":"10.1186","volume":"15","author":[{"given":"Joseph","family":"Singbo","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Locketz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ian Louis","family":"Ross","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2021,9,29]]},"reference":[{"issue":"1","key":"3047_CR1","doi-asserted-by":"publisher","first-page":"e39439","DOI":"10.5812\/ijem.39439","volume":"15","author":"K Ouleghzal","year":"2016","unstructured":"Ouleghzal K, Ziadi T, Menfaa M, Safia S. Association of insulinoma and type 2 diabetes mellitus. Int J Endocrinol Metab. 2016;15(1):e39439.","journal-title":"Int J Endocrinol Metab"},{"key":"3047_CR2","doi-asserted-by":"publisher","first-page":"1038","DOI":"10.4158\/EP12082.LT","volume":"18","author":"T Kunieda","year":"2012","unstructured":"Kunieda T, Yamakita N, Yasuda K. Insulinoma in a patient with type 2 diabetes mellitus proved at autopsy. Endocr Pract. 2012;18:1038.","journal-title":"Endocr Pract"},{"key":"3047_CR3","doi-asserted-by":"publisher","first-page":"375","DOI":"10.1007\/s13300-019-0563-0","volume":"10","author":"M Nunez","year":"2019","unstructured":"Nunez M, D\u0131az S, Dilla T, Reviriego J, Perez A. Epidemiology, quality of life, and costs associated with hypoglycemia in patients with diabetes in Spain: a systematic literature review. Diabetes Ther. 2019;10:375\u201392. https:\/\/doi.org\/10.1007\/s13300-019-0563-0.","journal-title":"Diabetes Ther"},{"key":"3047_CR4","doi-asserted-by":"publisher","first-page":"1298","DOI":"10.2337\/diacare.16.9.1298","volume":"16","author":"LA Kane","year":"1993","unstructured":"Kane LA, Grant CS, Nippoldt TB, Service FJ. Insulinoma in a patient with NIDDM. Diabetes Care. 1993;16:1298\u2013300.","journal-title":"Diabetes Care"},{"issue":"Suppl","key":"3047_CR5","first-page":"199","volume":"51","author":"H Ishii","year":"1993","unstructured":"Ishii H, Ito T, Moriya S, Horie Y, Tsuchiya M. Insulinoma\u2013a statistical review of 443 cases in Japan. Nihon Rinsho. 1993;51(Suppl):199\u2013206.","journal-title":"Nihon Rinsho"},{"key":"3047_CR6","doi-asserted-by":"publisher","first-page":"392","DOI":"10.1016\/S0929-6646(09)60324-7","volume":"106","author":"WY Lei","year":"2007","unstructured":"Lei WY, Wang TE, Chen TL, Chang WH, Yang TL, Wang CY. Insulinoma causing hypoglycemia in a patient with type 2 diabetes. J Formos Med Assoc. 2007;106:392\u20136.","journal-title":"J Formos Med Assoc"},{"key":"3047_CR7","doi-asserted-by":"publisher","first-page":"e138","DOI":"10.1111\/j.1464-5491.2012.03615.x","volume":"29","author":"Y Oikawa","year":"2012","unstructured":"Oikawa Y, Katsuki T, Kawasaki M, Hashiguchi A, Mukai K, Handa K, Tomita M, Kabeya Y, Asai Y, Iwase K, et al. Insulinoma may mask the existence of type 1 diabetes. Diabet Med. 2012;29:e138-141.","journal-title":"Diabet Med"},{"key":"3047_CR8","doi-asserted-by":"publisher","first-page":"761","DOI":"10.1002\/ccr3.927","volume":"5","author":"HK Gjelberg","year":"2017","unstructured":"Gjelberg HK, Hoem D, Verbeke CS, Eide J, Cooper JG, Molven A. Hypoglycemia and decreased insulin requirement caused by malignant insulinoma in a type 1 diabetic patient: when the hoof beats are from a zebra, not a horse. Clin Case Rep. 2017;5:761\u20138.","journal-title":"Clin Case Rep"},{"key":"3047_CR9","first-page":"211","volume":"31","author":"JT Priestley","year":"1962","unstructured":"Priestley JT. Hyperinsulinism. Ann R Coll Surg Engl. 1962;31:211\u201328.","journal-title":"Ann R Coll Surg Engl"},{"key":"3047_CR10","doi-asserted-by":"publisher","first-page":"E133","DOI":"10.1111\/j.1464-5491.2012.03603.x","volume":"29","author":"E Ademoglu","year":"2012","unstructured":"Ademoglu E, Unluturk U, Agbaht K, Karabork A, Corapcioglu D. Type 2 diabetes mellitus in a patient with malignant insulinoma manifesting following surgery. Diabet Med. 2012;29:E133\u20137.","journal-title":"Diabet Med"},{"key":"3047_CR11","doi-asserted-by":"publisher","first-page":"829","DOI":"10.3748\/wjg.v19.i6.829","volume":"19","author":"T Okabayashi","year":"2013","unstructured":"Okabayashi T, Shima Y, Sumiyoshi T, Kozuki A, Ito S, Ogawa Y, Kobayashi M, Hanazaki K. Diagnosis and management of insulinoma. World J Gastroenterol. 2013;19:829\u201337.","journal-title":"World J Gastroenterol"},{"key":"3047_CR12","doi-asserted-by":"publisher","first-page":"264","DOI":"10.1002\/cncr.21179","volume":"104","author":"B Hirshberg","year":"2005","unstructured":"Hirshberg B, Cochran C, Skarulis MC, Libutti SK, Alexander HR, Wood BJ, Chang R, Kleiner DE, Gorden P. Malignant insulinoma: spectrum of unusual clinical features. Cancer. 2005;104:264\u201372.","journal-title":"Cancer"},{"key":"3047_CR13","doi-asserted-by":"publisher","first-page":"68","DOI":"10.1055\/s-0031-1287792","volume":"120","author":"A Jawiarczyk","year":"2012","unstructured":"Jawiarczyk A, Bolanowski M, Syrycka J, Bednarek-Tupikowska G, Kaluzny M, Kolodziejski A, Domoslawski P. Effective therapy of insulinoma by using long-acting somatostatin analogue. A case report and literature review. Exp Clin Endocrinol Diabetes. 2012;120:68\u201372.","journal-title":"Exp Clin Endocrinol Diabetes"}],"container-title":["Journal of Medical Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s13256-021-03047-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s13256-021-03047-2\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s13256-021-03047-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,9,28]],"date-time":"2021-09-28T23:51:02Z","timestamp":1632873062000},"score":1,"resource":{"primary":{"URL":"https:\/\/jmedicalcasereports.biomedcentral.com\/articles\/10.1186\/s13256-021-03047-2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,29]]},"references-count":13,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2021,12]]}},"alternative-id":["3047"],"URL":"https:\/\/doi.org\/10.1186\/s13256-021-03047-2","relation":{},"ISSN":["1752-1947"],"issn-type":[{"value":"1752-1947","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,9,29]]},"assertion":[{"value":"13 May 2020","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"5 August 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"29 September 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The Faculty of Health Sciences Research and Ethics Committee at the University of Cape Town waives ethics submissions for case reports.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"All the authors have no competing interests, whatsoever.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"479"}}