Endocrine Abstracts

Introduction: Hypoglycemia is a rare clinical problem in patients not being treated for diabetes mellitus and requires further evaluation and management if Whipple’s triad is present. Insulinoma commonly presents with fasting hypoglycemia. Insulinoma is rarely associated with type 1 multiple endocrine neoplasia, when tumors are usually multiple and more frequently malignant. The diagnosis of insulinoma is established by demonstrating inappropriately high serum insulin concentrations during a spontaneous or induced episode of hypoglycemia, e.g. 72-h fast.

Patient: 46-years old female was referred to our department for evaluation of spontaneous fasting hypoglycemia. She had multiple episodes of temporary probably neurohypoglycemic symptoms (confusion, unusual behaviour) and gained a lot of weight in 2016 (+20 kg). Before the beginning of 72-h fast her serum glucose was 1.8 mmol/l, insulin concentration 20.6 mcU/ml, C-peptide 1.2 nmol/l. Testing was stopped after 6 h due to very low glucose levels (1.5 mmol/l) but without any obvious symptoms of hypoglycemia, insulin was high. After glucagone 1 mg i.v. glucose increased for 1.5 mmol/l. Her serum calcium, iPTH, prolactin and IGF-1 were normal. CT showed 1.8 cm lesion in the pancreatic neck and also unusual lesion in proximal jejunum that appeared to be a neuroendocrine tumor. There was also typical teratoma in left ovary (maximal size 6.6 cm), also seen on US. The patient underwent operation – partial pancreatectomy, proximal jejunal resection with anastomosis and left ovariectomy. Based on patohistology and imaging results benign insulinoma was confirmed, in jejunum there was ectopic pancreatic tissue, and there was mature teratoma of left ovary. We have not performed genetic testing for MEN1 since we thought it was unlikely. After operation, the patient was asymptomatic and normoglycemic.

Conclusions: We found three different tumors, including insulinoma, in a single patient. This combination has not yet been described to coincide and is not due to multiple endocrine neoplasia.