Abstract #1397268: A Rare Case of Insulinomatosis in a 58-Year-Old Woman with Recurrent Symptoms of Hypoglycemia

Abstract

Insulinomatosis is a rare cause of hyperinsulinaemic hypoglycaemia. The ideal management approach is not known. We present a case of recurrent hypoglycemia whose management was complicated by the pandemic. A 58-year-old woman with a family history of a mother who died of a pancreatic tumor and a personal history of congenital bilateral cataract, arterial hypertension, subclinical hypothyroidism, Child A liver cirrhosis, and subtotal pancreatectomy for hyperinsulinemic hypoglycemia in 2019 due to two insulinomas in the head and body of the pancreas. The pathological and immunohistochemical study was consistent with two pancreatic neuroendocrine tumors with Ki67: 1%, we did not have staining for insulin. She was discharged without episodes of hypoglycemia; 10 months after the operation, she presented a recurrence of neuroglycopenic symptoms during periods of fasting, which she controlled with a greater intake of food; furthermore, she recorded fasting capillary glycemia between 40-60mg/dl without symptoms. Due to the pandemic, she could not be evaluated at our center until 2022, when she was hospitalized for study. Hyperinsulinemic hypoglycemia was verified, imaging studies (CT, MRI, PET) did not show lesions in the remaining pancreatic tissue; On its own, endoscopic echocardiography described a 7-mm lesion adjacent to the splenic artery. The patient did not accept new surgery. The genetic study for MEN type 1 was negative. The subcutaneous octreotide test showed a glycemia value greater than 100mg/dL after its administration, so she was discharged with a fractionated diet and subcutaneous octreotide 25-50 ug at night. To date, she has not presented a clinical picture again. and biochemical hypoglycemia with adequate tolerance. Insulinomas are the most frequent pNETs (45%). About 10% are multiple, 10% are malignant, and 16% are associated with MEN1. Insulinomas are usually benign and managed surgically. Insulinomas that appear synchronously or metachronously, but are not associated with MEN1 are termed insulinomatosis. Diagnosis consists of documentation of hyperinsulinemic hypoglycemia, synchronous presence of β-cell micro- or macrotumors, or early recurrence of hyperinsulinemic hypoglycemia with new β-cell lesion in a history of prior insulinoma. Insulinomatosis is distinguished histologically by insulin-expressing monohormonal endocrine cell clusters (IMECCs) and tumor staining only for insulin, whereas MEN-1 associated insulinomas stain for multiple hormones. Regarding management, the first line is surgery, although in some cases total pancreatectomy did not result in a cure for hypoglycemia, so local or systemic treatment can be used (diazoxide, corticosteroids, somatostatin analogues, verapamil, and everolimus).