Insulinoma diagnosed in the postpartum: clinical and immunohistochemical features

Abstract

Insulinomas are rare pancreatic β-cell tumors with an estimated incidence of 1:250.000 persons/year. We present a novel case of insulinoma manifesting immediately after childbirth. Eight days after delivery, a 21-year-old, previously healthy woman presented paresthesia in hands, upper and lower limbs muscle weakness with difficult walking, which worsened during breastfeeding sessions. Laboratory tests showed blood glucose levels between 37 and 55 mg/dL with inappropriately normal insulin levels (7.78 μUI/mL; normal range: 5-29). An abdominal computed tomography showed a nodular lesion measuring 2 cm at the head of the pancreas. Tumor enucleation resulted in complete resolution of hypoglycemia. Histopathological and immunohistochemical analysis were consistent with an insulinoma. About 27 cases of insulinoma associated with pregnancy have been reported to date, mostly diagnosed before the 16th week. The beginning of symptoms soon after delivery is less common. Understanding the interactions between pancreatic β-cell function and all the physiological metabolic and hormonal adaptations associated with gestation is essential for the adequate management of hypoglycemic disorders in pregnant women.

Insulinoma as rare cause of severe post‐partum hypoglycemia

“…To date, there have been fewer than 10 published comparable descriptions of insulinomas unmasking postpartum with onset of preponderant neuroglycopenic symptoms from 12 h to 3 months after delivery. [3][4][5][6][7][8][9][10][11] Consistent with these cases, our patient also demonstrated the typical Whipple's triad: 1 hypoglycemia with neuroglycopenic symptoms being documented by plasma glucose concentrations of <30 mg/dL and complete resolution of symptoms after normalization of blood glucose. Furthermore, critical diagnostic findings of inappropriate high plasma insulin and C-peptide concentrations during hypoglycemia were proven.…”

Hypoglycemia identified by a continuous glucose monitoring system in a second-trimester pregnant woman with insulinoma: a case report

“…In some cases, a conservative approach might be advised until delivery, to proceed to definitive surgical treatment preceded by tumor localization, after the end of pregnancy [10, 13]. In our case, surgical exploration at 21 weeks of gestation confirmed the preoperative localization and the tumor was completely removed by distal pancreatectomy.…”

“…This might be explained due to different insulin sensitivity in the course of pregnancy. Frequent meals and intravenously administered glucose infusions were adequate for hypoglycemia control in most of the cases, and only a small number of patients were operated at weeks 12 to 17 of gestation [10]. …”

Intractable hypoglycemia in pregnancy

“…4 Evidence based management is very limited hence decisions on investigation and therapy must be individualized and undertaken jointly by the multidisciplinary medical team and the patient. 3,5 The optimal strategy will depend on the nature and stage of the endocrine tumor, gestational age, treatments available and patient's wishes. There is good evidence that insulin secretion increases rapidly from the beginning of pregnancy because of beta cell proliferation and enhanced beta cell sensitivity to glucose stimulus as a result of hormonal changes.…”

“…1,2 About 27 cases of insulinoma associated with pregnancy have been reported to date, mostly diagnosed before the 16th week. 3 More than 80% are solitary benign tumors and small (<2 cm), often difficult to localize, have an indolent course and 5% may be malignant with liver and lymph node metastasis.…”