Ectopic insulinomas in the pelvis secondary to rectum neuroendocrine tumour

Ectopic insulinoma: a systematic review

Knowledge of ectopic insulinomas comes from single cases. We performed a systematic review through PubMed, Web of Science, Embase, eLibrary and ScienceDirect of all cases reported in the last four decades. We also describe one unreported patient. From 28 patients with ectopic insulinoma, 78.6% were female and mean age was 55.7 ± 19.2 years. Hypoglycaemia was the first symptom in 85.7% while 14.3% complained of abdominal pain or genital symptoms. Median tumour diameter was 27.5 [15-52.5] mm and it was localised by CT (73.1%), MRI (88.9%), [68Ga]Ga-DOTA-exedin-4 PET/CT (100%), 68Ga-labelled-DOTA-conjugated somatostatin analogue PET/TC (100%), somatostatin receptor scintigraphy (40%) and endoscopic ultrasound (50%). Ectopic insulinomas were located at duodenum (n = 3), jejunum (n = 2), and one respectively at stomach, liver, appendix, rectum, mesentery, ligament of Treitz, gastrosplenic ligament, hepatoduodenal ligament and splenic hilum. Seven insulinomas were affecting the female reproductive organs: ovary (n = 5), cervix (n = 2) and remaining tumours were at retroperitoneum (n = 3), kidney (n = 2), spleen (n = 1) and pelvis (n = 1). 89.3% underwent surgery (66.7% surgery vs. 33.3% laparoscopy) and 16% underwent an ineffective pancreatectomy. 85.7% had localized disease at diagnosis and 14.3% developed distant metastasis. Median follow-up time was 14.5 [4.5-35.5] months and mortality was reported in 28.6% with median time until death of 60 [5-144] months. In conclusion, ectopic insulinomas are presented as hypoglycaemia with female preponderance. Functional imaging [68Ga]Ga-DOTA-exedin-4 PET/CT and 68Ga-labelled-DOTA-conjugated somatostatin analogue PET/TC have very high sensitivity. Clinicians should be alert to the possibility of extra-pancreatic insulinomas when classic diagnostic tests and intraoperative pancreas exploration failed to locate the tumour.

A case report on a protracted course of a hidden insulinoma

Introduction

Insulinoma is a functioning pancreatic neuroendocrine tumor primarily leading due to hypoglycemia due to hypersecretion of insulin. This case illustrates the real challenges faced in the detection of an occult insulinoma, which resulted in a protracted course of the disease.

Case presentation

A 33-year-old female presented with recurrent hypoglycemia. Endogenous hyperinsulinemia was confirmed by a prolonged fast, however serial imaging was negative. Incidental finding of an ovarian mass gave rise to the suspicion of an insulin-producing ovarian tumor. Subsequent multimodality pancreatic imaging remained negative, requiring more invasive investigations. The tumor was localized by specialized arteriography using calcium stimulation to support the diagnosis of an insulinoma. However, repeated negative imaging led to further delays in definitive management, with worsening hypoglycemia. The surgery was finally performed three years after the initial presentation with successful removal of the tumor using intra-operative ultrasound.

Clinical discussion

It is important to emphasize that preoperative radiological imaging is useful to localize pancreatic lesions. However, most insulinomas could only be detected intraoperatively. The absence of suggestive radiological evidence should not deter surgeons from proceeding with definitive surgical intervention.

Conclusion

The case highlights the importance of a multidisciplinary approach in the management of a complicated case.

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Insulinoma is a difficult disease to diagnose due to its ambiguous location and insidious course.

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Insulinoma and type 2 diabetes mellitus coexistence is rare.

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Radiological imaging has improved in aiding the detection of pancreatic lesion but falsely negative results remain high.

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Surgical intervention is imperative for explorative diagnosis as well as treatment.

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A multidisciplinary approach could have been more successful in early detection and thus providing definitive treatment.

Successful surgical treatment of a patient with primary insulinoma of the liver

Insulinoma is the most frequent functional neuroendocrine tumor of the pancreas, which causes organic hyperinsulinism with severe hypoglycemia. There are no cases of primary insulinoma of the liver described. A 63-year-old female was admitted to our center presenting symptoms of severe hypoglycemia due to confirmed endogenic hyperinsulinism. None of the performed diagnostic procedures could reveal a pancreatic tumor. However, a pathologic mass in the sixth segment of the liver was detected. We performed arterial calcium stimulation that showed increased levels of insulin and c-peptide in almost all stimulated arteries. The highest and most prolonged peaks were detected at the points of the common hepatic artery and the right hepatic artery. After the surgical removal of the liver tumor, the blood glucose level was stabilized within the normal range. Post-operative pathomorphological investigation confirmed the diagnosis of a neuroendocrine tumor. The long-term survival results show correct treatment tactics without any signs of disease recurrence.

Ectopic insulinoma: case report

BACKGROUND

Ectopic insulinoma is a rare entity that is difficult to diagnose before surgery. This article reports two cases of ectopic insulinoma.

CASE PRESENTATION

Two patients manifested recurrent hypoglycemia with a typical Whipple triad. In terms of the qualitative diagnosis, the oral glucose tolerance test (OGTT) suggested a diagnosis of hyperinsulinemic hypoglycemia. However, preoperative imaging did not show a significant mass in the pancreas. In one patient, preoperative abdominal enhanced volume perfusion computed tomography (CT), somatostatin receptor imaging and ^99mTc-HYNIC-TOC SPECT/CT revealed a mass with a rich blood supply anterior to the duodenum. In the other patient, preoperative enhanced CT, magnetic resonance imaging (MRI) and ⁶⁸Ga-Exendin-4 PET/CT showed a mass above the spleen. After surgical removal of the tumor, both patients received a confirmed diagnosis of neuroendocrine tumors by postoperative pathology. The symptoms of hypoglycemia were relieved after surgery, and the blood glucose level was significantly increased.

CONCLUSION

Ectopic insulinoma is difficult to locate before surgery. ⁶⁸Ga-Exendin-4 PET/CT has a high diagnostic value. Surgical removal of the lesion is main treatment.