Laparoscope resection of retroperitoneal ectopic insulinoma: A rare case

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.

Insulinoma after sleeve gastrectomy: A case report

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) has been proposed as an effective and durable treatment for severe obesity and glucose metabolism disorders, and its prevalence has increased from 5% to 37% since 2008. One common complication after bariatric surgery is a postprandial hyperinsulinemic hypoglycemic state. While rare, insulinomas can cause this state, where symptoms are more common in the fasting state; thus, evaluation of insulin secretion is needed. Until now, there have been no reports of insulinoma after LSG.

CASE SUMMARY

We describe the case of a 43-year-old woman who was referred to the obesity clinic 2 years after LSG was performed. She had symptoms of hypoglycemia predominantly in the fasting state and documented hypoglycemia of less than 30 mg/dL, which are compatible with Whipple’s triad. Initially, dumping syndrome was suspected, but after a second low fasting plasma glucose was documented, a 72-h fasting test was performed that tested positive. Computed tomography and endoscopic ultrasound were performed, identifying the presence of a homogeneous hypoechoic semioval tumoral lesion in the pancreas. The diagnosis was compatible with insulinoma. After laparoscopic enucleation of the insulinoma, the symptoms and hypoglycemia disappeared. The histopathological report described a well-differentiated grade 2 neuroendocrine tumor with positive chromogranin and synaptophysin and Ki67 immunopositivity in 4% of the neoplastic cells.

CONCLUSION

Insulinoma after LSG is a rare condition, and clinicians must be aware of it, especially if the patient has hypoglycemic symptoms during the fasting state.

Ectopic insulinoma diagnosed by 68Ga-Exendin-4 PET/CT: A case report and review of literature

RATIONALE

Ectopic insulinomas are extremely rare and challenging to diagnose for clinicians. Precise preoperative localization is essential to successful treatment.

PATIENT CONCERNS

A 23-year-old man presented with a 1-year history of recurrent hypoglycemia.

DIAGNOSIS

Examinations in the local hospital did not reveal any pancreatic lesion. After admission, a fasting test and a 5-hour oral glucose tolerance test (OGTT) suggested a diagnosis of endogenous hyperinsulinemic hypoglycemia. Enhanced volume perfusion computed tomography (VPCT) revealed 2 nodules in the tail of the pancreas, a nodule in the gastric antrum, and a nodule in the hilum of the spleen. To differentiate which nodule was responsible for hypoglycemia, we performed 68Ga-Exendin-4 PET/CT and 68Ga-DOTATATE PET/CT which helped to make a conclusive diagnosis that the lesion in the gastric antrum was an ectopic insulinoma.

INTERVENTIONS

The patient was cured with minimally invasive laparoscopic resection of the tumor.

OUTCOMES

The symptoms were relieved and the blood glucose level remained normal after surgery.

CONCLUSIONS

This case shows that 68Gallium-exendin-4 PET/CT is useful for precise localization and thereby successful treatment of insulinoma, especially for occult insulinomas and those derived from an ectopic pancreas.

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.