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Updated: Mar 10, 2026
Robotic Enucleation of an Intra-Pancreatic Insulinoma in the Pancreatic Head
Published on: January 3, 2020
A Clinicopathological Study of Malignant Insulinoma in a Contemporary Series
Run Yu1, Nicholas N Nissen, Andrew Hendifar
1From the *Division of Endocrinology, Cedars-Sinai Medical Center; †Division of Endocrinology, UCLA David Geffen School of Medicine, ‡Department of Surgery, §Division of Hematology and Oncology, Cedars-Sinai Medical Center, Los Angeles, CA; ∥Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY; ¶Department of Gastroenterology, Peking Union Medical College Hospital, Beijing, China; and #Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA.
Objective:
The aim of the study was to address the origin and natural history of malignant insulinoma.
Methods:
Retrospective review of medical records of patients diagnosed with insulinoma at Cedars-Sinai Medical Center between 2000 and 2015 was conducted. Hormonal expression in tumor specimens was examined by immunostaining.
Results:
All the 9 patients with malignant insulinoma (35% of 26 patients with insulinoma) already had liver metastasis at hypoglycemia presentation with bulky cumulative tumor burden. Six patients had de novo diagnosis, 2 had known metastatic nonfunctioning pancreatic neuroendocrine tumor, and 1 had a known pancreatic mass. Tumor grade at presentation was G1 in 4 patients, G2 in 4, and unknown in 1. Four patients died 2 to 32 months after presentation, all with extensive liver tumor involvement. Tumor expression of proinsulin and insulin was heterogeneous and overall infrequent. The proinsulin levels and proinsulin/insulin molar ratio in patients with malignant versus benign insulinoma were 334 versus 44 pmol/L and 2.1 versus 0.9, respectively.
Conclusions:
Malignant insulinoma seems to arise from and behave like nonfunctioning pancreatic neuroendocrine tumor oncologically but with metachronous hyperinsulinemic hypoglycemia. High proinsulin levels and proinsulin/insulin molar ratio may suggest malignant insulinoma.
