The Two-Year Paradox: A “Pancreatic Adenocarcinoma” Revealed as Metastatic Insulinoma
https://doi.org/10.15605/jafes.041.S1
- Author:
Lim Chee Jack
1
;
Gaayathri Krishnan
2
;
Ilham Ismail
3
;
Mahrunissa Mahadi
3
;
Nurul Atiqah Abu Sahmah
4
;
Tan Geok Chin
4
;
Norlaila Mustafa
5
;
Norasyikin A. Wahab
5
Author Information
1. Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia;Department of Medicine, Hospital Canselor Tuanku Muhriz;Ministry of Health Malaysia
2. Department of Medicine, Hospital Canselor Tuanku Muhriz;Ministry of Health Malaysia
3. Department of Medicine, Hospital Canselor Tuanku Muhriz
4. Department of Pathology, Hospital Tuanku Canselor Muhriz
5. Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia;Department of Medicine, Hospital Canselor Tuanku Muhriz
- Publication Type:Journal Article
- MeSH:
Adenocarcinoma;
Insulinoma;
Pancreatic Neoplasms
- From:
Journal of the ASEAN Federation of Endocrine Societies
2026;41(S1):89-
- CountryPhilippines
- Language:English
-
Abstract:
Introduction:Pancreatic neuroendocrine tumors (PNETs) are rare,
comprising less than 3% of all pancreatic neoplasms.
These tumors are broadly classified as functioning or nonfunctioning. Insulinoma is the most common functioning
PNET. Non-functioning PNETs often present significant diagnostic issues and may be misdiagnosed as pancreatic
adenocarcinoma, especially when immunohistochemical
evaluation is omitted during histological examination. We
describe a case of metastatic insulinoma that was misdiagnosed as a poorly differentiated pancreatic adenocarcinoma.
Case:A 65-year-old female first presented to a private hospital
in 2023 with obstructive jaundice and was found to
have a pancreatic head lesion that was causing biliary
obstruction. As a result, a biliary stent was placed. She
underwent aortocaval lymph node biopsy, and the result
showed poorly differentiated pancreatic adenocarcinoma.
Nonetheless, she refused surgical and oncological
intervention. Even so, she remained clinically stable and
maintained good functional status for 2 years.
In 2025, she presented to Hospital Canselor Tuanku
Muhriz with recurrent hypoglycemia fulfilling Whipple’s
triad. The unexpectedly indolent clinical course prompted
reassessment of the initial diagnosis. Biochemical evaluation
confirmed endogenous hyperinsulinemic hypoglycemia,
with inappropriately elevated insulin (11.03 µIU/mL) and
C-peptide levels (1,089 pmol/L). Computer tomography
of the abdomen revealed multiple hepatic lesions and
progressive lymphadenopathy, suggestive of metastatic
disease. Re-evaluation of the initial histopathological
specimen showed a well-differentiated neuroendocrine
tumor (Grade 1, Ki-67 ~2%). Hence, the diagnosis was
revised to metastatic insulinoma.
She was referred to the hepatobiliary surgical team for
surgical debulking, but the procedure was deemed highrisk and likely to have high mortality due to the extent of
the disease. She was managed with diazoxide and longacting somatostatin analogues for glycemic control.
Conclusion:This case highlights the critical importance of diagnostic
vigilance when evaluating pancreatic neoplasms. Persistent
or unexplained clinical courses, especially when endocrine
symptoms arise, should prompt thorough reassessment.
Immunohistochemical confirmation is essential to avoid
misdiagnosis and ensure optimal patient management.
- Full text:2026080414464689991EP_A126.pdf
