Pancreatic insulinoma misdiagnosed as atrial fibrillation: A case report from Iraq

Abstract

Rationale: Pancreatic insulinomas are the most frequent pancreatic endocrine neoplasms. They are insulin-secreting pancreatic tumors that induce extreme, recurrent, and near-fatal hypoglycemia. Insulinomas affect 1 to 4 individuals in a million of the general population and account for about 1% to 2% of all pancreatic tumors.

Patient concerns: Recurrent episodes of sweating, tremor, weakness, confusion, palpitation, blurred vision, and fainting for 2 months and was misdiagnosed as having atrial fibrillation.

Diagnosis: He was misdiagnosed as having atrial fibrillation to highlight the importance of atrial fibrillation as unusual mimicker of insulinoma and to encourage clinicians about the importance of early and appropriate management in such cases.

Interventions: Endoscopic ultrasound for the pancreatic parenchyma was done, and it showed a hypoechoic homogenous mass located at the pancreatic head measuring 12 mm × 15 mm with no local vascular involvement, blue in elastography, hypervascular with Doppler study, and a normal pancreatic duct diameter.

Outcomes: His condition was stable, and he was discharged home 2 days later.

Conclusion: The diagnosis of insulinoma is usually difficult and late due to the extremely low incidence of the disease and the similarity of its clinical presentation to numerous other conditions, the most reported is epilepsy.

Figure 1.

MRI of the abdomen with IV contrast showing a well-defined soft tissue mass that was round in shape, homogenously avidly enhanced, and measured about 11 × 13 mm at the head of the pancreas. MRI = magnetic resonance imaging.

Figure 2.

(A, B, C) Intra-operative images showing the tumor at the head of the pancreas. (D) This image showing the tumor after resection.

Figure 3.

Histopathological slides demonstrating a diffuse infiltration of plasmacytoid epithelial cells under low power microscopy (A) and under high power microscopy (B).

Figure 4.

Immunohistochemistry with synaptophysin (A) and CD56 (B) showing diffusely strong positive results. (C) An immunohistochemistry with Ki67 and it showed a score of 3% of positively stained tumor cells.