0
Special Feature |

Image of the Month—Quiz Case FREE

D. Dean Potter, MD; Patrick D. Munson, MD; Clive S. Grant, MD
[+] Author Affiliations

Author Affiliations: Department of Surgery, Mayo Clinic and Mayo College of Medicine, Rochester, Minn.


Arch Surg. 2005;140(6):611. doi:10.1001/archsurg.140.6.611.
Text Size: A A A
Published online

A 45-year-old woman presented with a 3-year history of confusion and seizures refractory to anticonvulsant therapy. A biochemical diagnosis of excess endogenous insulin production was established by a serum glucose level of 46 mg/dL, serum insulin level of 4 μIU/mL, C-peptide level of 0.9 ng/mL, proinsulin level of 19.9 pmol/L, and a negative sulfonylurea screen. Her neuroglycopenic symptoms were relieved by intravenous glucose administration. She had no history of peptic ulcer disease (serum gastrin level of <25 pg/mL), nipple discharge, or hypercalcemia (serum calcium level of 9.6 mg/dL). By preoperative transabdominal ultrasound, a 1-cm hypervascular mass was identified in the body of the posterior pancreas (Figure 1). She was taken to the operating room for enucleation of a well-circumscribed 7-mm insulinoma that was confirmed by immunohistochemical staining. No additional masses were identified intraoperatively by palpation. Her intraoperative serum glucose levels rebounded to 99 mg/dL without glucose infusion.

Place holder to copy figure label and caption
Figure 1.

Transabdominal ultrasound demonstrating a 1-cm mass in the body of the posterior pancreas consistent with an islet cell tumor.

Graphic Jump Location

Her postoperative course was complicated by recurrent neuroglycopenic symptoms on the second postoperative day while ambulating. Repeated fasting laboratory values demonstrated a serum glucose level of 44 mg/dL, serum insulin level of 6.6 μIU/mL, C-peptide level of 0.7 ng/mL, and a negative sulfonylurea screen. Her neuroglycopenic symptoms were again relieved by intravenous glucose administration.

WHAT IS THE DIAGNOSIS?

A. Surreptitious insulin administration

B. Incomplete enucleation of the previous insulinoma

C. A second insulinoma

D. Noninsulinoma pancreatogenous hypoglycemic syndrome (β-cell hyperplasia or nesidioblastosis)

Figures

Place holder to copy figure label and caption
Figure 1.

Transabdominal ultrasound demonstrating a 1-cm mass in the body of the posterior pancreas consistent with an islet cell tumor.

Graphic Jump Location

Tables

References

Correspondence

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Submit a Comment

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Topics
PubMed Articles
JAMAevidence.com

The Rational Clinical Examination
Evidence Summary and Review 2

The Rational Clinical Examination
Location of Paracentesis and Ultrasound Guidance