Part 1: 5 Basic-Level MCQs

MCQ 1

Question

Which of the following statements about the epidemiology of pancreatic neuroendocrine tumors (PNETs) is correct?

Answer Choices

A. PNETs are the most common type of pancreatic tumors.

B. The incidence of PNETs has been decreasing over the past 30 years.

C. PNETs account for about 1–2% of all pancreatic tumors.

D. PNETs are found exclusively in older males.

Correct Answer: C. PNETs account for about 1–2% of all pancreatic tumors.

Explanation

Why C is correct: According to the excerpt, PNETs make up approximately 1–2% of all pancreatic tumors, highlighting their relative rarity among pancreatic neoplasms.
Why A is incorrect: PNETs are the second most common tumor of the pancreas, not the most common (the most common is pancreatic adenocarcinoma).
Why B is incorrect: The incidence of PNETs has actually risen over the past three decades rather than decreased.
Why D is incorrect: PNETs affect males and females equally, and although they are often diagnosed between ages 60–80, they are not found “exclusively” in males.

Key Takeaways (4–5 sentences)

PNETs are relatively rare but increasingly recognized neoplasms of the pancreas. They are well-differentiated neuroendocrine tumors that can be either functional (hormone-producing) or nonfunctional. Overall, PNETs comprise a small percentage of all pancreatic cancers, yet their incidence is rising. Their clinical behavior can range from indolent to aggressive, requiring individualized evaluation and management.

Reference

Blumgart's Surgery of the Liver, Biliary Tract and Pancreas, 7th edition,

Chapter 65: "Pancreatic neuroendocrine tumors: Classification, clinical picture, diagnosis, and therapy,"

Subtopic: "Epidemiology," pp. 903–912

MCQ 2 (All are true EXCEPT…)

Question

All of the following statements regarding functional pancreatic neuroendocrine tumors (PNETs) are true EXCEPT:

Answer Choices

A. Insulinomas can be diagnosed using a 72-hour fasting test with concurrent measurements of insulin, glucose, and C-peptide.

B. VIPomas classically present with profound watery diarrhea and hypokalemia.

C. Gastrinomas typically cause Zollinger-Ellison syndrome and are often found within the “gastrinoma triangle.”

D. Glucagonomas rarely cause any significant clinical symptoms and are usually benign.

Correct Answer: D. Glucagonomas rarely cause any significant clinical symptoms and are usually benign.

Explanation

Why D is incorrect (and thus the correct choice in an “EXCEPT” question): Glucagonomas do cause important clinical symptoms such as necrolytic migratory erythema, weight loss, and glucose intolerance. They are often malignant, and up to 60% have liver metastases at diagnosis.
Why A is correct: The 72-hour fasting test measuring insulin and proinsulin levels alongside hypoglycemia is standard in diagnosing insulinomas.
Why B is correct: VIPomas characteristically present with large-volume watery diarrhea, hypokalemia, and achlorhydria (often called “pancreatic cholera”).
Why C is correct: Gastrinomas are often located within the gastrinoma triangle (bounded by the cystic and common bile ducts superiorly, the junction of the second and third portions of the duodenum inferiorly, and the junction of the neck and body of the pancreas medially).

Key Takeaways (4–5 sentences)

Functional PNETs secrete excess hormones that lead to distinct clinical syndromes, often aiding in early diagnosis. Insulinomas present with hypoglycemia; gastrinomas with multiple peptic ulcers; VIPomas with watery diarrhea; and glucagonomas with necrolytic migratory erythema and hyperglycemia. Although insulinomas are often benign, other functional PNETs—like gastrinomas, VIPomas, and glucagonomas—have a substantial rate of malignancy. Early recognition of these hormone-related syndromes is crucial to guide imaging, confirm the diagnosis, and plan therapy.

Reference

Blumgart's Surgery of the Liver, Biliary Tract and Pancreas, 7th edition,

Chapter 65: "Pancreatic neuroendocrine tumors: Classification, clinical picture, diagnosis, and therapy,"

Subtopic: "Functional Tumors: Clinical Features," pp. 903–912

MCQ 3

Question

Which of the following is a recognized familial syndrome that predisposes to the development of pancreatic neuroendocrine tumors (PNETs)?

Answer Choices

A. Marfan syndrome

B. Multiple endocrine neoplasia type 1 (MEN1)

C. Lynch syndrome (HNPCC)

D. Peutz-Jeghers syndrome

Correct Answer: B. Multiple endocrine neoplasia type 1 (MEN1)

Explanation

Why B is correct: MEN1 is an autosomal dominant disorder characterized by parathyroid adenomas, pituitary adenomas, and pancreatic neuroendocrine tumors. Around 5–7% of PNETs occur in the context of MEN1.
Why A is incorrect: Marfan syndrome involves connective tissue abnormalities and is not typically associated with PNETs.
Why C is incorrect: Lynch syndrome predisposes to colorectal cancer and other malignancies, but PNETs are not a classic tumor in this syndrome.
Why D is incorrect: Peutz-Jeghers syndrome is associated with gastrointestinal polyps and certain cancers, but it is more famously linked with pancreatic adenocarcinoma risk rather than PNETs.

Key Takeaways (4–5 sentences)

Several familial syndromes increase the risk of PNETs, with MEN1 being the most common. Patients with MEN1 may harbor multiple pancreatic endocrine tumors and often present at a younger age. Other syndromes linked to PNETs include von Hippel-Lindau, tuberous sclerosis, and neurofibromatosis type I. Identifying familial cases is important, as genetic testing and screening of relatives can facilitate early detection and management.

Reference

Blumgart's Surgery of the Liver, Biliary Tract and Pancreas, 7th edition,

Chapter 65: "Pancreatic neuroendocrine tumors: Classification, clinical picture, diagnosis, and therapy,"

Subtopic: "Familial Syndromes," pp. 903–912

MCQ 4 (Scenario-Based)

Question

A 42-year-old patient presents with episodes of confusion, sweating, and palpitations that improve after eating. During a supervised 72-hour fast, her blood glucose level drops below 40 mg/dL, and her insulin and proinsulin levels remain inappropriately elevated. Imaging suggests a 1.2 cm lesion in the pancreatic tail. Which of the following best describes the most likely diagnosis?

Answer Choices

A. Nonfunctional PNET

B. VIPoma

C. Insulinoma

D. Gastrinoma

Correct Answer: C. Insulinoma

Explanation

Why C is correct: Clinical symptoms of hypoglycemia (confusion, sweating, palpitations) that resolve with feeding, plus elevated insulin/proinsulin during fasting, are hallmark features of an insulinoma. These tumors are often small (<2 cm) and typically located anywhere in the pancreas, commonly in the tail.
Why A is incorrect: A nonfunctional PNET does not typically produce hypoglycemic symptoms or any hormone-related syndrome.
Why B is incorrect: VIPomas cause profuse watery diarrhea, hypokalemia, and achlorhydria, not hypoglycemia.
Why D is incorrect: Gastrinomas would cause peptic ulcer disease (Zollinger-Ellison syndrome) due to high gastrin levels.

Key Takeaways (4–5 sentences)

Insulinomas are the most frequent functioning PNET and characteristically present with hypoglycemic symptoms, especially during fasting. The confirmatory test includes documenting inappropriately high levels of insulin/proinsulin alongside low blood glucose during a 72-hour fast. These tumors tend to be small and can be difficult to localize, sometimes requiring specialized imaging or intraoperative ultrasound. Surgical resection offers curative potential when the disease is localized and without metastases.

Reference

Blumgart's Surgery of the Liver, Biliary Tract and Pancreas, 7th edition,

Chapter 65: "Pancreatic neuroendocrine tumors: Classification, clinical picture, diagnosis, and therapy,"

Subtopic: "Functional Tumors: Insulinoma," pp. 903–912

MCQ 5 (Descriptive / Imaging Focus)

Question

Which imaging modality is considered particularly sensitive for detecting small pancreatic neuroendocrine tumors (PNETs), especially those under 2 cm in size?

Answer Choices

A. Standard abdominal ultrasound (transabdominal)

B. Magnetic resonance imaging (MRI) without contrast

C. Endoscopic ultrasound (EUS)

D. Plain X-ray of the abdomen

Correct Answer: C. Endoscopic ultrasound (EUS)

Explanation

Why C is correct: EUS is highly sensitive for detecting small pancreatic lesions, especially PNETs under 2 cm, and it also allows for fine needle biopsy. Sensitivities have been reported up to 80–90% or higher in skilled centers.
Why A is incorrect: Standard transabdominal ultrasound, although sometimes useful, is less sensitive for small PNETs.
Why B is incorrect: MRI is valuable (especially with contrast) but is generally considered secondary when very small lesions are suspected; EUS tends to identify smaller lesions more reliably.
Why D is incorrect: Plain X-ray of the abdomen has no significant role in detecting PNETs.

Key Takeaways (4–5 sentences)

Imaging is crucial for the diagnosis and management of PNETs. EUS stands out for localizing small, well-differentiated PNETs and for obtaining tissue diagnosis via fine needle aspiration. Cross-sectional imaging like contrast-enhanced CT or MRI is also essential for staging and detecting metastatic disease. Finally, functional imaging (e.g., Ga-68 DOTATATE PET/CT) helps identify somatostatin receptor expression, guiding potential treatment with somatostatin analogs or peptide receptor radionuclide therapy.

Reference

Blumgart's Surgery of the Liver, Biliary Tract and Pancreas, 7th edition,

Chapter 65: "Pancreatic neuroendocrine tumors: Classification, clinical picture, diagnosis, and therapy,"

Subtopic: "Imaging," pp. 903–912

(Please let me know if you would like to proceed with the Advanced-Level MCQs.)