Hydatid disease

Part 1: Basic-Level MCQs

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MCQ 1

Question

What is the generally reported overall postoperative mortality range following surgical treatment of hydatid disease of the liver?

Answer Choices

A. 0–1%

B. 0–3.2%

C. 5–10%

D. 15–20%

Correct Answer: B. 0–3.2%

Explanation

• Why the correct answer is correct: According to the excerpt, most studies report a postoperative mortality range between 0% and 3.2% for patients undergoing surgical treatment for hydatid disease of the liver.
• Why the other choices are incorrect:
  • A. 0–1%: While 0% is within the range, 1% as the upper limit is too low compared to the published data (up to 3.2%).
  • C. 5–10%: This is higher than the typically reported range, indicating it is not the usual finding.
  • D. 15–20%: This mortality rate is significantly higher than the data cited in the excerpt, making it incorrect.

Key Takeaways (4–5 sentences)

Postoperative mortality in hydatid liver surgery remains relatively low, often below 4%. This favorable range can be attributed to improvements in surgical techniques and postoperative care. Complications can still occur, especially when the cysts are large or complicated, but timely intervention reduces mortality risk. Knowledge of these statistics helps clinicians inform patients and optimize treatment plans.

Reference: Blumgart’s Surgery of the Liver, Biliary Tract and Pancreas, 8th edition, Chapter 72: “Hydatid Disease of the Liver” (p. 993)

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MCQ 2

Question

Which of the following factors is most commonly associated with an increased risk of postoperative complications after hydatid cyst surgery?

Answer Choices

A. Cyst size less than 5 cm

B. First-time surgery for a small solitary cyst

C. Centrohepatic cyst location

D. Absence of cystobiliary communications

Correct Answer: C. Centrohepatic cyst location

Explanation

• Why the correct answer is correct: The excerpt mentions that centrohepatic cyst location is one of the significant predictive factors for morbidity. Complex anatomical positioning can increase the chance of surgical complications, such as biliary fistulas or vascular issues.
• Why the other choices are incorrect:
  • A. Cyst size less than 5 cm: The excerpt specifically indicates larger cysts (over 10 cm) are associated with more complications.
  • B. First-time surgery for a small solitary cyst: Such patients generally have a lower risk because the disease extent is limited, and there is no additional complexity from previous surgeries.
  • D. Absence of cystobiliary communications: Having a cystobiliary communication is a known risk factor for complications; if communications are absent, the risk is generally lower.

Key Takeaways (4–5 sentences)

Major factors influencing postoperative complications include advanced age, large cyst size (>10 cm), previous surgeries, and challenging cyst locations such as centrohepatic lesions. Identifying these risk factors aids in preoperative planning and counseling. Surgeons may choose specific techniques (conservative vs. radical) based on cyst location and complexity. Proactive management of any cystobiliary communication is crucial for reducing morbidity.

Reference: Blumgart’s Surgery of the Liver, Biliary Tract and Pancreas, 8th edition, Chapter 72: “Hydatid Disease of the Liver” (p. 993)

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MCQ 3 (All are true EXCEPT…)

Question

Regarding the recurrence of hydatid cysts after surgical treatment, all of the following statements are true EXCEPT:

Answer Choices

A. Recurrence can occur years after the initial surgery, even up to 20 years later.

B. Recurrence can be identified by newly appearing cysts in previously untreated liver segments.

C. Ultrasound surveillance is typically recommended every week for the first year postoperatively.

D. Surgical technique and surgeon experience can influence the recurrence rate.

Correct Answer: C. Ultrasound surveillance is typically recommended every week for the first year postoperatively.

Explanation

• Why the correct answer is correct (i.e., the false statement): The excerpt recommends ultrasound monitoring at 1 month after discharge, then every 6 months for 4 years, and annually thereafter. Performing weekly ultrasounds in the first year is not a standard recommendation and is considered excessive.
• Why the other choices are incorrect (i.e., they are true):
  • A. Late recurrences (up to 20 years later) are well-documented.
  • B. New cyst development in untreated liver segments or peritoneal regions is part of the recurrence definition.
  • D. Skilled surgeons using appropriate techniques reduce the likelihood of recurrence due to meticulous removal and minimal spillage.

Key Takeaways (4–5 sentences)

Recurrence in hydatid disease can manifest long after the initial surgery, underscoring the importance of long-term imaging follow-up. Postoperative imaging protocols help detect any new cysts early. Surgeon skill and careful surgical techniques (particularly with radical approaches) lower the recurrence rates. Appropriate follow-up intervals—every 6 months initially, then annually—are standard in clinical practice.

Reference: Blumgart’s Surgery of the Liver, Biliary Tract and Pancreas, 8th edition, Chapter 72: “Hydatid Disease of the Liver” (p. 993)

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MCQ 4

Question

Which statement best describes the definition of recurrence in hydatid liver disease post-surgery?

Answer Choices

A. The persistence of the original cyst without any new disease foci

B. The reappearance of symptomatic biliary fistula with no imaging changes

C. The development of new and growing cysts either at the original site or a distant site

D. The improvement of hydatid serology without imaging confirmation

Correct Answer: C. The development of new and growing cysts either at the original site or a distant site

Explanation

• Why the correct answer is correct: According to the excerpt, recurrence is defined as the appearance of new and growing cysts after therapy, including local recurrence at the same site or distant recurrence in other segments/peritoneal cavity.
• Why the other choices are incorrect:
  • A. Persistence of the original cyst indicates lack of complete treatment response rather than a new recurrence.
  • B. Reappearance of a biliary fistula alone does not define cystic recurrence; it’s a complication but not necessarily a cystic relapse.
  • D. Serology may improve or worsen for various reasons and should be correlated with imaging—imaging is pivotal in diagnosing true recurrence.

Key Takeaways (4–5 sentences)

Recurrence in hydatid disease involves new cyst formation at the same or different anatomical sites. Spillage of cyst contents during surgery and incomplete removal of parasite elements are common causes. Periodic imaging after surgery is critical in detecting such events. Timely recognition allows for earlier re-intervention and better outcomes.

Reference: Blumgart’s Surgery of the Liver, Biliary Tract and Pancreas, 8th edition, Chapter 72: “Hydatid Disease of the Liver” (p. 993)

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MCQ 5

Question

A 45-year-old patient with a known 12 cm hydatid cyst in the right lobe of the liver undergoes surgery. Based on the excerpt, which of the following outcomes is most likely?

Answer Choices

A. Zero chance of developing postoperative complications due to advanced surgical techniques

B. Higher likelihood of postoperative complications because the cyst is larger than 10 cm

C. Immediate postoperative mortality exceeding 20% due to the cyst size

D. No need for follow-up imaging if the surgery was radical and apparently successful

Correct Answer: B. Higher likelihood of postoperative complications because the cyst is larger than 10 cm

Explanation

• Why the correct answer is correct: The excerpt highlights that cysts greater than 10 cm are a notable risk factor for increased postoperative morbidity. This size correlates with technical challenges and potential complications such as biliary fistula and hemorrhage.
• Why the other choices are incorrect:
  • A. No surgical intervention is without complications; large cysts increase risk despite modern techniques.
  • C. Mortality above 20% is not supported by the excerpt’s data; reported mortality rarely exceeds 3.2%.
  • D. Follow-up imaging is necessary in all cases to detect potential recurrences or complications, regardless of the procedure’s apparent success.

Key Takeaways (4–5 sentences)

Large hydatid cysts (>10 cm) pose significant surgical challenges and elevate the risk of complications, underscoring the importance of careful perioperative management. Despite advanced surgical approaches, patients require close monitoring. Surgeons and physicians should maintain a vigilant follow-up schedule to ensure early detection of recurrence or late complications. Patient education about the importance of follow-up imaging is essential for optimal outcomes.

Reference: Blumgart’s Surgery of the Liver, Biliary Tract and Pancreas, 8th edition, Chapter 72: “Hydatid Disease of the Liver” (p. 993)

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Please review these Basic-Level MCQs and let me know your thoughts. Once confirmed, I will provide Part 2: Advanced-Level MCQs followed by the Key Takeaways for the entire topic.

MCQ 6

Question

Which molecular pathway alteration is least likely to contribute to imatinib resistance in gastrointestinal stromal tumors (GISTs)?

Answer Choices

A. Secondary KIT mutations in exon 13

B. Activation of the PI3K/AKT pathway

C. Overexpression of PDGFRA

D. Loss of PTEN function

Correct Answer

C. Overexpression of PDGFRA

Explanation

1. Why the correct answer is correct: Overexpression of PDGFRA is not typically associated with imatinib resistance. Instead, mutations in PDGFRA, especially the D842V mutation, are linked to primary resistance, but overexpression alone does not confer resistance.
2. Why the other choices are incorrect:
   • A. Secondary KIT mutations in exon 13: These mutations can alter the binding site of imatinib, leading to resistance.
   • B. Activation of the PI3K/AKT pathway: This downstream signaling pathway can promote survival and proliferation despite imatinib treatment.
   • D. Loss of PTEN function: PTEN loss can activate the PI3K/AKT pathway, contributing to resistance mechanisms.

Key Takeaways for the Topic involved in that mcq

• Imatinib resistance in GISTs can arise from various molecular alterations.
• Secondary KIT mutations, particularly in exon 13, are a common mechanism of acquired resistance.
• Activation of alternative signaling pathways like PI3K/AKT plays a crucial role in sustaining tumor growth despite therapy.
• Loss of tumor suppressor genes such as PTEN can facilitate resistance by activating survival pathways.
• Understanding the molecular basis of resistance informs the development of second-line therapies and combination treatments.

Reference

Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)

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MCQ 7

Question

All of the following are emerging therapeutic targets in the treatment of gastrointestinal stromal tumors (GISTs) except:

Answer Choices

A. Avapritinib

B. Ripretinib

C. Erlotinib

D. Dasatinib

Correct Answer

C. Erlotinib

Explanation

1. Why the correct answer is correct: Erlotinib is an EGFR inhibitor primarily used in non-small cell lung cancer and pancreatic cancer, not commonly targeted in GIST therapy.
2. Why the other choices are incorrect:
   • A. Avapritinib: Targets PDGFRA D842V mutations, addressing specific resistant GISTs.
   • B. Ripretinib: Acts as a switch-control kinase inhibitor, effective in advanced GISTs resistant to other treatments.
   • D. Dasatinib: A multi-kinase inhibitor being explored for its efficacy in GISTs with certain resistance profiles.

Key Takeaways for the Topic involved in that mcq

• Emerging therapies are expanding the arsenal against resistant GISTs.
• Avapritinib specifically targets the PDGFRA D842V mutation, offering options for previously untreatable cases.
• Ripretinib provides a novel mechanism by inhibiting multiple kinases implicated in GIST proliferation.
• Dasatinib's role as a multi-kinase inhibitor may offer benefits in complex resistance scenarios.
• Erlotinib’s primary indications do not include GISTs, highlighting the specificity required in targeted therapies.

Reference

Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)

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MCQ 8

Question

In a comparative study of KIT versus PDGFRA mutant gastrointestinal stromal tumors (GISTs), which of the following statements is incorrect?

Answer Choices

A. KIT-mutant GISTs are more responsive to imatinib than PDGFRA-mutant GISTs.

B. PDGFRA-mutant GISTs typically present with larger tumor sizes at diagnosis compared to KIT-mutant GISTs.

C. KIT-mutant GISTs are more commonly located in the stomach than PDGFRA-mutant GISTs.

D. PDGFRA-mutant GISTs have a higher frequency of malignant behavior compared to KIT-mutant GISTs.

Correct Answer

D. PDGFRA-mutant GISTs have a higher frequency of malignant behavior compared to KIT-mutant GISTs.

Explanation

1. Why the correct answer is correct: PDGFRA-mutant GISTs generally have a similar or slightly better prognosis compared to KIT-mutant GISTs, and do not inherently possess a higher frequency of malignant behavior.
2. Why the other choices are incorrect:
   • A. KIT-mutant GISTs are more responsive to imatinib than PDGFRA-mutant GISTs: KIT mutations are typically more sensitive to imatinib.
   • B. PDGFRA-mutant GISTs typically present with larger tumor sizes at diagnosis compared to KIT-mutant GISTs: PDGFRA mutations are often associated with certain anatomical and size characteristics.
   • C. KIT-mutant GISTs are more commonly located in the stomach than PDGFRA-mutant GISTs: KIT mutations are prevalent in gastric locations.

Key Takeaways for the Topic involved in that mcq

• KIT and PDGFRA mutations define distinct molecular subtypes of GISTs with differing clinical behaviors.
• KIT-mutant GISTs generally exhibit greater sensitivity to imatinib, influencing treatment decisions.
• Anatomical location and tumor size can vary based on the underlying genetic mutations, aiding in prognosis and management.
• Understanding the comparative behaviors of different mutant GISTs is essential for personalized therapy.
• Molecular profiling remains a cornerstone in the strategic management of GISTs to optimize outcomes.

Reference

Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)

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MCQ 9

Question

A researcher is designing a study to evaluate the efficacy of a novel tyrosine kinase inhibitor in GISTs with wild-type KIT and PDGFRA genes. Which of the following mechanisms should the researcher primarily investigate to assess potential therapeutic targets?

Answer Choices

A. BRAF mutations

B. SDH (succinate dehydrogenase) deficiency

C. EGFR overexpression

D. HER2 amplification

Correct Answer

B. SDH (succinate dehydrogenase) deficiency

Explanation

1. Why the correct answer is correct: SDH-deficient GISTs represent a subset of wild-type KIT and PDGFRA tumors, often associated with Carney-Stratakis syndrome and representing a distinct molecular pathway.
2. Why the other choices are incorrect:
   • A. BRAF mutations: Less common in GISTs and not the primary pathway in wild-type cases.
   • C. EGFR overexpression: Not a primary driver in GIST pathogenesis.
   • D. HER2 amplification: More relevant in other cancers like breast and gastric, not predominant in GISTs.

Key Takeaways for the Topic involved in that mcq

• Wild-type GISTs, lacking KIT and PDGFRA mutations, require alternative therapeutic targets.
• SDH deficiency is a critical area of interest for developing treatments in wild-type GISTs.
• Understanding alternative genetic and molecular pathways is essential for addressing resistance and improving outcomes.
• BRAF, EGFR, and HER2, while relevant in other cancers, are not primary targets in wild-type GISTs.
• Continued research into the diverse molecular landscape of GISTs facilitates the advancement of personalized medicine.

Reference

Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)

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MCQ 10

Question

All of the following factors are considered when stratifying the risk of recurrence in gastrointestinal stromal tumors (GISTs) except:

Answer Choices

A. Tumor size

B. Mitotic index

C. Patient’s age

D. Tumor location

Correct Answer

C. Patient’s age

Explanation

1. Why the correct answer is correct: Patient’s age is not a primary factor in GIST risk stratification. The main factors include tumor size, mitotic rate, and location.
2. Why the other choices are incorrect:
   • A. Tumor size: A crucial determinant, with larger tumors having higher recurrence risk.
   • B. Mitotic index: High mitotic rates are associated with increased malignancy and recurrence.
   • D. Tumor location: Certain locations, like the small intestine, are linked to a higher risk compared to gastric locations.

Key Takeaways for the Topic involved in that mcq

• Risk stratification in GISTs primarily relies on tumor-specific factors rather than patient demographics.
• Tumor size and mitotic index are paramount in determining the likelihood of recurrence.
• Anatomical location influences the prognosis, with gastric GISTs generally having a better outcome.
• Accurate risk assessment guides decisions regarding adjuvant therapy and follow-up strategies.
• Understanding these factors is essential for tailoring patient management and improving survival rates.

Reference

Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)

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Key Takeaways for the Topic involved in all MCQs

• Molecular Characteristics: GISTs are primarily driven by mutations in KIT and PDGFRA genes, which are critical for diagnosis and targeted therapy. Wild-type GISTs, lacking these mutations, require alternative therapeutic approaches such as targeting SDH deficiencies.
• Diagnostic Markers: CD117 (c-KIT) is a pivotal immunohistochemical marker for GISTs, with high sensitivity aiding in accurate diagnosis. Other markers like DOG1 can also support diagnostic processes.
• Risk Stratification: Tumor size, mitotic rate, and location are essential for assessing the risk of recurrence. High-risk features necessitate adjuvant therapies to mitigate recurrence risks.
• Therapeutic Strategies: Imatinib remains the first-line treatment for metastatic GISTs with KIT or PDGFRA mutations. Resistance mechanisms, including secondary mutations and alternative pathway activations, are significant challenges that necessitate second and third-line therapies like sunitinib and regorafenib.
• Emerging Treatments: Newer agents such as avapritinib and ripretinib are expanding treatment options, particularly for resistant or specific mutation subtypes, enhancing personalized medicine approaches.
• Prognostic Factors: Understanding the prognostic implications of different mutations and tumor behaviors is crucial for tailoring patient management and improving survival outcomes.
• Clinical Management: Comprehensive molecular profiling is indispensable for guiding treatment decisions, especially in cases of resistance or wild-type GISTs, ensuring optimal therapeutic interventions.
• Resistance Mechanisms: Exploring and addressing the molecular basis of drug resistance in GISTs are vital for developing effective long-term treatment strategies and improving patient prognosis.

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Reference for All MCQs Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)

MCQ 11

Question

Based on the Joensuu criteria for risk stratification of gastrointestinal stromal tumors (GISTs), which of the following tumors is classified as high risk?

Answer Choices

A. Gastric GIST, 5.5 cm, 4 mitoses per 50 high-power fields (HPF)

B. Small Intestinal GIST, 5 cm, 6 mitoses per 50 HPF

C. Rectal GIST, 4.8 cm, 5 mitoses per 50 HPF

D. Gastric GIST, 5 cm, 5 mitoses per 50 HPF

Correct Answer

B. Small Intestinal GIST, 5 cm, 6 mitoses per 50 high-power fields (HPF)

Explanation

1. Why the correct answer is correct:

   According to the Joensuu criteria, high-risk GISTs are typically characterized by larger tumor size and higher mitotic rates. Specifically, for small intestinal GISTs, a tumor size greater than 5 cm combined with a mitotic rate exceeding 5 mitoses per 50 HPF categorizes the tumor as high risk.

2. Why the other choices are incorrect:

   • A. Gastric GIST, 5.5 cm, 4 mitoses per 50 HPF: While the size exceeds 5 cm, the mitotic rate is below the high-risk threshold. For gastric GISTs, a mitotic rate >5 per 50 HPF is required for high-risk classification.
   • C. Rectal GIST, 4.8 cm, 5 mitoses per 50 HPF: The tumor size is slightly below 5 cm, and although the mitotic rate meets the threshold, the combination does not sufficiently meet the high-risk criteria.
   • D. Gastric GIST, 5 cm, 5 mitoses per 50 HPF: Both size and mitotic rate are at the threshold, which typically categorizes the tumor as intermediate risk rather than high risk.

Key Takeaways for the Topic Involved in this MCQ

• Epidemiology:
  • GISTs are the most common mesenchymal tumors of the gastrointestinal tract, predominantly occurring in adults with a median age of around 60 years.
  • They are slightly more common in males compared to females.
• Molecular Biology:
  • The majority of GISTs harbor mutations in the KIT gene (~75-80%) or the PDGFRA gene (~5-10%).
  • Wild-type GISTs lack these mutations and may involve other genetic alterations such as SDH (succinate dehydrogenase) deficiency.
• Diagnosis:
  • Imaging: CT scans and MRI are essential for tumor localization, sizing, and assessing metastasis.
  • Histology and Immunohistochemistry: CD117 (c-KIT) positivity is a hallmark for diagnosis. DOG1 is another sensitive marker.
  • Genetic Testing: Molecular profiling is crucial for identifying specific mutations to guide targeted therapy.
• Risk Stratification (Joensuu Criteria):
  • Key Factors: Tumor size, mitotic rate, and location.
  • High-Risk Features:
    • Tumor size >5 cm.
    • Mitotic rate >5 per 50 HPF.
    • Non-gastric location (e.g., small intestine, rectum).
  • Intermediate Risk: Combines factors that do not meet the high-risk thresholds but still indicate significant risk of recurrence.
• Treatment:
  • Surgical Resection: The primary treatment for localized GISTs aiming for complete, margin-negative resection.
  • Targeted Therapy:
    • Imatinib: First-line treatment for metastatic or high-risk GISTs with KIT or PDGFRA mutations.
    • Sunitinib and Regorafenib: Used as second and third-line treatments respectively after imatinib resistance.
    • Avapritinib and Ripretinib: Emerging therapies targeting specific resistant mutations.
  • Adjuvant Therapy: Recommended for high-risk GISTs post-surgery to reduce recurrence risk.
• Prognosis:
  • Dependent on factors such as tumor size, mitotic rate, and location.
  • Gastric GISTs generally have a better prognosis compared to those located in the small intestine or rectum.
  • High-risk tumors have a higher likelihood of recurrence and metastasis, necessitating aggressive treatment and close follow-up.
• Resistance Mechanisms:
  • Secondary Mutations: Especially in the KIT gene, leading to imatinib resistance.
  • Alternative Pathway Activation: Such as the PI3K/AKT pathway, contributing to continued tumor growth despite therapy.
  • Addressing resistance involves using second-line therapies and exploring combination treatments.
• Clinical Management:
  • Comprehensive evaluation including performance status, presence of symptoms, and molecular profiling.
  • Multidisciplinary approach involving surgeons, oncologists, and radiologists for optimal management.
  • Regular follow-up with imaging to monitor for recurrence or metastasis.
• Emerging Research:
  • Ongoing studies focus on novel targeted therapies and immunotherapies to improve outcomes for resistant or wild-type GISTs.
  • Investigations into the molecular pathways involved in GIST pathogenesis aim to identify new therapeutic targets.

Reference

Shackleford’s Surgery of the Alimentary Tract, 8th edition, Chapter 81: "Gastrointestinal Stromal Tumors" (pp. 951–958)