A 72-year-old man presents to the colorectal clinic following a screening colonoscopy that identified a 35 mm sessile polyp in the sigmoid colon. The polyp was not removed during colonoscopy due to size and morphology. Subsequent histology from biopsies shows high-grade dysplasia. CT colonography confirms the polyp but no other lesions. What is the most appropriate management for this lesion?
Q122
A 35-year-old man presents with a 40-hour history of right iliac fossa pain, nausea, and fever. CT abdomen demonstrates an inflamed appendix with surrounding fat stranding. During laparoscopic appendicectomy, the appendix base is severely inflamed and friable. After dividing the mesoappendix, the surgeon is unable to securely ligate the appendix base with an endoloop due to tissue quality. What is the most appropriate next step in management?
Q123
A 68-year-old man with newly diagnosed sigmoid colon adenocarcinoma undergoes staging investigations. CT chest/abdomen/pelvis shows the primary tumour with invasion through the muscularis propria into the pericolonic fat, 4 enlarged regional lymph nodes, and 3 small (<1 cm) lesions in the right lobe of the liver consistent with metastases. Liver function tests are normal. Carcinoembryonic antigen (CEA) is 85 ng/mL. What is the most appropriate initial management strategy according to current UK colorectal cancer guidelines?
Q124
A 56-year-old woman presents to the emergency department with a 6-hour history of severe pain in her right groin. She has a known right femoral hernia which has always been reducible. On examination, there is a tense, tender mass below and lateral to the pubic tubercle. The overlying skin appears dusky. Heart rate is 105 bpm, temperature 37.9°C. What is the anatomical structure that forms the medial border of the femoral canal and is at risk during repair of this hernia?
Q125
A 43-year-old man presents to the emergency department with a 72-hour history of right lower quadrant pain, fever of 39.1°C, and rigors. CT abdomen and pelvis demonstrates a retrocaecal appendix with surrounding fat stranding and a 6 cm × 5 cm pericaecal collection with gas locules. Blood tests show WBC 16.8 × 10⁹/L, CRP 245 mg/L. The patient has been symptomatic for 4 days. What is the most appropriate initial management strategy?
Q126
A 65-year-old woman undergoes curative anterior resection for a T3 N1 M0 adenocarcinoma of the upper rectum. The histopathology report describes a moderately differentiated tumour with 3 out of 18 lymph nodes positive for metastatic disease. The circumferential resection margin (CRM) is 8 mm and all margins are clear. According to current UK guidelines, what is the most appropriate adjuvant treatment for this patient?
Q127
A 60-year-old man undergoes elective open mesh repair of a large right indirect inguinal hernia. During the procedure, the surgeon identifies the hernia sac lateral to the inferior epigastric vessels. Which of the following structures forms the medial boundary of the deep inguinal ring through which this hernia originated?
Q128
A 19-year-old woman presents to the emergency department with a 14-hour history of central abdominal pain that has migrated to the right iliac fossa. She has vomited twice and has anorexia. On examination, temperature is 37.8°C, heart rate 92 bpm, and blood pressure 118/72 mmHg. There is tenderness and guarding in the right iliac fossa. Blood tests show: WBC 13.2 × 10⁹/L, CRP 28 mg/L. What is the pathophysiological mechanism responsible for the initial central abdominal pain in acute appendicitis?
Q129
A 58-year-old woman is diagnosed with a T3 N0 M0 (stage IIA) adenocarcinoma of the ascending colon following right hemicolectomy. Histopathology shows moderately differentiated adenocarcinoma with 15 lymph nodes examined (all negative), clear resection margins (>10 mm circumferentially), and no lymphovascular invasion. However, microsatellite instability (MSI) testing demonstrates high-level MSI (MSI-H) with loss of MLH1 and PMS2 expression on immunohistochemistry. BRAF V600E mutation is absent. What is the most appropriate next step in management?
Q130
A 64-year-old man undergoes routine screening colonoscopy and is found to have a 35 mm sessile polyp in the caecum. The lesion is removed by endoscopic submucosal dissection (ESD) en bloc. Histopathology shows a well-differentiated adenocarcinoma invading 1800 μm into the submucosa (sm2), with no lymphovascular invasion and clear resection margins (4 mm). He is otherwise fit and well with no significant comorbidities. At the colorectal MDT meeting, what is the most appropriate management recommendation?
General Surgery UK Medical PG Practice Questions and MCQs
Question 121: A 72-year-old man presents to the colorectal clinic following a screening colonoscopy that identified a 35 mm sessile polyp in the sigmoid colon. The polyp was not removed during colonoscopy due to size and morphology. Subsequent histology from biopsies shows high-grade dysplasia. CT colonography confirms the polyp but no other lesions. What is the most appropriate management for this lesion?
A. Repeat colonoscopy with endoscopic mucosal resection (EMR) of the polyp
B. Arrange endoscopic submucosal dissection (ESD) in a specialist centre (Correct Answer)
C. Proceed directly to sigmoid colectomy given the size and high-grade dysplasia
D. Surveillance colonoscopy in 3 months to assess for progression
E. CT-guided percutaneous biopsy to exclude invasive malignancy before further treatment
Explanation: ***Arrange endoscopic submucosal dissection (ESD) in a specialist centre***
- For **large sessile polyps** (>20 mm, here 35 mm) with **high-grade dysplasia**, ESD allows for **en-bloc resection**, providing a complete specimen for accurate histological assessment of invasion and clear margins.
- This technique significantly reduces the risk of **local recurrence** compared to piecemeal EMR and helps determine if surgical colectomy is truly necessary by accurately staging the lesion for potential **submucosal invasion**.
*Repeat colonoscopy with endoscopic mucosal resection (EMR) of the polyp*
- **Piecemeal EMR** for large sessile polyps, especially those with high-grade dysplasia, is associated with a higher risk of **incomplete resection** and **local recurrence**.
- The fragmented nature of the specimen obtained via piecemeal EMR can make **accurate pathological staging** (e.g., assessing depth of invasion) challenging, potentially missing areas of invasion.
*Proceed directly to sigmoid colectomy given the size and high-grade dysplasia*
- While **high-grade dysplasia** is concerning, directly proceeding to **colectomy** without attempting less invasive endoscopic resection (like ESD) is generally considered an overtreatment, as it carries significantly higher morbidity and mortality.
- Surgery is typically reserved for confirmed **invasive malignancy** or lesions that are definitively not amenable to endoscopic removal due to morphology or suspected deep invasion.
*Surveillance colonoscopy in 3 months to assess for progression*
- Monitoring a 35 mm sessile polyp with **high-grade dysplasia** is inappropriate as it carries a high risk of containing or progressing to **invasive adenocarcinoma** if not treated promptly.
- Such high-risk lesions require **definitive intervention** rather than observation, as delayed treatment can lead to worse outcomes.
*CT-guided percutaneous biopsy to exclude invasive malignancy before further treatment*
- **Percutaneous biopsy** of an intraluminal colorectal lesion is generally contraindicated due to a significant risk of **peritoneal seeding** (spreading cancer cells into the abdominal cavity).
- Moreover, a small biopsy may not capture the most aggressive or invasive part of the lesion, leading to **sampling error** and an underestimation of the true pathological grade or extent of invasion.
Question 122: A 35-year-old man presents with a 40-hour history of right iliac fossa pain, nausea, and fever. CT abdomen demonstrates an inflamed appendix with surrounding fat stranding. During laparoscopic appendicectomy, the appendix base is severely inflamed and friable. After dividing the mesoappendix, the surgeon is unable to securely ligate the appendix base with an endoloop due to tissue quality. What is the most appropriate next step in management?
A. Convert to open appendicectomy via grid-iron incision to allow secure ligation
B. Apply multiple endoloops at the appendix base to ensure secure closure
C. Use an endoscopic linear stapler to divide the appendix base (Correct Answer)
D. Perform a caecectomy to ensure adequate resection margins
E. Leave the appendix in situ and perform peritoneal washout only
Explanation: ***Use an endoscopic linear stapler to divide the appendix base***
- When the appendix base is **severely inflamed and friable**, endoloops are likely to cheese-wire through the tissue; an **endoscopic linear stapler (Endo-GIA)** provides a more secure, wide-surface closure.
- This technique allows for the safe management of **dilated or oedematous appendix bases** while maintaining the benefits of a **laparoscopic approach**.
*Convert to open appendicectomy via grid-iron incision to allow secure ligation*
- Conversion to open surgery should be avoided if the issue can be managed **laparoscopically** with better instrumentation like a stapler.
- A **grid-iron incision** provides limited access and would not necessarily make ligating a **friable appendix base** any safer than using a stapler.
*Apply multiple endoloops at the appendix base to ensure secure closure*
- If the tissue is **friable and poor quality**, adding more loops increases the risk of **tissue strangulation and necrosis** rather than improving security.
- Multiple loops do not address the fundamental issue of **stump leak** risk in severely diseased tissue.
*Perform a caecectomy to ensure adequate resection margins*
- A **caecectomy** (or partial cecectomy) is an aggressive step and is generally reserved for cases where the **caecal wall** itself is necrotic or involved in a tumor.
- It carries significantly higher morbidity, such as **anastomotic leak**, and is unnecessary if the base can be stapled safely.
*Leave the appendix in situ and perform peritoneal washout only*
- Leaving an inflamed, potentially **gangrenous appendix** in situ is inappropriate as it leads to continued **sepsis or abscess formation**.
- Standard surgical practice requires **removal of the source of infection** (appendicectomy) unless a stable inflammatory mass is managed purely conservatively.
Question 123: A 68-year-old man with newly diagnosed sigmoid colon adenocarcinoma undergoes staging investigations. CT chest/abdomen/pelvis shows the primary tumour with invasion through the muscularis propria into the pericolonic fat, 4 enlarged regional lymph nodes, and 3 small (<1 cm) lesions in the right lobe of the liver consistent with metastases. Liver function tests are normal. Carcinoembryonic antigen (CEA) is 85 ng/mL. What is the most appropriate initial management strategy according to current UK colorectal cancer guidelines?
A. Primary tumour resection followed by adjuvant chemotherapy, with liver metastases left untreated
B. Palliative chemotherapy only, as synchronous liver metastases preclude curative treatment
C. Neoadjuvant chemotherapy followed by simultaneous colorectal and liver resection if metastases are resectable (Correct Answer)
D. Liver resection or ablation first, followed by colorectal resection after recovery
E. Palliative stenting of the colon to prevent obstruction, with best supportive care
Explanation: ***Neoadjuvant chemotherapy followed by simultaneous colorectal and liver resection if metastases are resectable***- In cases of **synchronous liver metastases** that are potentially resectable (e.g., small, localized to one lobe), a **multimodal curative approach** is the standard of care.- **Neoadjuvant chemotherapy** is used to treat **micrometastases**, assess tumor biology, and potentially downstage the lesions before attempting **simultaneous or staged resection**.*Primary tumour resection followed by adjuvant chemotherapy, with liver metastases left untreated*- Ignoring resectable liver metastases in **Stage IV colorectal cancer** is inappropriate as it misses a significant opportunity for a **curative-intent treatment**.- Modern guidelines advocate for addressing both the **primary tumor** and **distant metastases** if they are surgically accessible to improve long-term survival.*Palliative chemotherapy only, as synchronous liver metastases preclude curative treatment*- Synchronous liver metastases do not automatically mean the disease is incurable; approximately 30-40% of patients with **resectable liver disease** can achieve **5-year survival**.- Palliative care is reserved for cases where the **metastatic burden** is too high for surgical intervention or the patient's **performance status** is poor.*Liver resection or ablation first, followed by colorectal resection after recovery*- The **'liver-first' approach** is typically reserved for patients where the **metastatic burden** is extremely high or more life-threatening than the primary tumor.- For a patient with an intact sigmoid primary and small liver lesions, **simultaneous resection** or neoadjuvant therapy followed by resection is more standard.*Palliative stenting of the colon to prevent obstruction, with best supportive care*- **Stenting** is a palliative measure for patients who have **obstructive symptoms** and are not candidates for surgery.- Since this patient has potentially **curable metastatic disease** and no mention of acute obstruction, electing for supportive care alone would be clinically incorrect.
Question 124: A 56-year-old woman presents to the emergency department with a 6-hour history of severe pain in her right groin. She has a known right femoral hernia which has always been reducible. On examination, there is a tense, tender mass below and lateral to the pubic tubercle. The overlying skin appears dusky. Heart rate is 105 bpm, temperature 37.9°C. What is the anatomical structure that forms the medial border of the femoral canal and is at risk during repair of this hernia?
A. Femoral vein
B. Inguinal ligament
C. Lacunar ligament (Correct Answer)
D. Pectineal ligament
E. Iliopsoas muscle
Explanation: ***Lacunar ligament***- The **lacunar ligament** (Gimbernat's ligament) forms the **medial border** of the femoral canal and its sharp edge is the primary site of constriction in a **strangulated femoral hernia**.- During emergency surgical repair, this ligament may need to be incised to release the hernia sac, putting an **aberrant obturator artery** (if present) at risk of injury.*Femoral vein*- The **femoral vein** forms the **lateral border** of the femoral canal, which describes its position relative to the hernia sac.- Accidental injury to this structure during repair can lead to significant venous bleeding or thrombosis rather than being the source of constriction.*Inguinal ligament*- The **inguinal ligament** (Poupart's ligament) forms the **anterior border** of the femoral canal.- It is located superior to the femoral hernia sac, as femoral hernias pass **below and lateral** to the pubic tubercle.*Pectineal ligament*- The **pectineal ligament** (Cooper's ligament) forms the **posterior border** of the femoral canal as it overlies the **superior pubic ramus**.- While important for anchoring sutures during various hernia repairs (like a McVay repair), it does not form the medial boundary.*Iliopsoas muscle*- The **iliopsoas muscle** is located much further **laterally** in the retrofascial space and does not form a boundary of the femoral canal.- It is separated from the femoral canal by the **iliopectineal arch** and the femoral vessels.
Question 125: A 43-year-old man presents to the emergency department with a 72-hour history of right lower quadrant pain, fever of 39.1°C, and rigors. CT abdomen and pelvis demonstrates a retrocaecal appendix with surrounding fat stranding and a 6 cm × 5 cm pericaecal collection with gas locules. Blood tests show WBC 16.8 × 10⁹/L, CRP 245 mg/L. The patient has been symptomatic for 4 days. What is the most appropriate initial management strategy?
A. Emergency open appendicectomy via a right iliac fossa incision
B. Immediate laparoscopic appendicectomy with washout
C. CT-guided percutaneous drainage of the abscess followed by interval appendicectomy (Correct Answer)
D. Broad-spectrum intravenous antibiotics alone with interval appendicectomy in 6-8 weeks if symptoms persist
E. Emergency right hemicolectomy to ensure adequate source control
Explanation: ***CT-guided percutaneous drainage of the abscess followed by interval appendicectomy***
- For a **pericaecal collection** (abscess) of this size (6 cm) in a patient symptomatic for more than 72 hours, **percutaneous drainage** combined with antibiotics is the preferred initial management to achieve source control.
- This approach avoids the high morbidity of surgery in a highly **inflamed operative field**, with an **interval appendicectomy** performed later (6–12 weeks) once inflammation resolves.
*Emergency open appendicectomy via a right iliac fossa incision*
- Attempting surgery during the **acute inflammatory phase** of an appendix mass or abscess significantly increases the risk of **ileal injury** and wound infection.
- Open surgery in this setting is associated with higher complication rates compared to **non-operative management** and drainage.
*Immediate laparoscopic appendicectomy with washout*
- **Laparoscopic appendicectomy** in the presence of a well-defined abscess and phlegmon is technically difficult and carries a high risk of **conversion to open surgery**.
- Distorted anatomy due to intense inflammation increases the likelihood of **iatrogenic bowel injury** or the need for more extensive resection.
*Broad-spectrum intravenous antibiotics alone with interval appendicectomy in 6-8 weeks if symptoms persist*
- While small collections can be managed with antibiotics alone, a **6 cm collection** with **gas locules** typically requires active drainage for successful clinical resolution.
- Relying solely on antibiotics for a large abscess increases the risk of **treatment failure** and persistent sepsis.
*Emergency right hemicolectomy to ensure adequate source control*
- A **right hemicolectomy** is an overly aggressive and morbid procedure for uncomplicated appendiceal abscesses, usually reserved for cases of **suspected malignancy** or extensive cecal necrosis.
- Source control can be achieved via less invasive means, such as **percutaneous drainage**, sparing the patient a major bowel resection.
Question 126: A 65-year-old woman undergoes curative anterior resection for a T3 N1 M0 adenocarcinoma of the upper rectum. The histopathology report describes a moderately differentiated tumour with 3 out of 18 lymph nodes positive for metastatic disease. The circumferential resection margin (CRM) is 8 mm and all margins are clear. According to current UK guidelines, what is the most appropriate adjuvant treatment for this patient?
A. Observation with surveillance colonoscopy only
B. Adjuvant chemotherapy with FOLFOX or CAPOX regimen (Correct Answer)
C. Short-course radiotherapy followed by chemotherapy
D. Long-course chemoradiotherapy followed by chemotherapy
E. Adjuvant chemotherapy with single-agent fluorouracil
Explanation: ***Adjuvant chemotherapy with FOLFOX or CAPOX regimen***- In the UK, **Stage III (node-positive)** colorectal cancer requires adjuvant combination chemotherapy to reduce the risk of recurrence and improve **overall survival**.- Regimens such as **FOLFOX** (5-FU, folinic acid, and oxaliplatin) or **CAPOX** (capecitabine and oxaliplatin) are the standard of care for patients with good performance status.*Observation with surveillance colonoscopy only*- Observation alone is insufficient for **Stage III (T3 N1)** disease because the presence of **lymph node metastasis** significantly increases the risk of systemic recurrence.- This approach is typically reserved for **Stage I** disease or low-risk Stage II disease where the benefit of chemotherapy is marginal.*Short-course radiotherapy followed by chemotherapy*- Radiotherapy is a **neoadjuvant** (pre-operative) treatment used to downstage tumours or reduce local recurrence risk; it is not routinely used in the **post-operative (adjuvant)** setting for clear margins.- Because the **circumferential resection margin (CRM)** is 8 mm (well above the 1 mm threshold), there is no indication for further local radiotherapy.*Long-course chemoradiotherapy followed by chemotherapy*- Similar to short-course treatment, **chemoradiotherapy** is primarily a pre-operative strategy for locally advanced rectal cancers to improve **resectability**.- Since the patient has already undergone a curative resection with **clear margins**, the focus shifts exclusively to systemic chemotherapy to target potential **micrometastases**.*Adjuvant chemotherapy with single-agent fluorouracil*- Single-agent therapy (like **Capecitabine** or **5-FU**) is generally considered less effective than combination therapy for node-positive (Stage III) disease.- **Oxaliplatin-based combinations** are preferred in this age group unless there are specific contraindications, such as severe **peripheral neuropathy** or significant comorbidities.
Question 127: A 60-year-old man undergoes elective open mesh repair of a large right indirect inguinal hernia. During the procedure, the surgeon identifies the hernia sac lateral to the inferior epigastric vessels. Which of the following structures forms the medial boundary of the deep inguinal ring through which this hernia originated?
A. Conjoint tendon
B. Inferior epigastric vessels (Correct Answer)
C. Inguinal ligament
D. Rectus abdominis muscle
E. Lateral border of rectus sheath
Explanation: ***Inferior epigastric vessels***
- The **deep inguinal ring** is an opening in the **transversalis fascia** located lateral to the **inferior epigastric vessels**, which serve as its primary medial boundary.
- An **indirect inguinal hernia** originates through this ring, meaning its sac passes **lateral** to these vessels as it enters the inguinal canal.
*Conjoint tendon*
- The **conjoint tendon** is formed by the fusion of the internal oblique and **transversus abdominis** muscles, contributing to the posterior wall of the inguinal canal medially.
- It is located medial to the deep inguinal ring and is more relevant to the posterior wall, particularly in the context of direct hernias.
*Inguinal ligament*
- The **inguinal ligament** (Poupart's ligament) forms the **floor** of the inguinal canal, extending from the anterior superior iliac spine to the pubic tubercle.
- It serves as a crucial anatomical landmark, separating inguinal hernias (above) from **femoral hernias** (below).
*Rectus abdominis muscle*
- This muscle forms the **medial border** of **Hesselbach's triangle**, an area of weakness where **direct inguinal hernias** protrude.
- It is anatomically more medial and anterior than the deep inguinal ring, thus not forming its boundary.
*Lateral border of rectus sheath*
- The **lateral border of the rectus sheath** is synonymous with the lateral border of the rectus abdominis muscle and also defines the medial boundary of **Hesselbach's triangle**.
- It is not a direct boundary of the **deep inguinal ring**, which is situated more laterally and superiorly.
Question 128: A 19-year-old woman presents to the emergency department with a 14-hour history of central abdominal pain that has migrated to the right iliac fossa. She has vomited twice and has anorexia. On examination, temperature is 37.8°C, heart rate 92 bpm, and blood pressure 118/72 mmHg. There is tenderness and guarding in the right iliac fossa. Blood tests show: WBC 13.2 × 10⁹/L, CRP 28 mg/L. What is the pathophysiological mechanism responsible for the initial central abdominal pain in acute appendicitis?
A. Irritation of the parietal peritoneum by the inflamed appendix
B. Visceral pain from distension and stretching of the appendiceal wall transmitted via sympathetic fibres (Correct Answer)
C. Direct stimulation of somatic pain receptors in the anterior abdominal wall
D. Release of inflammatory mediators causing peritoneal inflammation
E. Spasm of the iliopsoas muscle due to local inflammation
Explanation: ***Visceral pain from distension and stretching of the appendiceal wall transmitted via sympathetic fibres***- The initial **periumbilical** or central pain is **visceral**, triggered by luminal obstruction and subsequent **distension** of the appendiceal wall.- This pain is conducted via **afferent sympathetic fibres** entering the spinal cord at the **T10 level**, resulting in poorly localized midline pain.*Irritation of the parietal peritoneum by the inflamed appendix*- This mechanism is responsible for the later **somatic pain** which is sharply localized to the **right iliac fossa** (McBurney's point).- It occurs only after the inflammatory process extends beyond the organ to contact the **parietal peritoneum**.*Direct stimulation of somatic pain receptors in the anterior abdominal wall*- Somatic receptors provide **well-localized** sensation and are not involved in the initial **vague central pain** phase.- Somatic stimulation leads to signs like **guarding** and **rebound tenderness**, which characterize later stages.*Release of inflammatory mediators causing peritoneal inflammation*- While mediators drive the progression of the disease, the **initial pain** is mechanical due to **obstruction and distension**.- Peritoneal inflammation results in **localized pain**, not the migrating periumbilical pain described in early appendicitis.*Spasm of the iliopsoas muscle due to local inflammation*- This describes the **Psoas sign**, which suggests an inflamed appendix is located in a **retrocaecal position**.- It is a physical examination finding of **localized irritation** rather than the mechanism for early-stage central pain.
Question 129: A 58-year-old woman is diagnosed with a T3 N0 M0 (stage IIA) adenocarcinoma of the ascending colon following right hemicolectomy. Histopathology shows moderately differentiated adenocarcinoma with 15 lymph nodes examined (all negative), clear resection margins (>10 mm circumferentially), and no lymphovascular invasion. However, microsatellite instability (MSI) testing demonstrates high-level MSI (MSI-H) with loss of MLH1 and PMS2 expression on immunohistochemistry. BRAF V600E mutation is absent. What is the most appropriate next step in management?
A. Routine surveillance only as stage II colon cancer does not require adjuvant chemotherapy
B. Refer for genetic counselling and germline testing for Lynch syndrome
C. Commence adjuvant chemotherapy with FOLFOX as MSI-H indicates poor prognosis
D. Arrange upper GI endoscopy and urological screening for synchronous malignancies
E. Perform MLH1 promoter hypermethylation testing before further management decisions (Correct Answer)
Explanation: ***Perform MLH1 promoter hypermethylation testing before further management decisions*** - The patient has an **MSI-H tumour** with loss of **MLH1** and **PMS2**; in the absence of a **BRAF V600E mutation**, the next step is to differentiate between **sporadic hypermethylation** and **Lynch syndrome**. - Identifying **MLH1 promoter hypermethylation** establishes the cancer as sporadic, whereas its absence strongly indicates the need for **germline testing** for Lynch syndrome. *Routine surveillance only as stage II colon cancer does not require adjuvant chemotherapy* - While **MSI-H** status in stage II generally predicts a **favorable prognosis** and lack of benefit from **5-FU monotherapy**, surveillance alone is insufficient until **Lynch syndrome** is ruled out. - Confirming or excluding Lynch syndrome is crucial, as it impacts the patient's long-term **surveillance strategy** and necessitates **cascade testing** for at-risk family members. *Refer for genetic counselling and germline testing for Lynch syndrome* - This referral is premature because approximately 60% of tumors with **MLH1** loss of expression are due to **sporadic hypermethylation** rather than Lynch syndrome, even in the absence of a **BRAF mutation**. - **Germline testing** for Lynch syndrome should only be considered after **MLH1 promoter hypermethylation** has been definitively excluded as a cause for the MLH1 deficiency. *Commence adjuvant chemotherapy with FOLFOX as MSI-H indicates poor prognosis* - This statement is incorrect; **MSI-H** colon cancers in Stage II actually have a **better prognosis** compared to microsatellite stable (MSS) tumours. - Adjuvant chemotherapy with **fluoropyrimidines** is generally **not recommended** for Stage II MSI-H patients due to a lack of significant benefit and a low risk of recurrence. *Arrange upper GI endoscopy and urological screening for synchronous malignancies* - While **Lynch syndrome** is associated with an increased risk of **extracolonic malignancies** such as **gastric**, **urothelial**, and **endometrial cancers**, a definitive diagnosis of Lynch syndrome has not yet been established. - Screening protocols for synchronous or metachronous tumours are initiated only after a confirmed diagnosis of **Lynch syndrome** through **germline genetic testing`**.
Question 130: A 64-year-old man undergoes routine screening colonoscopy and is found to have a 35 mm sessile polyp in the caecum. The lesion is removed by endoscopic submucosal dissection (ESD) en bloc. Histopathology shows a well-differentiated adenocarcinoma invading 1800 μm into the submucosa (sm2), with no lymphovascular invasion and clear resection margins (4 mm). He is otherwise fit and well with no significant comorbidities. At the colorectal MDT meeting, what is the most appropriate management recommendation?
A. Surveillance colonoscopy at 3 months to assess the resection site, then annual surveillance for 5 years
B. Right hemicolectomy with regional lymphadenectomy should be offered given the depth of invasion (Correct Answer)
C. CT surveillance at 6-monthly intervals for 2 years as the risk of nodal disease is low
D. Adjuvant chemotherapy with capecitabine for 3 months followed by surveillance
E. No further treatment required; routine surveillance colonoscopy at 1 year
Explanation: ***Right hemicolectomy with regional lymphadenectomy should be offered given the depth of invasion***- In **pT1 colorectal cancer**, a depth of submucosal invasion exceeding **1000 μm (Kikuchi sm2/sm3)** is a significant risk factor for **lymph node metastasis (LNM)**.- This patient's invasion depth of **1800 μm** and fit status make him a candidate for formal oncological resection to ensure adequate **lymphadenectomy**, as the risk of nodal disease outweighs surgical risk.*Surveillance colonoscopy at 3 months to assess the resection site, then annual surveillance for 5 years*- While surveillance is used for benign polyps, it is insufficient for a malignant polyp with **submucosal invasion depth >1000 μm** due to the risk of occult nodal disease.- **Endoscopic surveillance** only monitors for local recurrence and cannot detect or treat metastases in the **regional lymph nodes**.*CT surveillance at 6-monthly intervals for 2 years as the risk of nodal disease is low*- The risk of nodal disease in **sm2/sm3 lesions** is approximately 8-23%, which is high enough to warrant surgical intervention rather than just imaging.- **CT scanning** has limited sensitivity for detecting small-volume **nodal metastases** in early-stage colorectal cancer.*Adjuvant chemotherapy with capecitabine for 3 months followed by surveillance*- **Adjuvant chemotherapy** is typically reserved for Stage III (node-positive) or high-risk Stage II disease, not for isolated **pT1 lesions**.- The primary concern here is the potential for **lymph node involvement**, which requires surgical staging and resection rather than systemic therapy.*No further treatment required; routine surveillance colonoscopy at 1 year*- This approach is only appropriate for **low-risk pT1 cancers** (sm1 invasion <1000 μm, well-differentiated, no LVI, and clear margins).- Ignoring the **1800 μm invasion depth** overlooks a high-risk feature that significantly increases the likelihood of **regional recurrence** and mortality.
