A 67-year-old man with a BMI of 42 kg/m² undergoes emergency laparotomy for perforated diverticulitis. A Hartmann's procedure is performed. On post-operative day 4, he develops sudden onset severe abdominal pain and distension. Examination reveals diffuse abdominal tenderness with absent bowel sounds. His observations show: HR 115 bpm, BP 95/60 mmHg, temperature 37.8°C, respiratory rate 24/min, oxygen saturations 92% on air. Abdominal X-ray shows massively dilated colon (caecal diameter 13 cm). What is the most likely diagnosis?
Q82
A 62-year-old man presents with a 24-hour history of severe constant right upper quadrant pain, fever of 38.7°C, and jaundice. He has a history of gallstones diagnosed 2 years ago but declined cholecystectomy. Blood tests show: WBC 18.2 × 10⁹/L, CRP 245 mg/L, bilirubin 95 μmol/L, ALT 180 U/L, ALP 420 U/L. Ultrasound shows gallbladder wall thickening, pericholecystic fluid, and dilated common bile duct measuring 9 mm with a stone in the distal CBD. What is the most appropriate immediate management?
Q83
A 54-year-old woman presents with a 4-day history of cramping abdominal pain and distension. She has not opened her bowels for 5 days. She has a history of endometriosis and underwent total abdominal hysterectomy 5 years ago. Examination reveals a distended abdomen with active high-pitched bowel sounds. CT abdomen shows dilated small bowel loops up to 3.8 cm with decompressed loops distally. A transition point is identified with a 'whirl sign' at the site of obstruction. What is the most likely underlying cause of her presentation?
Q84
What is the most common microorganism isolated in secondary bacterial peritonitis following colonic perforation?
Q85
A 70-year-old man with a history of three previous laparotomies for various abdominal pathologies presents with a 48-hour history of colicky central abdominal pain, vomiting, and absolute constipation. CT abdomen shows multiple dilated loops of small bowel (maximum diameter 4.5 cm) with a transition point in the mid-ileum. There is no free fluid or bowel wall thickening. He is commenced on conservative management with IV fluids, nil by mouth, and nasogastric decompression. After 72 hours of conservative management, his symptoms persist unchanged. What is the most appropriate next step in management?
Q86
A 58-year-old woman presents to the emergency department with a 12-hour history of sudden onset severe epigastric pain. She has a history of type 2 diabetes and takes metformin. On examination, her abdomen is rigid with guarding and rebound tenderness throughout. An erect chest radiograph shows free air under both hemidiaphragms. Which of the following is the most appropriate initial management?
Q87
A 48-year-old man with ulcerative colitis presents with a 4-day history of increasing bloody diarrhoea (12 motions per day), abdominal pain, and fever. He appears unwell with temperature 38.6°C, heart rate 125 bpm, blood pressure 105/68 mmHg. Blood tests show: Hb 92 g/L, WCC 18.7 × 10⁹/L, CRP 245 mg/L, albumin 24 g/L. Plain abdominal radiograph shows colonic dilatation with the transverse colon measuring 7.5 cm in diameter. He is commenced on IV hydrocycortisone and antibiotics. After 48 hours of medical management, his symptoms persist with ongoing high fever and eight bloody stools in 24 hours. What is the most appropriate next step?
Q88
What is the Mannheim Peritonitis Index (MPI) and what is its primary clinical utility in the management of patients with peritonitis?
Q89
A 55-year-old man with no previous medical history presents with a 72-hour history of central colicky abdominal pain, distension, and vomiting. He has not had a bowel motion for 48 hours. Plain abdominal radiograph shows dilated small bowel loops with valvulae conniventes visible. No previous surgical scars are noted. CT abdomen demonstrates a transition point in the mid-ileum with a fat-containing mass causing intussusception. What is the most likely underlying diagnosis?
Q90
A 69-year-old woman with rheumatoid arthritis maintained on methotrexate and prednisolone 15mg daily presents with a 24-hour history of worsening abdominal pain and distension. She appears septic with temperature 38.7°C, heart rate 118 bpm, blood pressure 92/55 mmHg. Examination reveals generalized peritonism. CT abdomen shows pneumoperitoneum with free fluid, but no obvious site of perforation is identified. Serum lactate is 4.8 mmol/L. At laparotomy, two small jejunal perforations are found with minimal surrounding inflammation. What is the most likely underlying cause?
Acute Surgical Presentations UK Medical PG Practice Questions and MCQs
Question 81: A 67-year-old man with a BMI of 42 kg/m² undergoes emergency laparotomy for perforated diverticulitis. A Hartmann's procedure is performed. On post-operative day 4, he develops sudden onset severe abdominal pain and distension. Examination reveals diffuse abdominal tenderness with absent bowel sounds. His observations show: HR 115 bpm, BP 95/60 mmHg, temperature 37.8°C, respiratory rate 24/min, oxygen saturations 92% on air. Abdominal X-ray shows massively dilated colon (caecal diameter 13 cm). What is the most likely diagnosis?
A. Anastomotic leak
B. Acute colonic pseudo-obstruction (Ogilvie's syndrome) (Correct Answer)
C. Mechanical large bowel obstruction from adhesions
D. Paralytic ileus
E. Ischaemic colitis
Explanation: ***Acute colonic pseudo-obstruction (Ogilvie's syndrome)***
- This patient exhibits **massive colonic dilatation** (caecum 13 cm) without a mechanical cause, characteristic of **Ogilvie's syndrome**, which often occurs 3-5 days after major abdominal surgery.
- The combination of **obesity**, recent **emergency laparotomy**, and potential **electrolyte imbalances** or opioid use are significant risk factors for this autonomic dysfunction of the colon.
*Anastomotic leak*
- An **anastomotic leak** is impossible in this clinical scenario because a **Hartmann's procedure** involves creating an end colostomy and a closed rectal stump, meaning no anastomosis was performed.
- While the patient is unwell, the primary imaging finding of massive colonic distension points away from a simple stump blowout.
*Mechanical large bowel obstruction from adhesions*
- While **mechanical obstruction** causes dilatation, it usually occurs later in the postoperative period and requires a physical **transition point** to be seen on imaging.
- In this patient, the acute presentation on POD 4 with a massively dilated caecum is more consistent with a functional pseudo-obstruction than early fibrous **adhesions**.
*Paralytic ileus*
- **Paralytic ileus** typically manifests as generalized dilatation of both the **small and large bowel**, rather than the isolated, massive colonic distension seen here.
- While similar in pathophysiology, the specific term and severity (caecal diameter >12 cm) in the colon define **pseudo-obstruction** rather than simple post-operative ileus.
*Ischaemic colitis*
- **Ischaemic colitis** typically presents with bloody diarrhea and imaging signs such as **bowel wall thickening** or "thumbprinting," which are not described.
- Although the patient is hypotensive, the primary finding is massive gaseous distension (13 cm), which is the hallmark of **colonic pseudo-obstruction** rather than primary vascular compromise.
Question 82: A 62-year-old man presents with a 24-hour history of severe constant right upper quadrant pain, fever of 38.7°C, and jaundice. He has a history of gallstones diagnosed 2 years ago but declined cholecystectomy. Blood tests show: WBC 18.2 × 10⁹/L, CRP 245 mg/L, bilirubin 95 μmol/L, ALT 180 U/L, ALP 420 U/L. Ultrasound shows gallbladder wall thickening, pericholecystic fluid, and dilated common bile duct measuring 9 mm with a stone in the distal CBD. What is the most appropriate immediate management?
A. Emergency cholecystectomy within 6 hours
B. IV antibiotics, fluid resuscitation, and urgent ERCP within 24 hours (Correct Answer)
C. Conservative management with IV antibiotics and elective ERCP in 2-3 days
D. Percutaneous cholecystostomy
E. IV antibiotics and emergency laparotomy with CBD exploration
Explanation: ***IV antibiotics, fluid resuscitation, and urgent ERCP within 24 hours***- The patient presents with **Charcot’s triad** (fever, jaundice, RUQ pain), elevated inflammatory markers, and a distal CBD stone, indicating **acute cholangitis**, which requires prompt **biliary decompression**.- **Urgent ERCP** is the gold standard for relieving biliary obstruction due to choledocholithiasis, while **IV antibiotics** and **fluid resuscitation** manage systemic infection and support hemodynamic stability.*Emergency cholecystectomy within 6 hours*- Cholecystectomy addresses the gallbladder but does not relieve the **common bile duct obstruction** caused by the stone, which is the root cause of the cholangitis and sepsis.- Performing major surgery on an acutely septic and jaundiced patient with cholangitis carries a significantly higher risk of **morbidity and mortality** compared to initial biliary decompression.*Conservative management with IV antibiotics and elective ERCP in 2-3 days*- Acute cholangitis is a medical emergency that can rapidly progress to **septic shock** if biliary obstruction and infection persist without prompt drainage.- Delaying biliary decompression for 2-3 days is inappropriate for **moderate-to-severe cholangitis**, where urgent intervention is crucial to prevent worsening sepsis and organ failure.*Percutaneous cholecystostomy*- This procedure drains the **gallbladder** and is primarily indicated for acute cholecystitis in patients unfit for surgery, but it does not resolve **common bile duct obstruction**.- As the pathology is a **distal CBD stone** causing cholangitis, a cholecystostomy would not achieve effective biliary drainage or resolve the patient's jaundice.*IV antibiotics and emergency laparotomy with CBD exploration*- **Laparotomy with CBD exploration** is an invasive surgical approach for choledocholithiasis that has largely been replaced by less invasive **ERCP** in most cases.- In an acutely ill, elderly patient with cholangitis, **endoscopic management** carries a lower risk profile and faster recovery compared to open surgical exploration.
Question 83: A 54-year-old woman presents with a 4-day history of cramping abdominal pain and distension. She has not opened her bowels for 5 days. She has a history of endometriosis and underwent total abdominal hysterectomy 5 years ago. Examination reveals a distended abdomen with active high-pitched bowel sounds. CT abdomen shows dilated small bowel loops up to 3.8 cm with decompressed loops distally. A transition point is identified with a 'whirl sign' at the site of obstruction. What is the most likely underlying cause of her presentation?
A. Adhesional band causing simple obstruction
B. Internal hernia with closed-loop obstruction (Correct Answer)
C. Intussusception
D. Small bowel malignancy
E. Stricture from Crohn's disease
Explanation: ***Internal hernia with closed-loop obstruction***- The presence of a **'whirl sign'** on CT is a pathognomonic finding indicating the rotation of the mesentery and bowel around a fixed point, highly characteristic of a **volvulus** or **internal hernia**.- This patient’s history of a **total abdominal hysterectomy** significantly increases the risk for internal hernias through surgical defects, leading to a dangerous **closed-loop obstruction** with high strangulation risk.*Adhesional band causing simple obstruction*- While **adhesions** are the most common cause of bowel obstruction post-surgery, they typically present with a simple transition point without rotational mesenteric twisting.- A **simple obstruction** does not produce the specific **'whirl sign'** seen on the CT scan in this presentation.*Intussusception*- Adult **intussusception** is usually associated with a lead point and classically displays a **'target sign'** or 'sausage-shaped' mass on imaging rather than a whirl.- It involves the teloscoping of one bowel segment into another, which differs from the **mesenteric twisting** suggested by the CT findings.*Small bowel malignancy*- Malignancy typically manifests as an **enhancing mass lesion**, irregular luminal narrowing, or a 'shoulder sign' at the site of obstruction.- This diagnosis would not explain the **whirl sign**, which specifically represents **vascular and mesenteric torsion**.*Stricture from Crohn's disease**- **Crohn's disease** strictures are characterized by **bowel wall thickening**, mucosal hyperenhancement, and 'comb sign' (engorged vasa recta) rather than a whirl sign.- The patient lacks a history of **chronic diarrhea** or systemic inflammatory symptoms typical of **inflammatory bowel disease**.
Question 84: What is the most common microorganism isolated in secondary bacterial peritonitis following colonic perforation?
A. Staphylococcus aureus
B. Escherichia coli (Correct Answer)
C. Bacteroides fragilis
D. Pseudomonas aeruginosa
E. Enterococcus faecalis
Explanation: ***Escherichia coli***
- **Escherichia coli** is the most frequently isolated aerobic pathogen in secondary bacterial peritonitis, identified in approximately **60-80%** of cases following colonic perforation.
- It represents the predominant **Gram-negative aerobe** within the gut flora that invades the peritoneal cavity when the anatomical barrier is breached.
*Staphylococcus aureus*
- This organism is rarely the primary cause of peritonitis from a hollow viscus perforation; it is more common in **peritoneal dialysis-associated peritonitis**.
- It is a **Gram-positive coccus** typically associated with skin flora or hematogenous spread rather than colonic leakage.
*Bacteroides fragilis*
- While it is the **most common anaerobe** isolated (found in 40-70% of cases), it is overall less frequent than **Escherichia coli** in most culture series.
- It plays a critical role in **abscess formation** and requires specific anaerobic coverage during empirical treatment.
*Pseudomonas aeruginosa*
- This pathogen is not part of the standard colonic flora in healthy individuals and is infrequently isolated in **community-acquired** secondary peritonitis.
- It is more commonly associated with **healthcare-associated infections** or cases involving **immunocompromised patients**.
*Enterococcus faecalis*
- Although it is a common inhabitant of the gastrointestinal tract, its isolation rate in secondary peritonitis is significantly lower than that of **E. coli**.
- It is often isolated as part of a **polymicrobial infection**, but its specific role as a primary driver of the inflammatory response in simple perforation is less dominant.
Question 85: A 70-year-old man with a history of three previous laparotomies for various abdominal pathologies presents with a 48-hour history of colicky central abdominal pain, vomiting, and absolute constipation. CT abdomen shows multiple dilated loops of small bowel (maximum diameter 4.5 cm) with a transition point in the mid-ileum. There is no free fluid or bowel wall thickening. He is commenced on conservative management with IV fluids, nil by mouth, and nasogastric decompression. After 72 hours of conservative management, his symptoms persist unchanged. What is the most appropriate next step in management?
A. Continue conservative management for another 48 hours as some adhesional obstruction resolves within 5 days
B. Water-soluble contrast study to assess the likelihood of spontaneous resolution (Correct Answer)
C. Emergency laparotomy within 6 hours
D. Diagnostic laparoscopy with intention to convert to laparotomy if needed
E. Colonoscopy to exclude malignancy
Explanation: ***Water-soluble contrast study to assess the likelihood of spontaneous resolution***
- A **water-soluble contrast study** (e.g., Gastrografin) is both diagnostic and therapeutic; it helps predict the need for surgery and may stimulate **bowel motility** to resolve the obstruction.
- Current guidelines recommend this step when **conservative management** fails to show progress after 48-72 hours in hemodynamically stable patients without evidence of **strangulation**.
*Continue conservative management for another 48 hours as some adhesional obstruction resolves within 5 days*
- While some cases resolve late, waiting beyond **72 hours** without objective evidence of progress increases the risk of complications and hospital stay.
- Clinical improvement should typically be evident within the first **48-72 hours** if conservative therapy is going to be successful.
*Emergency laparotomy within 6 hours*
- Immediate surgery is reserved for patients with signs of **bowel strangulation**, **ischemia**, or **peritonitis**, which are not present in this stable patient.
- Given the history of **three previous laparotomies**, surgical intervention should be carefully considered due to the likelihood of complex **adhesions**.
*Diagnostic laparoscopy with intention to convert to laparotomy if needed*
- Laparoscopy is difficult in patients with **multiple previous surgeries** and significantly **dilated bowel loops** due to the high risk of **inflicted enterotomy**.
- It is not the preferred next step before attempting to confirm if the obstruction is truly high-grade or complete via **contrast studies**.
*Colonoscopy to exclude malignancy*
- The CT scan confirmed a **small bowel obstruction** with a transition point in the **mid-ileum**, making large bowel malignancy an unlikely cause.
- Colonoscopy is contraindicated and useless in the acute phase of a **small bowel obstruction** as it cannot reach or visualize the site of the pathology.
Question 86: A 58-year-old woman presents to the emergency department with a 12-hour history of sudden onset severe epigastric pain. She has a history of type 2 diabetes and takes metformin. On examination, her abdomen is rigid with guarding and rebound tenderness throughout. An erect chest radiograph shows free air under both hemidiaphragms. Which of the following is the most appropriate initial management?
A. CT abdomen with oral and IV contrast
B. Immediate laparotomy
C. Nil by mouth, IV fluids, broad-spectrum antibiotics, and urgent surgical review (Correct Answer)
D. Upper GI endoscopy
E. Conservative management with proton pump inhibitors
Explanation: ***Nil by mouth, IV fluids, broad-spectrum antibiotics, and urgent surgical review***
- The patient's presentation with sudden severe epigastric pain, **rigid abdomen**, **guarding**, **rebound tenderness**, and **free air under both hemidiaphragms** (pneumoperitoneum) is highly indicative of a **perforated hollow viscus**, a surgical emergency.
- Initial management focuses on **resuscitation** and preparing for surgery: **nil by mouth (NPO)** prevents further GI contents from entering the peritoneum, **IV fluids** address hypovolemia and shock, **broad-spectrum antibiotics** cover potential infection, and **urgent surgical review** is crucial for definitive intervention.
*CT abdomen with oral and IV contrast*
- While a CT scan can provide more detail, the diagnosis of a **perforated viscus** is already strongly established by the clinical picture and **pneumoperitoneum** on plain radiograph, making it unnecessary as the *initial* step.
- **Oral contrast** is contraindicated in suspected perforation as it can leak into the peritoneal cavity, causing a **chemical peritonitis** or obscuring further diagnostic findings during surgery.
*Immediate laparotomy*
- Although surgery is ultimately required, a truly **"immediate" laparotomy** without adequate patient **resuscitation** and preparation can significantly increase **perioperative risks** and morbidity, especially in an acutely unwell patient.
- **Fluid resuscitation**, broad-spectrum antibiotics, and surgical consultation should occur concurrently or prior to the definitive incision to optimize the patient's condition.
*Upper GI endoscopy*
- **Upper GI endoscopy** is absolutely **contraindicated** in cases of suspected or confirmed hollow viscus perforation.
- Insufflation of air during the procedure could exacerbate the **pneumoperitoneum**, potentially leading to **tension pneumoperitoneum** or worsening the peritoneal contamination.
*Conservative management with proton pump inhibitors*
- This approach is completely **inappropriate** and dangerous for a patient with clear signs of **peritonitis** and a **perforated viscus**.
- **Conservative management** would lead to uncontrolled sepsis, multi-organ failure, and likely death in this acute surgical emergency.
Question 87: A 48-year-old man with ulcerative colitis presents with a 4-day history of increasing bloody diarrhoea (12 motions per day), abdominal pain, and fever. He appears unwell with temperature 38.6°C, heart rate 125 bpm, blood pressure 105/68 mmHg. Blood tests show: Hb 92 g/L, WCC 18.7 × 10⁹/L, CRP 245 mg/L, albumin 24 g/L. Plain abdominal radiograph shows colonic dilatation with the transverse colon measuring 7.5 cm in diameter. He is commenced on IV hydrocycortisone and antibiotics. After 48 hours of medical management, his symptoms persist with ongoing high fever and eight bloody stools in 24 hours. What is the most appropriate next step?
A. Add infliximab rescue therapy
B. Continue current management for a further 24-48 hours
C. Emergency subtotal colectomy with end ileostomy (Correct Answer)
D. Flexible sigmoidoscopy with biopsy
E. Add ciclosporin therapy
Explanation: ***Emergency subtotal colectomy with end ileostomy***
- The patient presents with **toxic megacolon** (transverse colon 7.5 cm) and persistent severe symptoms, including high fever and ongoing bloody stools, despite **48 hours of intensive IV corticosteroid and antibiotic therapy**. This indicates failure of medical management and a high risk of perforation.
- Given the lack of clinical improvement and the presence of colonic dilatation, surgical intervention with an **emergency subtotal colectomy** is the most appropriate next step to prevent life-threatening complications like perforation and sepsis.
*Add infliximab rescue therapy*
- While **infliximab** is a rescue therapy for steroid-refractory acute severe ulcerative colitis, it is generally considered after 72 hours of failed IV steroids, and its use is more cautious in the presence of **toxic megacolon** that has not responded to initial treatment.
- Pursuing further medical therapy in a patient with **toxic megacolon** and systemic toxicity who is not improving can delay definitive treatment and increase the risk of bowel perforation and mortality.
*Continue current management for a further 24-48 hours*
- The patient has already failed **48 hours of maximal medical therapy** (IV steroids and antibiotics) and shows no signs of improvement, with persistent fever, tachycardia, and a dilated colon.
- Continuing the same management in this setting would be unsafe and likely to lead to further deterioration, increasing the risk of **colonic perforation** and other serious complications.
*Flexible sigmoidoscopy with biopsy*
- **Flexible sigmoidoscopy** and colonoscopy are **contraindicated** in the setting of **toxic megacolon** due to the significantly increased risk of iatrogenic **bowel perforation**.
- The diagnosis of a severe ulcerative colitis flare with toxic megacolon is already established clinically and radiologically, making further endoscopic evaluation unnecessary and hazardous.
*Add ciclosporin therapy*
- **Ciclosporin** is another alternative rescue therapy for steroid-refractory acute severe ulcerative colitis, similar to infliximab.
- However, in a patient with **toxic megacolon** who has failed initial aggressive medical management and shows no improvement, adding another medical immunosuppressant carries a high risk of failure and delays the necessary definitive surgical intervention.
Question 88: What is the Mannheim Peritonitis Index (MPI) and what is its primary clinical utility in the management of patients with peritonitis?
A. A scoring system to determine the optimal timing for closure of open abdomen in damage control surgery
B. A prognostic scoring system that predicts mortality risk in patients undergoing surgery for peritonitis based on pre-operative and intra-operative factors (Correct Answer)
C. A diagnostic tool to differentiate between perforated peptic ulcer and perforated appendicitis
D. A classification system for different types of peritonitis (primary, secondary, tertiary)
E. A clinical decision tool to determine whether laparoscopic or open surgical approach should be used
Explanation: ***A prognostic scoring system that predicts mortality risk in patients undergoing surgery for peritonitis based on pre-operative and intra-operative factors***
- The **Mannheim Peritonitis Index (MPI)** is a validated tool that uses eight clinical and operative variables to calculate a score correlating directly with **mortality rates**.
- Factors include **age >65**, **organ failure**, **malignancy**, and the **nature of the peritoneal fluid** (e.g., cloudy/purulent vs. fecal).
*A scoring system to determine the optimal timing for closure of open abdomen in damage control surgery*
- Timing for **fascial closure** is typically guided by the resolution of **bowel edema** and the **primary surgery indication**, not the MPI.
- MPI focuses on **survival probability** rather than specific technical timelines for wound management.
*A diagnostic tool to differentiate between perforated peptic ulcer and perforated appendicitis*
- MPI is a **prognostic index**, not a differential diagnosis tool for identifying the **anatomical source** of sepsis.
- **Imaging studies** (like CT) and **clinical examination** are used to differentiate the site of perforation.
*A classification system for different types of peritonitis (primary, secondary, tertiary)*
- Classification into **primary, secondary, or tertiary peritonitis** is a separate pathophysiological categorization based on the **mechanism of infection**.
- MPI is applied specifically to **risk-stratify** patients regardless of these broad classifications.
*A clinical decision tool to determine whether laparoscopic or open surgical approach should be used*
- The choice of **surgical approach** (laparoscopic vs. open) depends on **hemodynamic stability** and surgeon expertise, not the MPI score.
- While MPI helps predict **post-operative outcomes**, it does not mandate a specific **surgical technique**.
Question 89: A 55-year-old man with no previous medical history presents with a 72-hour history of central colicky abdominal pain, distension, and vomiting. He has not had a bowel motion for 48 hours. Plain abdominal radiograph shows dilated small bowel loops with valvulae conniventes visible. No previous surgical scars are noted. CT abdomen demonstrates a transition point in the mid-ileum with a fat-containing mass causing intussusception. What is the most likely underlying diagnosis?
A. Meckel's diverticulum
B. Small bowel lymphoma
C. Lipoma acting as lead point (Correct Answer)
D. Adhesions from previous appendicectomy
E. Carcinoid tumour
Explanation: ***Lipoma acting as lead point***
- The CT finding of a **fat-containing mass** in the mid-ileum, which is causing intussusception, is highly characteristic of a **lipoma**.
- In adults, **intussusception** is usually secondary to a **pathological lead point**, and a lipoma is a common benign tumor that can serve this mechanical role.
*Meckel's diverticulum*
- While it can act as a lead point for **intussusception**, a Meckel's diverticulum is a **blind-ending pouch** of bowel wall, not typically described as a fat-containing mass.
- It often contains **ectopic gastric or pancreatic tissue**, not predominantly adipose tissue, which differentiates it from a lipoma.
*Small bowel lymphoma*
- Small bowel lymphoma typically presents as **segmental wall thickening**, a discrete **soft tissue mass**, or aneurysmal dilatation, but not usually as a fat-containing lesion.
- The absence of a fat density and common systemic symptoms (e.g., weight loss, night sweats) makes lymphoma less likely given the specific imaging finding.
*Adhesions from previous appendicectomy*
- The patient history explicitly states **"No previous surgical scars are noted"**, which effectively rules out postoperative adhesions as a cause of obstruction.
- Adhesions typically cause **extrinsic compression** or kinking of the bowel, rather than an intraluminal fat-containing mass acting as an intussusception lead point.
*Carcinoid tumour*
- Carcinoid tumors are **neuroendocrine tumors** that appear as **hyperenhancing soft tissue masses** on CT and are often associated with a characteristic **desmoplastic reaction** (fibrosis) in the mesentery.
- They do not typically present as a purely fat-containing mass, which is a key differentiating feature in this case.
Question 90: A 69-year-old woman with rheumatoid arthritis maintained on methotrexate and prednisolone 15mg daily presents with a 24-hour history of worsening abdominal pain and distension. She appears septic with temperature 38.7°C, heart rate 118 bpm, blood pressure 92/55 mmHg. Examination reveals generalized peritonism. CT abdomen shows pneumoperitoneum with free fluid, but no obvious site of perforation is identified. Serum lactate is 4.8 mmol/L. At laparotomy, two small jejunal perforations are found with minimal surrounding inflammation. What is the most likely underlying cause?
A. Perforated peptic ulcer
B. Mesenteric ischaemia
C. Ischaemic colitis with perforation
D. NSAIDs-induced enteropathy with perforation
E. Spontaneous intestinal perforation secondary to immunosuppression (Correct Answer)
Explanation: ***Spontaneous intestinal perforation secondary to immunosuppression***- Chronic **corticosteroid therapy** (at doses >10mg) combined with **methotrexate** significantly increases the risk of **spontaneous bowel perforation** by impairing the normal healing of microscopic defects.- The laparotomy finding of **minimal surrounding inflammation** is a classic hallmark of generalized **immunosuppression**, where the patient's immune system is unable to mount a normal inflammatory response.*Perforated peptic ulcer*- Typically originates in the **stomach or duodenum**, whereas the intraoperative findings in this patient specifically localized to the **jejunum**.- Usually presents with a history of dyspepsia and is less likely to present with multiple small bowel perforations simultaneously.*Mesenteric ischaemia*- Usually results in **segmental bowel necrosis** or extensive gangrene rather than isolated, discrete small bowel perforations.- Patients often present with **pain out of proportion** to clinical findings and risk factors like **atrial fibrillation** or generalized atherosclerosis.*Ischaemic colitis with perforation*- Characteristically involves the **colon** (large bowel), particularly at watershed areas like the **splenic flexure**, rather than the jejunum.- Symptoms generally include **bloody diarrhea** and lower abdominal pain rather than isolated small bowel sepsis.*NSAIDs-induced enteropathy with perforation*- Although **NSAIDs** can cause small bowel ulcers and "diaphragm-like" strictures leading to perforation, there is no history of NSAID use provided in this clinical vignette.- The presence of multiple immunosuppressants (steroids and methotrexate) makes **spontaneous perforation** due to immune suppression a more direct and likely causative factor.
