Colorectal Surgery Practice Questions

Q: A homosexual man complains of painful defecation and mass protruding from the anal canal. Biopsy reveals squamous cell carcinoma of anus. Correct management for this patient is

Combined chemoradiation. ***Combined chemoradiation***- **Combined chemoradiation (Nigro protocol)** is the standard of care and preferred, organ-preserving primary treatment for most stages of squamous cell carcinoma of the anus.- This curative regimen typically involves sequential or concurrent use of **5-Fluorouracil**, **Mitomycin C** (or Cisplatin), and focused external beam radiation therapy, resulting in high rates of complete remission.*Chemotherapy*- Chemotherapy alone is insufficient as a curative primary modality for localized anal carcinoma and is inferior to combined treatment.- Systemic chemotherapy is primarily reserved for the management of **metastatic** disease or palliation in advanced, unresectable cases.*Abdominoperineal repair*- **Abdominoperineal resection (APR)**, which creates a permanent colostomy, is primarily reserved as a highly morbid **salvage operation** for locoregional failure following initial chemoradiation.- Primary APR is rarely performed because combined chemoradiation offers similar long-term survival rates with sphincter preservation.*Wide local excision*- **Wide local excision (WLE)** is only appropriate for very small (T1, <2cm), well-differentiated tumors located at the anal margin (perianal skin), which are much less common.- A bulky, protruding mass usually indicates a deeper primary tumor or involvement of the anal canal, requiring definitive **chemoradiation** rather than surgery.

Q: A man came with complaints of recurrent discharge and pain due to lesions around the anus for 3 years. A diagnosis of fistula-in-ano is made. What is the gold standard investigation for this condition?

MRI. ***MRI*** - **Gold standard investigation** for fistula-in-ano for preoperative assessment - Provides **superior soft tissue contrast** and multiplanar imaging capabilities - Accurately delineates the **fistula tract, internal and external openings** - Detects **secondary tracts, horseshoe extensions, and abscesses** - Helps in **Parks classification** (intersphincteric, trans-sphincteric, suprasphincteric, extrasphincteric) - Essential for **surgical planning** and predicting recurrence risk - MRI with fat suppression sequences (T2-weighted) provides best visualization *Fistulogram* - Outdated investigation with **limited accuracy** (40-50%) - Cannot adequately assess sphincter involvement or secondary tracts - Invasive and uncomfortable for the patient - Risk of extravasation and infection *USG (Endoanal/Transperineal Ultrasound)* - Useful adjunct but **not gold standard** - Operator-dependent with limited field of view - Difficulty visualizing high or complex fistulas - Less accurate for secondary extensions *CECT* - Not routinely used for fistula-in-ano assessment - **Inferior soft tissue resolution** compared to MRI - Radiation exposure - Limited differentiation of sphincter anatomy

Q: A 65-year-old patient undergoes colonoscopy for altered bowel habits. A 6 cm colonic mass is biopsied and histopathology shows adenocarcinoma confined to the mucosa with no lymph node or distant metastasis. What is the most appropriate TNM stage of this tumor?

Stage 0. ### **Explanation** The correct answer is **Stage 0**. #### **1. Why Stage 0 is Correct** In the TNM staging of colorectal cancer, the depth of invasion is the primary determinant of the 'T' stage. * **Carcinoma in situ (Tis):** This is defined as cancer cells confined to the **mucosa** (epithelium or lamina propria) without extension through the **muscularis mucosae** into the submucosa. * Because the colonic mucosa lacks lymphatic channels (which begin in the submucosa), tumors confined to the mucosa have essentially **zero risk of regional lymph node metastasis**. * According to the AJCC staging system, **Tis N0 M0** is classified as **Stage 0**. #### **2. Why Other Options are Incorrect** * **Stage I (T1-T2 N0 M0):** Requires invasion into the **submucosa** (T1) or the **muscularis propria** (T2). * **Stage II (T3-T4 N0 M0):** Occurs when the tumor invades through the muscularis propria into the subserosa (T3) or perforates the visceral peritoneum/invades adjacent organs (T4), but without nodal involvement. * **Stage III (Any T, N1-N2 M0):** This stage is defined by the presence of **regional lymph node metastasis**, regardless of the depth of T invasion. #### **3. High-Yield Clinical Pearls for INI-CET** * **The "No Lymphatics" Rule:** Unlike the stomach or esophagus, the colonic lamina propria has no lymphatic vessels. Therefore, "intramucosal carcinoma" in the colon is biologically equivalent to carcinoma in situ. * **Management:** Most Stage 0 lesions can be managed via **endoscopic mucosal resection (EMR)** or polypectomy rather than formal colectomy, provided margins are clear. * **TNM Staging Quick Recall:** * **T1:** Submucosa * **T2:** Muscularis propria * **T3:** Subserosa/Pericolonic fat * **T4:** Perforation of serosa or invasion of other organs.

Q: Identify the fistula according to Park's classification?

Intersphincteric. ***Intersphincteric*** - This type of fistula tract is confined entirely to the space **between the internal and external anal sphincters**, as clearly depicted in the image. - It represents the **most common** variety of anal fistula, accounting for about 70% of cases in Park's classification. *Supra-sphincteric* - A supra-sphincteric fistula passes through the intersphincteric space, hooks **above the puborectalis muscle**, and then descends through the ischiorectal fossa. - The illustrated tract does not traverse cephalad to the **external anal sphincter** or the puborectalis muscle. *Extra-sphincteric* - This rare type runs **outside both the internal and external anal sphincters** and often penetrates the levator ani muscle to connect the rectum to the perianal skin. - The tract shown is contained **within the muscle planes** of the anal canal, ruling out an extra-sphincteric course. *Trans-sphincteric high* - High trans-sphincteric fistulas pass **through the upper portion of the external anal sphincter** into the ischiorectal fossa, making them more complex to manage with sphincter-sparing techniques compared to low trans-sphincteric fistulas. - The depicted track runs strictly **between** the internal and external layers without crossing the external sphincter.

Q: Identify the instrument in the image:

St Mark's perineal retractor. ***St Mark's perineal retractor*** - This image displays the classic configuration of a **St. Mark's perineal retractor**, which is a self-retaining retractor used to expose the perineal area. - It features two articulating blades with multiple prongs, often shaped distinctly (as seen with the upper blade resembling an elephant's head with teeth), and a **ratchet mechanism** to hold the blades open. *Joll retractor* - A **Joll retractor** is typically used in thyroid surgery and consists of a single blade or a pair of blades, which are more delicate and shaped differently, not self-retaining like the one shown. - It is designed to provide retraction in a more confined area and does not have the complex self-retaining mechanism or multiple broad prongs. *Deaver retractor* - A **Deaver retractor** is a handheld retractor with a distinct S-shaped blade, used primarily for deep abdominal or thoracic retraction. - It does not have a self-retaining mechanism or the multiple prongs characteristic of the instrument in the image. *Goligher retractor* - A **Goligher retractor** is a specific type of self-retaining retractor, but its design differs significantly from the one pictured; it typically has multiple interchangeable blades and a different frame structure. - While it is also self-retaining, it is mainly used for deep abdominal or pelvic surgery and has a more robust frame compared to the depicted perineal retractor.

Q: Identify the instrument in the image:

Goligher retractor. ***Goligher retractor*** - This image displays a **Goligher self-retaining retractor**, characterized by multiple blades that can be adjusted to provide broad and deep retraction. - It is often used in **abdominal and pelvic surgeries**, particularly in colorectal procedures, for optimal exposure of deep structures. *Langenbeck retractor* - A Langenbeck retractor is a **small, L-shaped handheld retractor** with a flat, right-angled blade. - It is typically used for **retracting small incisions** or superficial tissues, not large cavities. *Joll retractor* - A Joll retractor is a **self-retaining retractor** primarily used in **thyroid surgery**. - Its design is specific for neck anatomy, featuring two adjustable blades attached to a central bar. *Deaver retractor* - A Deaver retractor is a **large, flat, curved handheld retractor**, resembling a question mark. - It is commonly used for **deep abdominal retraction** to hold back organs, but it is not self-retaining nor does it have multiple interlocking blades like the one pictured.

Q: Identify the surgical instrument shown in the image:

Anoscope. ***Anoscope*** - The image displays a short, rigid instrument with a removable obturator, designed for visualizing the **anal canal**. - Its typical use involves the examination of the **anus and rectum** for conditions such as hemorrhoids or anal fissures. *Proctoscope* - A proctoscope is generally a **longer and wider, rigid scope** used to visualize the rectum and distal sigmoid colon. - While an anoscope can sometimes be referred to as a short proctoscope, a typical proctoscope is designed for a more extensive view beyond the anal canal. *Sigmoidoscope* - A sigmoidoscope is a **longer, flexible or rigid instrument** used to examine the entire sigmoid colon, which is much further than the instrument shown can reach. - It allows for the detection of polyps or abnormalities in the **distal large intestine**. *Colonoscope* - A colonoscope is a much **longer and flexible instrument** designed to visualize the entire large intestine (colon) and often the terminal ileum. - It is used for comprehensive screening and diagnostic procedures like **colonoscopies**.

Q: The diagnosis of this patient with left-sided abdominal pain and tyre-like feel of abdomen is?

Sigmoid volvulus. ***Sigmoid volvulus*** - The image shows massively dilated loops of bowel forming an **omega loop** or "inverted U" appearance, characteristic of **sigmoid volvulus**. The "tyre-like feel" upon palpation is consistent with a distended, gas-filled colon. - Clinical presentation with **left-sided abdominal pain** and signs of **large bowel obstruction** further supports this diagnosis, especially with the characteristic radiological findings. *Diverticulitis* - Diverticulitis typically presents with **left lower quadrant pain**, fever, and localized tenderness, but not usually with the massive abdominal distension and "tyre-like" feel seen in major bowel obstruction. - Radiological findings in diverticulitis often include **pericolic fat stranding**, wall thickening, and diverticula, rather than dramatically dilated bowel loops. *Paralytic ileus* - **Paralytic ileus** involves generalized bowel distension due to decreased peristalsis, often affecting both small and large bowel, rather than the localized, massive dilation of a single segment as seen here. - While there is distension, the distinct "inverted U" or omega loop configuration pointing to a specific segment of the bowel causing obstruction is not a feature of paralytic ileus. *Intussusception* - **Intussusception** is more common in children and typically presents with intermittent abdominal pain, vomiting, and "current jelly" stools, not primarily with palpable mass or a "tyre-like" feel on the *sigmoid* colon as described. - Radiologically, intussusception might show a "target sign" on ultrasound or an absence of gas distal to the obstruction, not the massively dilated sigmoid loop seen in the radiograph.

Q: What is the preferred treatment for the shown lesion?

5-FU + Mitomycin C + Radiotherapy. ***5-FU + Mitomycin C + Radiotherapy*** - The image shows an **exophytic lesion near the anus**, which is highly suggestive of **anal squamous cell carcinoma (SCC)**. The preferred treatment for anal SCC is **chemoradiation**. - The regimen of 5-fluorouracil (5-FU) and Mitomycin C, combined with **radiotherapy**, is the **Nigro protocol**, which is the current standard of care for anal cancer, aiming for organ preservation and cure. - This non-surgical approach has replaced radical surgery for most anal cancers, with excellent cure rates and quality of life preservation. *5-fluorouracil + Mitomycin C* - While these chemotherapy agents are part of the standard treatment for anal SCC, they are typically used in conjunction with **radiotherapy** to achieve optimal outcomes. - Chemotherapy alone without radiation is generally insufficient for curative intent in anal SCC. *Mitomycin C + Cisplatin* - This combination includes two potent chemotherapy drugs, but it is not the standard protocol for anal SCC. - While cisplatin can be used in some anal cancer regimens (particularly as salvage therapy), the combination with Mitomycin C in the absence of 5-FU and radiotherapy is not the primary choice. *Abdominoperineal resection (APR)* - APR was historically the standard treatment for anal cancer but has been largely replaced by chemoradiation (Nigro protocol). - Surgery is now reserved for salvage therapy in cases of persistent or recurrent disease after chemoradiation failure. - The shift to chemoradiation has significantly improved quality of life by preserving the anal sphincter and avoiding permanent colostomy.

Q: A 29-year-old male who is a doctor by profession, gives a history of prolonged sitting in his OPD hours and presents with discharge and pain. Clinical presentation of the patient is given in the image. What is the most likely diagnosis?

Pilonidal sinus. ***Pilonidal sinus*** - The image shows a **pit** or **opening** in the **natal cleft** with surrounding inflammation and discharge, which is characteristic of a pilonidal sinus. - The history of **prolonged sitting** (*a doctor by profession has prolonged sitting hours in OPD*) and the patient's age (29-year-old male) are common risk factors for pilonidal disease. *Anal fissure* - An anal fissure is a **tear** in the **lining of the anal canal**, typically causing severe pain during and after defecation, and often bright red rectal bleeding. - The lesion in the image is located in the **natal cleft**, not within the anal canal, and presents as a sinus with discharge rather than a linear tear. *Anal fistula* - An anal fistula is an abnormal tunnel connecting the **anal canal to the skin outside** the anus, usually presenting as a small opening with intermittent or persistent discharge of pus or blood. - While it involves discharge, an **anal fistula** typically has an external opening closer to the anus, and the image clearly shows the lesion in the **sacrococcygeal region**, consistent with a pilonidal sinus. *Sentinel pile* - A sentinel pile is a **skin tag** that often accompanies a **chronic anal fissure**, located at the external edge of the fissure. - It is essentially excess skin and usually does not present with **discharge** or the characteristic **sinus tract** seen in the image.

Question 1

A homosexual man complains of painful defecation and mass protruding from the anal canal. Biopsy reveals squamous cell carcinoma of anus. Correct management for this patient is

Accepted Answer

Combined chemoradiation

Answer

Wide local excision

Answer

Chemotherapy

Answer

Abdominoperineal repair

Question 2

A man came with complaints of recurrent discharge and pain due to lesions around the anus for 3 years. A diagnosis of fistula-in-ano is made. What is the gold standard investigation for this condition?

Accepted Answer

MRI

Answer

Fistulogram

Answer

USG

Answer

CECT

Question 3

A 65-year-old patient undergoes colonoscopy for altered bowel habits. A 6 cm colonic mass is biopsied and histopathology shows adenocarcinoma confined to the mucosa with no lymph node or distant metastasis. What is the most appropriate TNM stage of this tumor?

Accepted Answer

Stage 0

Answer

Stage II

Answer

Stage III

Answer

Stage I

Question 4

Identify the fistula according to Park's classification?

Accepted Answer

Intersphincteric

Answer

Extra-sphincteric

Answer

Trans-sphincteric high

Answer

Supra-sphincteric

Question 5

Identify the instrument in the image:

Accepted Answer

St Mark's perineal retractor

Answer

Joll retractor

Answer

Deaver retractor

Answer

Goligher retractor

Question 6

Identify the instrument in the image:

Accepted Answer

Goligher retractor

Answer

Langenbeck retractor

Answer

Joll retractor

Answer

Deaver retractor

Question 7

Identify the surgical instrument shown in the image:

Accepted Answer

Anoscope

Answer

Proctoscope

Answer

Sigmoidoscope

Answer

Colonoscope

Question 8

The diagnosis of this patient with left-sided abdominal pain and tyre-like feel of abdomen is?

Accepted Answer

Sigmoid volvulus

Answer

Diverticulitis

Answer

Paralytic ileus

Answer

Intussusception

Question 9

What is the preferred treatment for the shown lesion?

Accepted Answer

5-FU + Mitomycin C + Radiotherapy

Answer

5-fluorouracil + Mitomycin C

Answer

Mitomycin C + Cisplatin

Answer

Abdominoperineal resection (APR)

Question 10

A 29-year-old male who is a doctor by profession, gives a history of prolonged sitting in his OPD hours and presents with discharge and pain. Clinical presentation of the patient is given in the image. What is the most likely diagnosis?

Accepted Answer

Pilonidal sinus

Answer

Anal fissure

Answer

Anal fistula

Answer

Sentinel pile

Colorectal Surgery — MCQs

Colorectal Surgery — MCQs

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