Gastrointestinal Pathology Practice Questions

Q: What is the most common type of cancer affecting the anus?

Squamous cell carcinoma. **Explanation:** The anal canal is lined by different types of epithelium depending on the anatomical level. The area below the pectinate (dentate) line is lined by **stratified squamous epithelium**, which continues as the perianal skin. Consequently, **Squamous Cell Carcinoma (SCC)** is the most common histological type of anal cancer, accounting for approximately 80–85% of cases. It is strongly associated with high-risk **Human Papillomavirus (HPV)** infection, particularly types 16 and 18. **Analysis of Options:** * **A. Squamous cell carcinoma (Correct):** As the anal canal distal to the transformation zone is squamous, this is the predominant malignancy. * **B. Basaloid carcinoma:** This is a histological variant of SCC that arises from the transitional (cloacogenic) zone. While characteristic of the anal canal, it is less common than pure SCC. * **C. Cuboidal cell carcinoma:** This is not a standard primary malignancy of the anus. The upper anal canal is columnar/glandular, leading to adenocarcinomas, not cuboidal cell carcinomas. * **D. Cloacogenic carcinoma:** This term refers to tumors arising from the transitional zone (the "cloacogenic" membrane remnant). Modern WHO classifications now categorize these as a subtype of squamous cell carcinoma rather than a distinct entity. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** HPV infection (most common), multiple sexual partners, receptive anal intercourse, and HIV infection. * **Precursor Lesion:** Anal Intraepithelial Neoplasia (AIN). * **Lymphatic Spread:** Above the pectinate line, drainage is to internal iliac nodes; below the line, it is to **superficial inguinal nodes** (frequently tested). * **Treatment:** Unlike rectal cancer (surgery), the primary treatment for anal SCC is the **Nigro Protocol** (Chemoradiotherapy).

Q: Which site is invariably involved in ulcerative colitis?

Rectum. **Explanation:** **Ulcerative Colitis (UC)** is a chronic inflammatory bowel disease characterized by continuous mucosal inflammation that starts in the distal colon and spreads proximally [1]. **Why Rectum is the Correct Answer:** The hallmark of Ulcerative Colitis is its **invariable involvement of the rectum** [1]. The disease process begins at the anal verge and extends proximally in a continuous, symmetrical fashion without "skip lesions." In approximately 95% of cases, the rectum is involved at the time of diagnosis. If the rectum is completely spared in an untreated patient, the diagnosis of Crohn’s disease should be strongly considered instead. **Analysis of Incorrect Options:** * **A & B (Sigmoid and Transverse Colon):** While these sites are frequently involved as the disease progresses proximally (proctosigmoiditis or extensive colitis), they are not involved in every single case. UC can be limited to the rectum alone (ulcerative proctitis) [1]. * **C (Ileum):** UC primarily affects the colon. The ileum is generally spared, except in cases of **"backwash ileitis,"** where the terminal ileum shows mild inflammation due to an incompetent ileocecal valve in patients with pancolitis [1]. **NEET-PG High-Yield Pearls:** * **Distribution:** Continuous involvement (No skip lesions) [1]. * **Depth:** Limited to **Mucosa and Submucosa** (unlike Crohn’s, which is transmural) [1]. * **Microscopy:** Crypt abscesses and crypt distortion are characteristic. * **Gross Feature:** **Pseudopolyps** (regenerating islands of mucosa) and "Lead-pipe" appearance on barium enema due to loss of haustrations. * **Smoking:** Paradoxically, smoking is protective in UC (but a risk factor for Crohn’s). * **Marker:** p-ANCA is frequently positive. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 367-368.

Question 1

What is the most common type of cancer affecting the anus?

Accepted Answer

Squamous cell carcinoma

Answer

Basaloid carcinoma

Answer

Cuboidal cell carcinoma

Answer

Cloacogenic carcinoma

Question 2

Diarrhea with acanthocytosis is seen in which of the following conditions?

Accepted Answer

Wolman's disease

Answer

Whipple's disease

Answer

Celiac sprue

Answer

Agammaglobulinemia

Question 3

What is the pathology in achalasia cardiae?

Accepted Answer

Degeneration of nerves

Answer

Muscular atrophy

Answer

Hypertrophy of nerves

Answer

Hypertrophy of muscles

Question 4

Which site is invariably involved in ulcerative colitis?

Accepted Answer

Rectum

Answer

Sigmoid colon

Answer

Transverse colon

Answer

Ileum

Question 5

A 25-year-old male presents with a history of chronic diarrhea. Pathological examination reveals cryptitis and crypt abscesses. What is the likely diagnosis?

Accepted Answer

Ulcerative colitis

Answer

Crohn's disease

Answer

Giardiasis

Answer

Microscopic colitis

Question 6

A 61-year-old man presents with 5 months of increasing fatigue, early satiety, and nausea, and vomited dark granular material yesterday. Endoscopy reveals a large ulcerated mass in the gastric fundus. Biopsies show a mass composed of spindle cells positive for c-Kit by immunohistochemistry with frequent mitoses. A 10-cm circumscribed mass is resected from the gastric wall. Which of the following therapies is most likely to be a useful adjunct in the treatment of his disease?

Accepted Answer

Imatinib

Answer

Amoxicillin

Answer

Azathioprine

Answer

Cyclophosphamide

Question 7

Which of the following conditions is characterized by a cobblestone appearance of the oral mucosa?

Accepted Answer

Crohn disease

Answer

Ulcerative colitis

Answer

Whipple disease

Answer

All of the above

Question 8

Which conditions are characterized by the presence of macrophages, granulomas, and erythrophagocytosis?

Accepted Answer

Regional ileitis

Answer

Ulcerative colitis

Answer

Necrotising enterocolitis

Answer

Typhoid

Question 9

A jejunal biopsy is diagnostic in which of the following conditions?

Accepted Answer

Beta-lipoproteinemia

Answer

Giardiasis

Answer

Tropical sprue

Answer

Celiac sprue

Question 10

Which of the following statements about Familial Polyposis Coli is false?

Accepted Answer

There are hamartomatous polyps, and at least 80 polyps are required for diagnosis.

Answer

It is an autosomal dominant condition leading to multiple polyp formation in the colon.

Answer

There is a 100 percent risk of carcinoma in the polyps.

Answer

Gardner syndrome is colonic polyposis associated with osteomas, fibromatosis, and cutaneous cysts.

Gastrointestinal Pathology — MCQs

Gastrointestinal Pathology — MCQs

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