Gastrointestinal Pathology Practice Questions

Q: Which part of the gastrointestinal tract is most commonly affected by Crohn's disease?

Ileum. **Explanation:** Crohn’s disease is a chronic, transmural inflammatory bowel disease that can affect any part of the gastrointestinal tract from the mouth to the anus. However, it has a strong predilection for specific sites. **Why Ileum is Correct:** The **terminal ileum** is the most common site of involvement, affected in approximately 70–80% of patients. When the disease is confined to the small intestine, it is termed regional enteritis. The most frequent clinical presentation is **ileocolic involvement** (40–50%), where both the terminal ileum and the proximal ascending colon are affected. **Why Other Options are Incorrect:** * **Rectum:** Unlike Ulcerative Colitis, which always involves the rectum and spreads proximally, Crohn’s disease typically **spares the rectum** (rectal sparing is a diagnostic clue). * **Duodenum & Stomach:** Gastroduodenal Crohn’s is relatively rare, occurring in fewer than 5% of cases. It usually presents with symptoms mimicking peptic ulcer disease or gastric outlet obstruction. **High-Yield Clinical Pearls for NEET-PG:** * **Skip Lesions:** Crohn’s is characterized by discontinuous areas of inflammation with normal intervening mucosa. * **Transmural Inflammation:** Leads to complications like **fistulas, strictures, and "string sign of Kantor"** on barium studies. * **Cobblestone Appearance:** Result of deep longitudinal ulcers intersecting with edematous mucosa. * **Histology:** Non-caseating granulomas are pathognomonic (seen in ~50% of biopsies). * **Creeping Fat:** Mesenteric fat wraps around the bowel wall, a classic surgical finding in Crohn's.

Q: All of the following polyposis syndromes are associated with a high risk of malignancy except?

Juvenile polyposis. **Explanation:** The core concept in evaluating polyposis syndromes is distinguishing between **adenomatous polyps** (neoplastic) and **hamartomatous polyps** (non-neoplastic). **Why Juvenile Polyposis is the correct answer:** Juvenile polyposis syndrome (JPS) is characterized by multiple **hamartomatous polyps**. While there is a cumulative lifetime risk of colorectal cancer (approximately 40-50%) due to the potential for adenomatous transformation over time, it is considered to have a significantly lower and less "inevitable" malignant potential compared to the classical adenomatous syndromes. In the context of this competitive question, it is the "least" malignant option. **Analysis of Incorrect Options:** * **Familial Adenomatous Polyposis (FAP):** Caused by a mutation in the *APC* gene. It carries a **100% risk** of colorectal cancer by age 40 if a prophylactic proctocolectomy is not performed. * **Gardner’s Syndrome:** A variant of FAP. It includes colonic polyposis plus extra-colonic manifestations (osteomas, desmoid tumors, sebaceous cysts). It carries the same **100% malignancy risk** as FAP. * **Turcot’s Syndrome:** Another FAP variant (or associated with HNPCC) characterized by colonic polyposis associated with **CNS tumors** (Medulloblastoma or Glioma). It also carries a very high risk of malignancy. **High-Yield Clinical Pearls for NEET-PG:** * **FAP:** Thousands of polyps; "carpet-like" appearance; *APC* gene on Chromosome 5q21. * **Peutz-Jeghers Syndrome:** Hamartomatous polyps + perioral pigmentation; associated with *STK11* mutation. * **Most common site for Juvenile Polyps:** Rectum (often presents as painless rectal bleeding in children). * **Mnemonic for Gardner’s:** **SOD** (Sebaceous cysts, Osteomas, Desmoid tumors).

Q: Which of the following is the primary pathophysiological defect in achalasia cardia?

Absence of Auerbach's plexus nerves. **Explanation:** **Achalasia Cardia** is a primary esophageal motility disorder characterized by the failure of the Lower Esophageal Sphincter (LES) to relax and the absence of peristalsis in the distal esophagus [1]. **1. Why Option A is Correct:** The primary defect is the **degeneration and loss of inhibitory postganglionic neurons** in the **Auerbach’s (Myenteric) plexus**, located between the longitudinal and circular muscle layers [1]. Specifically, there is a loss of neurons that release **Nitric Oxide (NO) and Vasoactive Intestinal Peptide (VIP)**, which are essential for LES relaxation [1]. This leads to an unopposed excitatory stimulus (cholinergic), resulting in a hypertensive, non-relaxing LES. **2. Why Other Options are Incorrect:** * **Option B:** The smooth muscle of the LES is anatomically present; however, its physiological function is impaired due to the lack of inhibitory innervation. * **Option C:** Achalasia involves the *loss* or *absence* of ganglion cells, not hypertrophy [1]. Hypertrophy of nerves is more characteristic of conditions like Hirschsprung’s disease (proximal to the aganglionic segment) or certain neuromas, but not the primary defect in achalasia. **3. Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** Esophageal Manometry (shows incomplete LES relaxation and aperistalsis). * **Barium Swallow Finding:** "Bird’s beak" or "Rat-tail" appearance. * **Triad of Achalasia:** Incomplete LES relaxation, increased LES tone, and aperistalsis of the esophagus [1]. * **Chagas Disease:** Caused by *Trypanosoma cruzi*, it is a common secondary cause of achalasia due to the destruction of the myenteric plexus. * **Treatment of Choice:** Laparoscopic Heller’s Myotomy (often with Dor/Toupet fundoplication) or POEM (Peroral Endoscopic Myotomy).

Q: Which of the following statements is false regarding pernicious anemia?

Serum gastrin level is decreased. Pernicious anemia is an autoimmune condition characterized by the destruction of gastric parietal cells, leading to a profound deficiency of **Intrinsic Factor (IF)** and gastric acid (achlorhydria). [1, 2] **1. Why Option D is the correct (False) statement:** In pernicious anemia, the destruction of parietal cells leads to **achlorhydria** (absence of hydrochloric acid). Under normal physiological conditions, gastric acid provides negative feedback to G-cells in the antrum. In the absence of acid, this feedback loop is lost, resulting in **hypergastrinemia** (increased serum gastrin levels) as the body attempts to stimulate non-existent parietal cells. [1] Therefore, saying gastrin is decreased is incorrect. **2. Analysis of incorrect (True) options:** * **Option A:** True. The hallmark of the disease is a severe lack of IF, which is essential for Vitamin B12 absorption in the terminal ileum. * **Option B:** True. It is an autoimmune Type IV hypersensitivity reaction involving autoantibodies against parietal cells and intrinsic factor. [2] * **Option C:** True. Chronic inflammation leads to **Type A (Autoimmune) Gastritis**, causing diffuse atrophy of the acid-secreting mucosa in the **body and fundus**, while the antrum is typically spared. [2] **Clinical Pearls for NEET-PG:** * **Diagnostic Markers:** Anti-parietal cell antibodies (sensitive) and Anti-intrinsic factor antibodies (highly specific). * **Peripheral Smear:** Hypersegmented neutrophils and macro-ovalocytes. * **Schilling Test:** Historically used to diagnose B12 malabsorption (now largely replaced by antibody testing). * **Malignancy Risk:** Patients have a 3x increased risk of **Gastric Adenocarcinoma** and **Gastric Carcinoid tumors** due to chronic hypergastrinemia.

Question 1

Which part of the gastrointestinal tract is most commonly affected by Crohn's disease?

Accepted Answer

Ileum

Answer

Rectum

Answer

Duodenum

Answer

Stomach

Question 2

Epulis is classified as:

Accepted Answer

Malignant

Answer

Benign

Answer

Reactive process

Answer

Precancerous

Question 3

Which of the following is FALSE about Barrett's esophagus?

Accepted Answer

Barrett's ulcer occurs just above the squamocolumnar junction.

Answer

In short-segment Barrett's, there is less than 3 cm of columnar epithelium.

Answer

If a peptic stricture occurs in Barrett's esophagus, it always occurs at the new squamocolumnar junction.

Answer

It is a premalignant condition.

Question 4

All of the following polyposis syndromes are associated with a high risk of malignancy except?

Accepted Answer

Juvenile polyposis

Answer

Familial adenomatous polyposis

Answer

Gardner's syndrome

Answer

Turcot's syndrome

Question 5

What is true about intestinal lymphoma?

Accepted Answer

It is involved in non-Hodgkin's lymphoma.

Answer

It is made up of predominantly T cells.

Answer

It is C-kit positive.

Answer

It is most common at the ileocecal junction.

Question 6

A 45-year-old man presents with a painless mass in the neck. A 4-cm firm, movable tumor is identified at the angle of the left jaw. A biopsy of the tumor reveals myoepithelial cells intermingled with myxoid, mucoid, and callaginous areas. The tumor is removed surgically. What is the most likely prognosis?

Accepted Answer

Local recurrence

Answer

Contralateral spread

Answer

Invasion of bone

Answer

Malignant transformation

Question 7

Which of the following is the primary pathophysiological defect in achalasia cardia?

Accepted Answer

Absence of Auerbach's plexus nerves

Answer

Absence of smooth muscles in the lower esophageal sphincter

Answer

Hypertrophy of nerves in the esophageal wall

Answer

None of the above

Question 8

Which of the following statements is false regarding pernicious anemia?

Accepted Answer

Serum gastrin level is decreased

Answer

Severe lack of intrinsic factor

Answer

Autoimmune disorder against parietal cells of the stomach

Answer

Atrophy of all layers of the body and fundus

Question 9

A 70-year-old male with a 50-year history of chewing tobacco presents with a six-month history of a large, fungating, soft papillary lesion in the oral cavity. The lesion has penetrated into the mandible. Lymph nodes are not palpable. Two biopsies from the lesion show benign-appearing papillomatosis with hyperkeratosis and acanthosis infiltrating the subjacent tissues. What is the most likely diagnosis?

Accepted Answer

Verrucous carcinoma

Answer

Squamous cell papilloma

Answer

Squamous cell carcinoma

Answer

Malignant mixed tumour

Question 10

The pathological appearance in pseudomembranous colitis consists of?

Accepted Answer

Small ulceration with slough

Answer

Necrosis and gangrene

Answer

Serositis covered by membrane

Answer

Excessive ulceration in serosa

Gastrointestinal Pathology — MCQs

Gastrointestinal Pathology — MCQs

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