You’re cruising through a GI question set, and then it hits you: “Which diagnosis is most likely?” The stem feels straightforward… until the answer explanations reveal that every single choice is a trap designed to test pattern recognition, risk factors, and pathology. This post walks through a classic gastric cancer vignette the way you should on test day: lock in the correct answer, then rapidly eliminate distractors using high-yield discriminators.
Tag: GI > Esophageal & Gastric Disorders
The Clinical Vignette (Q-bank style)
A 62-year-old man presents with 3 months of progressive fatigue, early satiety, and unintentional weight loss. He also notes intermittent epigastric discomfort and “dark stools.” He has a 40-pack-year smoking history. He emigrated from Korea 20 years ago. Vitals are normal. Exam shows mild conjunctival pallor and mild epigastric tenderness without rebound. Labs show hemoglobin 9.8 g/dL with MCV 72 fL. Fecal occult blood test is positive. Upper endoscopy reveals an ulcerated mass along the lesser curvature of the stomach; biopsy shows irregular glandular structures infiltrating the gastric wall.
Question: What is the most likely diagnosis?
Correct Answer: Gastric adenocarcinoma (intestinal type)
Why it’s correct
This stem stacks multiple classic clues:
- Constitutional symptoms + early satiety → suggests a space-occupying gastric process
- Occult GI bleeding + microcytic anemia ( MCV) → chronic blood loss
- Risk factors:
- East Asian origin (higher incidence regions: Japan, Korea, China, parts of Latin America/Eastern Europe)
- Smoking
- Often associated with H. pylori (even if not stated)
- Endoscopic ulcerated mass (especially along the lesser curvature/antrum is common)
- Histology: irregular glands infiltrating → adenocarcinoma, intestinal type
High-yield pathology and associations (Step-ready)
Gastric adenocarcinoma: two big patterns
| Feature | Intestinal type | Diffuse type |
|---|---|---|
| Common location | Antrum/lesser curvature | Anywhere (often body) |
| Gross | Exophytic/ulcerated mass | Diffuse thickened “leather bottle” stomach (linitis plastica) |
| Histology | Gland-forming malignant cells | Signet ring cells, no glands |
| Key risks | H. pylori, chronic gastritis, intestinal metaplasia, nitrosamines/smoked foods | CDH1 (E-cadherin) mutation, can be familial |
| Mechanism vibe | “Inflammation → metaplasia → dysplasia → cancer” | “Loss of cohesion → infiltration” |
Testable facts:
- H. pylori increases risk of:
- Gastric adenocarcinoma (via chronic gastritis → intestinal metaplasia)
- MALT lymphoma (via lymphoid aggregates in mucosa)
- “Alarm features” in dyspepsia (think malignancy until proven otherwise):
- Weight loss, anemia, GI bleeding, progressive dysphagia, persistent vomiting, palpable mass
Why the Other Answer Choices Are Wrong (and what they were testing)
Below are classic distractors in this exact question family.
Distractor 1: Gastric lymphoma (MALT lymphoma)
Why it tempts you: H. pylori is a shared theme with gastric cancer, and both can present with vague epigastric symptoms.
Why it’s wrong here:
- The biopsy in the stem shows irregular glands → epithelial malignancy (adenocarcinoma), not lymphoma.
- MALT lymphoma histology would suggest:
- Dense lymphoid infiltrates
- Lymphoepithelial lesions (lymphocytes invading gastric glands)
High-yield clue:
MALT lymphoma often improves with H. pylori eradication (e.g., PPI + amoxicillin + clarithromycin or metronidazole depending on regimen).
Distractor 2: Peptic ulcer disease (benign gastric ulcer)
Why it tempts you: Epigastric discomfort + melena + anemia screams ulcer.
Why it’s wrong here:
- Unintentional weight loss + early satiety are red flags for malignancy.
- Endoscopy described an ulcerated mass, not a clean-based benign ulcer.
- Biopsy shows infiltrating malignant glands.
High-yield discrimination:
Benign ulcers typically have smooth, regular margins; malignant ulcers/masses can have heaped-up, irregular borders. When in doubt: biopsy.
Distractor 3: Gastric gastrointestinal stromal tumor (GIST)
Why it tempts you: GIST is a stomach tumor and can bleed.
Why it’s wrong here:
- GIST arises from interstitial cells of Cajal (mesenchymal), not glandular epithelium.
- Histology is typically spindle cells, not irregular glands.
High-yield facts:
- Markers: c-KIT (CD117) positive
- Can be associated with activating KIT mutations
- Treatment often includes imatinib (a tyrosine kinase inhibitor)
Distractor 4: Zollinger–Ellison syndrome (gastrinoma)
Why it tempts you: Ulcers + pain can trigger the “ZE syndrome” reflex.
Why it’s wrong here:
- The stem emphasizes mass in the stomach with infiltrating glands, not recurrent/refractory duodenal ulcers.
- ZE classically causes:
- Multiple duodenal ulcers
- Diarrhea/steatorrhea (acid inactivates pancreatic enzymes)
- Very high gastrin, low gastric pH
High-yield association:
Gastrinoma is linked to MEN1 (pituitary, parathyroid, pancreatic endocrine tumors).
Distractor 5: Esophageal adenocarcinoma (Barrett-related)
Why it tempts you: Weight loss + anemia + GI malignancy risk factors (smoking).
Why it’s wrong here:
- Lesion is in the stomach (lesser curvature), not distal esophagus/GE junction.
- The stem doesn’t describe chronic GERD, dysphagia, or Barrett changes.
High-yield facts:
- Esophageal adenocarcinoma:
- Risk: Barrett esophagus from chronic GERD
- Location: distal esophagus
- Esophageal squamous cell carcinoma:
- Risks: smoking, alcohol, very hot beverages, achalasia
- Location: mid esophagus
Distractor 6: Gastric diffuse-type adenocarcinoma (signet ring)
Why it tempts you: It’s still gastric adenocarcinoma—easy to pick the wrong subtype.
Why it’s wrong here:
- Stem says irregular glandular structures → intestinal type.
- Diffuse type shows signet ring cells and lacks gland formation.
High-yield associations:
- Diffuse type: CDH1 mutation (E-cadherin), linitis plastica
- Can metastasize to the ovary → Krukenberg tumor (bilateral mucin-producing signet ring metastases)
Quick “Board-Mode” Framework for Similar Questions
When you see gastric cancer, think:
- Symptoms: weight loss, early satiety, anemia/melena
- Risks: H. pylori, smoking, high-incidence regions, nitrosamines/smoked foods, chronic atrophic gastritis
- Diagnosis: endoscopy with biopsy (CT for staging)
When you see biopsy clues, map them fast:
- Glands → adenocarcinoma (intestinal type if gland-forming)
- Signet ring cells → diffuse gastric cancer
- Spindle cells + c-KIT → GIST
- Lymphoid infiltrates → MALT lymphoma
Takeaway: Every Answer Choice Is a Mini-Question
The stem tests whether you recognize gastric adenocarcinoma—but the answer choices test whether you can:
- tie symptoms to anatomy,
- use histology to identify tissue origin,
- and separate “H. pylori diseases” into adenocarcinoma vs MALT.
If you can explain why each distractor is wrong in one sentence, you’re doing Q-banks the way Step wants.