PA23.1-9 | Gastrointestinal Tract — Graded Quiz

A 55-year-old gutka-chewer from rural Maharashtra presents with progressive inability to open his mouth beyond 1 cm (interincisal distance). Examination reveals fibrous bands in the buccal mucosa and blanching of the mucosa bilaterally. A punch biopsy shows juxta-epithelial hyalinisation of the lamina propria with moderate epithelial dysplasia. He asks about his cancer risk. Which statement MOST accurately describes the malignant potential of his current lesion relative to erythroplakia?

A 48-year-old woman with a 15-year history of gastro-oesophageal reflux disease presents for surveillance endoscopy. Biopsies from the lower oesophagus show high-grade dysplasia in a background of specialised intestinal metaplasia. She undergoes oesophagectomy. The surgical resection specimen shows a 3 cm polypoid mass at the gastro-oesophageal junction with pushing margins. Histology confirms moderately differentiated adenocarcinoma. Which gross morphological pattern does this specimen represent, and where does this type of oesophageal carcinoma characteristically arise?

A 70-year-old man on long-term NSAIDs for arthritis is admitted with sudden-onset severe epigastric pain radiating to the back. His abdomen is rigid on palpation. An erect chest X-ray shows free air under the right hemidiaphragm. He has a known 1.5 cm posterior duodenal ulcer on recent endoscopy. Which complication has occurred, and which artery is at risk if this ulcer erodes posteriorly rather than perforating anteriorly?

A surgeon resects a total gastrectomy specimen for diffuse-type gastric carcinoma. The gastric wall is markedly thickened and rigid throughout, with loss of rugal folds; the mucosa shows no discrete ulcer or polypoid mass. Histology shows poorly cohesive signet-ring cells infiltrating the wall individually, without gland formation. At the same operation, a firm ovarian mass is found bilaterally and resected; histology shows signet-ring cell adenocarcinoma within the ovarian stroma. What is the term for the gastric gross pattern and the ovarian finding, respectively?

A 35-year-old farmer from Bihar presents with a 6-month history of intermittent colicky right lower quadrant pain, fever, and a 5 kg weight loss. Colonoscopy reveals a firm, mass-like thickening of the ileocaecal region with overlying mucosal ulceration. A CT scan confirms wall thickening with enlarged pericaecal lymph nodes showing central hypodensity. Biopsies show confluent caseating granulomas in all layers of the bowel wall with Langhans giant cells. Which morphological form of intestinal tuberculosis does this most likely represent, and what is its pathognomonic gross ulcer characteristic on the luminal surface?

A 60-year-old man with a 20-year history of ulcerative colitis involving the entire colon undergoes surveillance colonoscopy. He has previously been maintained on mesalazine with moderate control. A biopsy from the transverse colon shows high-grade dysplasia. He asks about his surgical risk. He is also found to have elevated ALP and a bead-like beading appearance on MRCP of the biliary tree. Which single extraintestinal complication is he most likely to have, and what is its pathological basis?

A 28-year-old man from Punjab presents with chronic diarrhoea, steatorrhoea, and weight loss for 18 months. He consumes wheat chapatis as his staple food. Anti-tTG IgA is borderline elevated. A D-xylose absorption test returns a low urinary xylose excretion at 4.5 g/5h (normal >5 g/5h). Duodenal biopsies show subtotal villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes (>30 IEL per 100 enterocytes). A serum Schilling test for Vitamin B12 absorption is performed; the corrected result remains abnormal even when intrinsic factor is added. Which interpretation of the Schilling test result and its anatomical implication is CORRECT?

A 72-year-old man undergoes right hemicolectomy for a 5 cm caecal mass. The pathologist receives the specimen and opens the bowel. The mass is exophytic and fungating, protruding into the lumen; on cross-section the cut surface shows tumour limited to the bowel wall but extending into the submucosa and muscularis propria without penetrating the serosa. All 18 lymph nodes are tumour-free. Histology shows moderately differentiated adenocarcinoma with intraluminal necrotic cellular debris. Which Dukes stage is CORRECT, and what single histological feature described is characteristic of conventional colonic adenocarcinoma?

A 45-year-old man with known FAP (familial adenomatous polyposis) undergoes routine surveillance colonoscopy. His father died of colorectal carcinoma at age 38. The colonoscopy reveals hundreds of small sessile polyps carpeting the entire colon. Biopsies of three polyps show tubular adenomas with low-grade dysplasia. A separate family member, a 48-year-old woman, is found to have 3 synchronous colorectal carcinomas; genetic testing shows microsatellite instability-high (MSI-H) status and germline MLH1 mutation. Which comparison between these two syndromes is CORRECT?

On a pathology practical slide, a student examines an H&E-stained section of large bowel resection. At low power, the tumour shows irregular, angulated glands of varying calibre lined by columnar cells with stratified hyperchromatic nuclei and prominent nucleoli. Within the lumina of many glands, the student observes eosinophilic amorphous material mixed with nuclear debris and inflammatory cells. No keratin pearls are identified. No mucinous lakes are present. The pathologist asks: 'What is the single most characteristic feature you can see that confirms this is a conventional colonic adenocarcinoma rather than another GI malignancy?'

A 28-year-old patient undergoing surveillance for longstanding Crohn's disease presents for review. He has had multiple bowel resections over 12 years, resulting in a total remaining small bowel length of 90 cm (normal 600–800 cm). He now has refractory diarrhoea, weight loss, and electrolyte disturbances requiring home parenteral nutrition. Concurrent investigations show a perianal fistula communicating between the rectum and perineal skin. Which pair of Crohn's disease complications is this patient demonstrating, and what is the morphological mechanism underlying fistula formation in Crohn's?

A first-year resident is reviewing a gastric resection specimen. The specimen shows an ulcer along the lesser curvature of the stomach, 1.8 cm in diameter. The ulcer base appears flat with clean edges that converge toward the centre. The surrounding mucosa shows radiating folds ('rugal convergence'). There is no heaped-up or everted edge. On histology: the ulcer base has four zones — a thin superficial layer of fibrinopurulent exudate, a zone of fibrinoid necrosis, a zone of granulation tissue, and deep scar tissue with fibrosis. The muscularis mucosae is absent at the ulcer base. Which interpretation of these combined gross and microscopic findings is CORRECT?