Pathology of the Upper Digestive Tract

Comprehensive vocabulary flashcards covering congenital anomalies, motility disorders, inflammatory diseases, ulcers, neoplasms, and enteropathies of the esophagus, stomach, and duodenum.

Inlet patch

Ectopic gastric mucosa located in the upper third of the esophagus, found in about $2\%$ of the population, which can release acid and cause dysphagia, esophagitis, or Barrett esophagus.

Agenesis

The complete failure of an organ or tissue to develop during embryonic development.

Atresia

A congenital defect in which a normal body opening, passage, or duct is absent, closed, or fails to develop properly.

Congenital stenosis

The congenital narrowing of a normal anatomical lumen, opening, or passage.

Oesophageal atresia

A congenital malformation where the esophagus fails to form a continuous patent tube, being replaced in part by a thin, non-canalized fibrous cord that creates two blind pouches and often forms a fistula with the trachea or bronchus.

Mucosal web

A ledge-like mucosal protrusion consisting of a thin layer of extra tissue growing across the esophageal lumen that causes mechanical obstruction.

Mucosal ring (Schatzki ring)

A thin, concentric circular band of tissue containing mucosa, submucosa, and occasionally a muscular layer that narrows the lumen of the lower esophagus.

Achalasia

A primary esophageal motility disorder caused by degeneration of distal esophageal nerves, characterized by aperistalsis, elevated lower esophageal sphincter resting tone, and incomplete sphincter relaxation during swallowing.

Mallory-Weiss syndrome

Longitudinal mucosal tears located at the gastroesophageal junction or gastric cardia caused by forceful, repetitive retching or vomiting, responsible for $5\text{--}10\%$ of upper gastrointestinal bleeding episodes.

Esophageal varices

Markedly dilated, tortuous submucosal veins in the distal esophagus resulting from portal hypertension (most commonly in cirrhosis), presenting a severe medical emergency with a $50\%$ mortality rate per bleeding episode.

Hiatal hernia

The herniation or upward displacement of a portion of the stomach into the thorax through the esophageal hiatus of the diaphragmatic crura.

Axial (sliding) hiatal hernia

A form of hiatal hernia in which both the gastroesophageal junction and an upper part of the stomach slide superiorly above the diaphragm into the thoracic cavity.

Paraesophageal hiatal hernia

A type of hiatal hernia where the gastroesophageal junction remains in its normal position below the diaphragm, while a portion of the stomach protrudes through the hiatus alongside the esophagus.

Reflux oesophagitis

Esophageal mucosal inflammation caused by the backward flow of gastric acid, morphologically marked by intraepithelial eosinophils, basal hyperplasia exceeding $20\%$ of epithelial thickness, and elongated lamina propria papillae.

Barrett's oesophagus

A condition occurring in approximately $10\%$ of individuals with chronic GERD, where stratified squamous epithelium of the distal esophagus is replaced by metaplastic columnar intestinal epithelium, increasing the risk of esophageal adenocarcinoma.

Non-reflux oesophagitis

Inflammation of the esophagus induced by causes other than gastric reflux, such as infections (Candida, HSV, CMV), corrosive substances, radiation therapy, cytotoxic cancer drugs, or uremia.

Oesophageal squamous cell carcinoma

A malignant epithelial neoplasm arising from the squamous lining of the upper and middle esophagus, characterized microscopically by keratinisation and intercellular bridges.

Oesophageal squamous cell carcinoma in situ

A high-grade intraepithelial neoplasm displaying nuclear atypia, hyperchromasia, and atypical mitotic figures across the esophageal squamous epithelium without breach of the underlying basement membrane.

Oesophageal adenocarcinoma

A malignant epithelial tumor displaying glandular differentiation that arises predominantly in the lower third of the esophagus, classically evolving through dysplastic progression in Barrett's esophagus.

Congenital hypertrophic pylorostenosis

Congenital hypertrophy and hyperplasia of the pyloric smooth muscle producing gastric outlet obstruction, which characteristically presents clinically in infants during the 2nd to 3rd week of life.

Acute gastritis

An acute transient inflammatory mucosal injury of the stomach characterized by neutrophilic infiltration, mucosal edema, vascular congestion, superficial epithelial erosion, and hemorrhage.

Chronic gastritis

Persistent gastric mucosal inflammation marked by infiltration of lymphocytes, plasma cells, and macrophages within the lamina propria, potentially leading to glandular atrophy and epithelial metaplasia.

Active chronic gastritis

A state of chronic gastritis where neutrophilic granulocytes infiltrate the mucosal epithelium and glands alongside chronic mononuclear cells, signifying ongoing active mucosal injury typically related to Helicobacter pylori infection.

Active secondary lymphoid follicle (gastric)

An organized follicular collection of B lymphocytes with a pale germinal center within the gastric mucosa, formed in response to sustained antigenic stimulation such as persistent Helicobacter pylori infection.

Peptic ulcer

A well-demarcated breach in the acid-exposed gastrointestinal mucosa that penetrates through the muscularis mucosae, most commonly located in the duodenal bulb and gastric antrum, with a $4:1$ duodenal to gastric ratio.

Gastric cancer T4 stage

A TNM staging category indicating that a primary gastric carcinoma has penetrated the serosa (visceral peritoneum) or directly invaded adjacent structures and organs, such as the spleen.

Lauren classification: Intestinal type

A morphological variant of gastric adenocarcinoma characterized by malignant cohesive cells forming discrete glandular and tubular structures, frequently linked to chronic atrophic gastritis and Helicobacter pylori infection.

Lauren classification: Diffuse type

A morphological variant of gastric adenocarcinoma characterized by poorly cohesive, discohesive single tumor cells infiltrating the stomach wall without gland formation, often associated with CDH1 mutations and signet ring cells.

Signet ring cell

An adenocarcinoma cell containing an expansive intracytoplasmic mucin droplet that pushes and flattens the nucleus against the cell periphery, characteristic of diffuse gastric carcinoma.

Gastric MALT lymphoma

An extranodal low-grade B-cell non-Hodgkin lymphoma arising from mucosal lymphoid tissue of the stomach, associated with Helicobacter pylori in approximately $80\%$ of cases and capable of regressing following antibiotic eradication.

Peptic duodenitis

Inflammation of the proximal duodenum induced by excessive gastric acid injury, histologically featuring epithelial damage, Brunner gland hyperplasia, and foveolar metaplasia.

Foveolar metaplasia

A reparative mucosal adaptation in the duodenum where the surface epithelium transforms into gastric-type foveolar mucus-secreting cells in response to acidic irritation.

Celiac disease

An immune-mediated enteropathy triggered by the ingestion of gluten (gliadin) in individuals carrying HLA-DQ2 or HLA-DQ8 haplotypes, characterized by mucosal intraepithelial lymphocytosis, crypt hyperplasia, and villous atrophy.

Marsh classification

A histological classification system assessing duodenal biopsy damage in celiac disease, graded from stage 0 (normal) to stage 4 (hypoplasia with total villous and crypt atrophy).

Villous subatrophy

Partial shortening, blunting, and flattening of the intestinal villi associated with crypt hyperplasia and intraepithelial lymphocytes, corresponding to Marsh stage 3 in celiac disease.

Whipple disease

A rare systemic bacterial infection caused by Tropheryma whipplei that primarily impairs intestinal absorption and is characterized by marked accumulation of PAS-positive foamy macrophages in the lamina propria.