Stomach

Stomach

1. Pyloric Stenosis

   • genetic
     • first male child
     • concentric hypertrophy of circular muscle layer
     • Regurgitation, PROJECTILE vomiting, palpable epigastric OLIVE-LIKE mass, visible peristalsis
     • Treatment: MYOTOMY of the hypertrophied stomach and the stenosed part
   • Acquired
     • Chronic antral gastritis, peptic upcelrs, malignancy

2. Gastritis

   • ACUTE
     • RISK
       • NSAIDS
         • Inhibit Prostaglandin synthesis
           • No mucus
       • alcohol
       • Smoking
         • Toxins that damage the mucosa
       • Ischemia/ SHOCK
       • Burn (Curling Ulcer)
         • Hypovolemia
           • Less blood flow to the stomach
             • systemic Acidocic
       • Infections
       • Uremia
       • Head trauma (Cushing Ulcer)
         • Increased intracranial pressure
           • increased vagal stimulation to reduce hypoxia (PSNS)
             • increased ACh
               • activates parietal cells
                 • increased acid secretion
         • Hypoxia
       • Chemotherapy
     • Mucosal erosion
       • Edema and congestion of lamina propria
     • Neutrophils in surface epithelial glands
     • Epigastric pain, nausea, vomiting
     • Hematamesis
     • Complication
       • Acute Gastric Ulcer
         • multiple small ulcers with non-indurated bases
         • normal gastric rugae
     • NOT -itis - NOT inflammation
     • hyperemia, and hemorrhage
   • CHRONIC
     • AUTOIMMUNE Chronic Gastritis
       • Fundus/ body
       • Type II HS
       • NO Lymphoid aggregates
       • destroy parietal cells
         • achlorhydria
           • can't cleave pepsinogen
             • NO relief with Anti-acid because there's no acid produced to begin with due to anti parietal Ab
       • Atrophic Gastritis
         • fundus/ body becomes antralized
       • Intestinal metaplasia
         • dysplasia
           • intestinal gastric adenocarcinoma
       • G- cell hyperplasia
         • increase gastrin
           • increase enterochromaffin
             • Dysplasia
               • Type I carcinoid
             • preneoplastic - produces histamine
       • Pernicious anemia
         • decrease IF
           • decrease B12
             • increase methylmalonic acid
               • Neurological defic
     • H. pylori
       • Chronic Gastritis
         • Antrum - lesser curvature
         • lymphoid aggregates in LP
           • + neutrophils = Chronic ACTIVE Gastritis
           • uncontrolled B cells
         • Produce urease > amonia to neutrolize acid, phospholipase to break through mucosa,
           • diffuse effacement of mucosa by lymphocytes
             • peptic ulcer/ chronic gastritis (> 2cm)
               • duodenum, stomach, GE junction, margins of gastrojej, Meckel's, Zollinge _ food makes it better _ worse at night _ gastric obstruction
         • Complication: infla >> intestinal metaplasia >> dysplasia
         • UREA IN BREATH, endoscopy (rapid urease test), silver stain, regression of tumor with Ab (CONFIRMATORY), Ag in stool, PCR of saliva, IgA, IgG
       • Chronic Gastric Ulcer
         • PRE-MALIGNANT
           • Lesser curvature (more common)
           • Greater curvature (less common BUT higher chance of malignancy)
         • Punched out ulcer with sharp raised margins
         • Also caused by
           • NSAIDs
           • Tobaco
           • Alcohol
           • Psych stress
           • Zollinger Ellison Syndrome
         • rugae - spokes of a wheel
         • Stages:
           • N: Necrosis
             • I: Infla cells (lymphocytes, plasma, PMNs
               • G: granulation tissue (Type III collagen)
                 • S: Scar (Type I collagen)
         • complications: Melena _ Iron deficiency anemia _ perforation (peritonitis) _Obstruction as it heals via scarring (PROJECTILE VOMITING _ hematemesis _ malignant transformation (intestinal)
         • Pain upon eating at night - weight loss because they're scared to eat
       • Duodenal Ulcer
         • MOST COMMON
         • NEVER MALIGNANT
         • Eating makes it better!
       • MALToma
         • dyspepsia, abdominal pain, nausea, vomiting, WL
         • Treat with Ab, chemotherapy/ Rituximab (if relapses - 10% of cases)
         • Extranodla marginal zone lymphoma
       • Gram (-) on surface of lumen
         • intestinal gastric adenocarcinoma
           • Japan, South Korea
           • Also caused by : autoimmune, smoked food, nitrosamines
           • malignant glands that make mucin invade the submucosa and muscularis propria (PROGNOSIS: DEPTH OF INVASION) (Early: mucosa to submucosa _ Advanced: beyond muscularis)
           • Type 1: Diffuse - Young women - familial
             • Mutation E-cadherin - signet ring cells with mucin - leather bottle stomach/linitis plastica"
               • NO INTESTINAL METAPLASIA
                 • Complications (diffuse ONLY): Krukenberg tumor (ovarain metastasis) -- also comes from invasive lobar carcinoma of breast and colon cancer
           • Type 2: Intestinal - Elderly
             • her2neu/EGF
               • Chronic Gastritis
                 • intestinal metastasis
           • epigasric mass / pain / early satiety / cachexia (TNF alpha)) / bleeding / melena (iron deficiency anemia)
           • General complication: supraclavicular/ Virchow's LN metastasis
           • Periumbilical metastasis >> Sister Mary Joseph nodule
           • CEA: PGCLubs - Pancreas, Gallbladder, Colon, Lungs, Breast, Stomach
     • mucosal atrophy and epithelial metaplasia - nausea, vomiting, dyspepsia
     • Smoking and alcohol, anterectomy, radiation, Chron's, Sarcoidosis

3. Gastrointestinal Stromal Tumor (GIST)

   • #1 mesenchymal tumor in GIT (stomach mostly
   • derived from interstitial cells of Cajal (pacemaker cells)
   • Express CD117 (c-Kit) with - majority have c-Kit mutation on exon 11
   • Spindle-shaped tumor cells - submucosal
   • Treatment: TKI (Imantinib, Gleevec) Same treatment as Chronic Myeloid Leukemia