11-8 (3,4) Gastric neoplastic
Terms
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- Classifications of Neoplasms
-
Epithelial
-Benign = Adenomatous polyps
-Malignant = Adenocarcinoma(90-95% of malig.)
.Intestinal type
.Diffuse type
Non-epithelial
-Benign = Leiomyoma
-Malignant = GI stromal tumors(2% of malig.), Lymphoma(4-5% of malig.) - Gastric Leiomyoma
-
Definition : benign smooth muscle tumor
Epidemiology : most common gastric tumor
Gross Pathology : well circumscribed
Histopathology : smooth muscle cells
Complications :
-Ulceration
-Hemorrhage - Gastric Polyps definition
-
Definition : focal protrusion of mucosa into lumen.
-2 types - Gastric Polyps types
-
Non-neoplastic = Hyperplastic
-Occur following injury(e.g. ulcers) and are composed of aggregates of inflammatory cells and regenerating mucosal cells.
- Common
Neoplastic = Adenomatous = Adenoma
-Benign proliferation of epithelium and stroma.
-Malignant potential, but is not the precursor for most gastric adenocarcinoma (unlike colon)
-Uncommon - new malignancies Gross patterns
-
Infiltrating = diffuse = linitis plastica
linitis plastica (leather bottle stomach)-extensive and involves most of the stomach - Gastric Metastases
-
1.Lymph nodes
-local lymph nodes
-left supraclavicular nodes (Virchow node)
-periumbilical
2.Local invasion
-pancreas, duodenum, peritoneal seeding
3.Distant sites (via hematogenous spread)
-lungs, liver, brain, ovary (Krukenberg tumor) - Gastric Adenocarcinoma Etiology
-
-multifactorial
Host genetics:
-IL-1B genotype
Environment:
-variety of dietary factors
Pre-existing disease :
-H. pylori infection
-Chronic atrophic gastritis
-Pernicious anemia - Gastric Adenocarcinoma Pathogenesis
-
pre-existing disease
->intestinal metaplasia
->dysplasia
->adenocarcinoma - Gastric Adenocarcinoma Locations
-
-Antropyloris(50-60%) > cardia(25%) > body-fundus
-Lesser curvature (40%)
-Greater curvature (12%)
-Therefore lesser curvature of antropyloric region is a common site. - Gastric Adenocarcinoma Morphology
-
-Early = spread only in mucosa +/- submucosa
-Advanced = spread into muscularis propria +/- serosa
-depth = prognostic factor(even superficial can mets)
-Sx arise w/ deeper involvement - Gastric Adenocarcinoma Types
-
1. Intestinal Type
2. diffuse type - Gastric Adenocarcinoma Intestinal Types
-
Pathogenesis:
-Chronic gastritis w/ intestinal metaplasia → dysplasia → adenocarcinoma
-Arises from metaplastic intestinal epithelium → intestinal gland +/- mucin
Growth : in expanding front - Gastric Adenocarcinoma Diffuse Types
-
Pathogenesis:
-Arises from gastric mucous cells → poorly differentiated,
-dis-cohesive (don't form glands) mucous cells = 'signet ring cells'
- +/- desmoplasia
Growth : infiltrative spread of single cells, cell clusters or sheets - Gastric Adenocarcinoma Prognostic factors
-
Significant prognostic features:
-depth of invasion(histologic stage)
-extent of nodal and distant metastases(clinical stage)
Not as significant : type of adenocarcinoma(i.e. intestinal and diffuse) - Gastric Lymphoma Basics
-
Names: gastric lymphoma = MALT lymphoma = MALToma
Type : low grade B cell lymphoma - Gastric Lymphoma Pathogenesis
-
Helicobacter pylori infection
->chronic inflammation(expansion of MALT) including influx of B cells; the likely substrate for lymphoma development. - Gastric Lymphoma Natural history
-
-some regress with H. pylori eradication
-indolent growth(excellent 5 yr survival s/p surgical removal)
-may transform to high grade lymphoma, with poorer survival - Gastric Lymphoma Gross
- any gross pattern
- Gastric Lymphoma Histopathology
- Small malignant lymphocytes infiltrate mucosa and destroy gastric glands (lymphoid-epitheliod lesion)
- H Pylori Prevalence/associations
-
Prevalence:50-60% worldwide
-Developing world = 70 - 80%
USA and developed world = 10 – 30%
Associations:
-Gastritis(acute and chronic) 80 - 90%
-Peptic ulcer disease 10 – 15%
-Gastric adenocarcinoma 1%
-Gastric MALToma 0.01% - H Pyloori, Dx / Tx
-
Diagnostic methods:
-Non-invasive: serology, stool, breath test
-Invasive or biopsy based: urease, histology
Treatment Regimen: PPI with 2 antibiotics for 10-14 days
recommended: PAC, PMC, PBMT - H. Pylori Transmition
-
-Gastro-Oral
-Vomit has highest bug load
-Black/hispanic - Gastric Cancer Epidemiology
-
-Second leading cause of cancer mortality
-Significant geographic variability(Asia=40-80, Latin America=10-50, USA=5-10
-Male-female ratio, 2:1
-Decreasing incidence globally - Gastric Cancer Clinical presentation
-
Insidious:
-dyspepsia
-nausea
-satiety
Advanced:
-emesis
-bleeding
-mass - Gastric Cancer Diagnosis/prognosis
-
-Endoscopy as procedure of choice
-Staging: CT, EUS, Surgery
-Prognosis:TMN staging system