Alimentary Tract. Wang Lin 王琳 Department of pathology School of basic medical sciences

Transcription

1 Alimentary Tract Wang Lin 王琳 Department of pathology School of basic medical sciences

2 Alimentary Tract Carcinoma Peptic ulcer Carcinoma Gastritis Peptic ulcer Carcinoma Appendicitis

3 Anatomy of the stomach Lesser curvature Greater curvature

4 Normal appearance of the stomach fundic mucosa 胃底 antral mucosa 胃窦

5 Gastritis Overused Missed

6 Gastritis 胃炎 Acute gastritis often due to chemical injury (alcohol, drugs) Chronic gastritis type Etiology and Pathogenesis locus of lesion A B autoimmune injury corpus infection of H. pylori auto-antibody (+) C chemical damage antrum or whole stomach

7 Chronic gastritis -- type A Autoantibodies to parietal cells and/or intrinsic factor -- Autoimmune gastritis Involves the body and the fundus Loss of parietal cells. Decreased acid secretion Increased serum gastrin (G-cell hyperplasia) Pernicious anemia: megaloblastic anemia due to lack of intrinsic factor and B12 malabsorption

8 Helicobacter pylori Biological Pattern G - bacilliform, m, 37, ph 7.0~7.2 Adhere to surface of gastric epithelium

9 HP---the rate in gastric diseases Epidemiology The rate of infection is 50%~70%, increased with age. Chronic gastritis 53%~95% Peptic ulcer in stomach 60%~100%, average 84% Peptic ulcer in duodenum 90%~100%, average 95% Gastric carcinoma 43%~78% Lymphoma in stomach >90%

10 Chronic gastritis HP gastritis, involves antrum and pylorus Autoimmune gastritis, involves body and fundus

11 Pathology of HP gastritis (type B) Antral type, high acid production, high risk for duodenal ulcer Pangastritis, mucosal atrophy, low acid secretion, increased risk for adenocarcinoma HP on the mucosal surface Intraepithelial and lamina propria neutrophils Lymphoid aggregate with germinal centers

12 Chronic gastritis Chronic gastritis is defined histologically as an increase in number of lymphocytes and plasma cells in the gastric mucosa. Pathological changes Chronic superficial gastritis Chronic atrophic gastritis Chronic hypertrophic gastritis

13 Chronic superficial gastritis Involves the subepithelial region around the gastric pits Grossly: hyperemia, edema, redness, petechiae, erosion Antrum

14 Chronic superficial gastritis normal Microscpically: congestion, edema, inflammatory infiltrate of lymphocytes and plasma cells lesion is limited to upper third (1/3)of the gastric mucosa

15 Chronic atrophic gastritis Normal mucosa Chronic atrophic gastritis mucosa thin, folds flatten

16 Chronic atrophic gastritis normal Lymphocytic and plasma cell infiltrate Gland loss and mucosal atrophy Intestinal and pseudopyloric metaplasia atrophic lymph follicle

17 Chronic atrophic gastritis Chronic inflammatory cell infiltration Mucosal atrophy Intestinal (goblet cell) metaplasia metaplasia normal

18 Hypertrophic gastritis (gastropathy) normal Gross: enlarged rugal folds in the body and fundus Decreased acid production Fundus Corpus

19 Hypertrophic gastritis ( Menetrier s disease ) normal LM: massive hyperplasia of the surface mucous cells with accompanying glandular atrophy

20 Gastritis

21 Consequences of gastritis Peptic ulcer disease (Helicobacter) Adenocarcinoma (all types)

22 Peptic ulcer The peptic ulcer are defects in the mucosa that penetrate at least into the submucosa, and often into the muscularis propria or deeper. Most are round, sharply punched-out craters less 2 cm in diameter.

23 Peptic Ulcer Morphology Locations: 90% ulcers in first portion of duodenum or lesser curvature of stomach(4:1) Gross: 80 to 90% cases single ulcer. Round Small ulcers with sharply punched out edges, clean base Microscopy: 4 zones Inflammatory cells zone Necrotic layer Granulation tissue zone Collagenous scar layer

24 Gastric peptic ulcer Etiology: Associated with H. pylori (75%) Location: lesser curvature of the antrum Gross - Small <2 cm, solitary ulcers - Round or oval shape - Sharply demarcated, "punched-out" ulcers - Over hanging margins - Radiating mucosal folds, - Base clean, flat, smooth Classic presentation: burning epigastric pain, which worsens with eating

25 inflammatory exudate Necrotic materials Granulation tissue scar Microscopic features of gastric peptic ulcer

26 Peptic Ulcer fibrin and inflammatory exudate necrosis granulation tissue scar

27 Duodenal peptic ulcer 十二指肠溃疡 More common than gastric ulcers Associations H. pylori (~100%), Increased gastric acid secretion Increased rate of gastric emptying Blood type O Classic presentation: burning epigastric pain 1-3 hours after eating, which is relieved by food

28 Morphologic features of duodenal ulcer Location: anterior wall of the proximal duodenum Shape: Resemble gastric ulcer, round -to-oval, sharply punched-out defect with relatively straight walls and essentially flat adjacent mucosa Size: usually small, diameter <1cm

29 Sequel and complications of peptic ulcer Healing Haemorrhage by erosion of vessel in base Perforation leading to peritonitis Pyloric stenosis: congestion and edema, scarring (Cancer rare event in true peptic ulcer)

30 Complications of peptic ulcer Haemorrhage Haemorrhage Perforation carcinoma carcinoma

31 Pathogenesis of peptic ulcer Peptic ulcers are produced by an imbalance between the gastro-duodenal mucosal defense mechanisms and damaging forces of gastric acid and pepsin, combined with superimposed injury from environmental or immunologic agents. Defensive Defensive barrier barrier Destructive Destructive factors factors

32 Pathogenesis of peptic ulcer

33 It is a common disease Appendicitis 阑尾炎 Peak incidence is in the second and third decades Males are affected more often than females Right lower quadrant pain, fever, neutrophil number increase, nausea and vomiting Two types : acute appendicitis chronic appendicitis

34 Acute appendicitis Characterized by= Obstruction of lumen by fecalith Raised intraluminal pressure Ischemic injury & Bacterial invasion Morphology Acute simple appendicitis Acute suppurative (phlegmonous) appendicitis Hyperemia, edema & neutrophils infiltration of all layers of the wall to the peritoneum Acute gangrenous appendicitis Thrombosis of appendicular vessels gangrene diffuse septic peritonitis.

35 Acute simple appendicitis 急性单纯性阑尾炎 normal normal Appendix is slightly swollen. Subserosal vessels are congested. Only a scant neutrophilic exudate may be found throughout the mucosa, submucosa, and muscularis propria.

36 Acute phlegmonous appendicitis 急性蜂窝织炎性阑尾炎 normal The top image exhibits a fibrinopurulent exudate on the serosa. The bottom image exhibits fecoliths within the lumen. the wall of the appendix is thickened

37 Acute phlegmonous appendicitis 急性蜂窝织炎性阑尾炎 Ulceration and extensive neutrophilic exudate through the appendix wall Heavy coating of purulent exudate on the serosa

38 Chronic appendicitis

39 Tumor of alimentary tract carcinoma Esophageal carcinoma Gastric carcinoma Colorectal carcinoma

40 Carcinoma of the esophagus Etiology Dietary, Environmental factors, HPV Location: upper third(20%), middle third(50%), lower third(30%) Staging: Superficial (early) carcinoma: asymptomatic Advanced carcinoma (progressive): symptomatic

41 Early (superficial) esophageal carcinoma It is defined as the carcinoma confined to the mucosa and/ or submucosa with or without spread to regional lymph nodes. normal 粘膜 粘膜下层 肌层 上 1/4 为骨骼肌 下 1/2 为平滑肌 中 1/4 混

42 Early (superficial) esophageal carcinoma invasion into the submucosa

43 Advanced esophagus carcinoma Protruded Ulcerative Stenotic Sclerotic Medullary

44 Advanced esophageal carcinoma Pathologic features squamous cell carcinoma, most common adenocarcinoma small cell carcinoma adeno-squamous carcinoma

45 Squamous cell carcinoma of the esophagus Epidemiology: SCC is the most common type of esophageal cancer in the world. Males> females; age usually >50 Risk factors: Heavy smoking and alcohol use Location: middle third (50%) lower third (30%), upper third (20%) Presentation:. Often asymptomatic until late in the course. Progressive dysphagia. Weight loss and anorexia. Hoarseness or cough (advanced cancers). Poor prognosis

46 Squamous cell carcinoma of the esophagus Cancer nest Large ulcerated SCC Keratin pearl

47 Adenocarcinoma of the esophagus More common than SCC in the United States Arises in the distal esophagus (lower third) Associated with Barrett esophagus and dysplasia Poor prognosis

48 Barrett esophagus It is a complication of long-standing gastroesophageal reflux. The distal squamous mucosa is replaced by metaplastic columnar epithelium as a response to prolonged injury. squamous mucosa and intestinal-type columnar epithelial cells (goblet cells) in a glandular mucosa

49 Adenocarcinoma of the esophagus An ulcerated, exophytic mass at the gastroesophageal junction, arising from the mucosa of Barrett esophagus. Malignant glands in adenocarcinoma arising from Barrett esophagus

50 Spread of esophageal carcinoma Invasion of bronchial wall may lead to the tracheoesophageal fistulae. Invasion of the aorta may result in massive hemorrhage. Recurrent laryngeal nerve involvement leads to vocal cord paralysis (hoarseness). Lymphatic spread to the tracheo-bronchial LN, cardia and abdomen LN Bloodstream spread to liver and lung

51 Gastric carcinoma Risk factors Dietary factors, Smoked fish and meats, Pickled vegetables, Nitrosamines, Benzpyrene Decreased intake of fruits and vegetables H. pylori infection. Chronic atrophic gastritis Smoking Blood type A Bacterial overgrowth in the stomach Prior subtotal gastrectomy Menetrier disease

52 Gastric carcinoma Presentation Often (90%) asymptomatic until late in the course Weight loss and anorexia Epigastric abdominal pain mimicking a peptic ulcer Early satiety Occult bleeding and iron deficiency anemia Location: lesser curvature and antrum (75%)

53 Early gastric carcinoma It is defined as a lesion confined to the mucosa and or submucosa regardless of whether spread has occurred to regional lymph nodes. Protruded type Superficial type Excavated type There is a protrusion of a tumor mass into the lumen there is no obvious tumor mass within the mucosa a shallow or deeper erosive crater is present in the wall of the stomach

54 Early gastric carcinoma Protruded type superficial elevated type Superficial type superficial flat type superficial depressed type Excavated type

55 Early gastric carcinoma protruded type superficial depressed type

56 Early gastric carcinoma protruded type superficial elevated type superficial depressed type excavated type

57 Advanced gastric carcinoma It is a neoplasm that has extended below the submucosa into the muscular wall and has perhaps spread more widely.

58 Advanced gastric carcinoma Polypoid type Ulcerative type Infiltrating tumors normal

59 Comparison between benign and maligmant ulcer in appearance benign ulcer malignant ulcer

60 Comparison between benign and maligmant ulcer in appearance Benign ulcer Malignant ulcer Shape Round to oval Irregular Size <2cm in diameter >2cm in diameter Depth Deeper Shallow Mucosal folds Radiating Interrupted Margin Regular, flatten Irregular, heaped-up, beaded Ulcer bed Smooth and clean or hemorrhagic Shaggy, necrotic and hemorrhagic

61 Comparison between benign and maligmant ulcer

62 Infiltrating type --Linitis Plastica Type A diffuse infiltrative gastric adenocarcinoma which gives the stomach a shrunken "leather bottle" appearance with extensive mucosal erosion and a markedly thickened gastric wall.

63 Advanced gastric carcinoma Adenocarcinoma Mucous adenocarcinoma Signet-ring cell carcinoma Undifferentiated carcinoma

64 Advanced gastric carcinoma Gastric adenocarcinoma

65 Advanced gastric carcinoma Mucinous adenocarcinoma Mucin pool

66 Advanced gastric carcinoma Signet-ring cell carcinoma The cells are filled with mucin vacuoles that push the nucleus to one side

67 Spread of gastric carcinoma Local infiltration (through wall of stomach to peritoneum, pancreas etc) Lymphatic regional and distant, Blood liver, lungs left supraclavicular lymph nodes Implantation metastasis: Transcoelomic (across peritoneal cavity). Often involves ovaries (esp. signet ring cancer) Krukenberg tumour.

68 Colorectal Carcinoma Etiology and Pathogenesis Genetic factors Enviromental influences : dietary habit Adenoma-carcinoma sequence pathway Serrated route to carcinoma pathway Ulcerative colitis associated cancer pathway Juvenile polyposis-carcinoma pathway

69 Colorectal Carcinoma 50% of large intestinal cancers arise in the rectum 20% arise in the sigmoid colon 16% arise in the cecum and ascending colon the remainder arise in the transverse and descending colon The majority of colonic cancers are adenocarcinomas, a small number of squamous carcinomas that arise from the anal canal. 8% 16% 6% 50% 20%

70 Four gross patterns of colorectal cancer Polypoid type, which is a large bulky cauliflower growth with papillary surface projections. Ulcerating tumors are crater-like ulcers with hemorrhage and necrosis in the base and heaped-up margins. These tumors have a firm consistency. Infiltrating tumors contain plenty of fibrous tissue. These tumors infiltrate diffusely to lead to stenosis, thickening and obstruction of the bowel. Mucoid carcinoma. On cut section mucoid carcinoma is gelatinous because of the large amount of secreted mucus. It has an appearance like colloid.

71 Pathological changes of colorectal carcinoma Ulcerating Polypoid Infiltrating

72 Colonic Adenocarcinoma Papillary adenocarcinomas Tubular adenocarcinomas Mucoid adenocarcinoma Signet-ring carcinoma

73 The Modified Dukes' Staging System A Limited to the mucosa and submucosa Bl Invasion into but not through the muscularis propria B2 Invasion through the muscularis propria Cl Positive lymph nodes; invasion into but not through the muscularis propria C2 Positive lymph nodes; invasion through the muscularis propria D Distant metastasis

74 Right-Sided Cancer Versus Left-Sided Cancer Right-Sided Cancer Proximal colon Left-Sided Cancer Distal colon Gross Polypoid mass Circumferential growth producing a "napkin ring" configuration Barium studies Polypoid mass "Apple core" lesion Presentation Bleeding Occult blood in stool Iron deficiency anemia Change in bowel habits Constipation or diarrhea Reduced caliber stools Obstruction

75 Colorectal Carcinoma Diagnosis Hemoccult positive stool Endoscopy with biopsy Pattern of spread Lymphatic spread to mesenteric lymph nodes Distant spread to liver, lungs, and bone

76 Summary Morphological features of chronic atrophic gastritis and appendicitis. Morphological features of peptic ulcer and gross differences with malignant gastric ulcer. Complications of peptic ulcer. Location, gross and histological types of common tumors.

77 Peptic Ulcer