1. Diseases of small and large intestines Osvaldo Rubinstein, MD

2. Gastrointestinal Bleeding

3. Intestinal Obstruction

4. Loop of Normal small intestine with attached mesentery

5. Intestinal loops in a case of acute peritonitis

6. Liver from a case of acute perintonitis Notice the layer of yellow purulent exudate over the left lobe.

7. Histology from the previous specimen The liver parenchyma is on the right lined by exudate.

8. Liver tissue showing massive, recent coagulation necrosis

9. Diverticulosis of small intestine

10. Similar case Arrows are pointing to the opening of the diverticular sacs in the intestinal lumen.

11. Perforated intestinal diverticuli Notice the red, inflamed mucosa.

12. Acute diverticulitis The diverticular sac is lined by necrotic intestinal mucosa.

13. It originates in the intestinal loop opposite to the mesentery. Meckel’s diverticulum

14. Embryologic origin of the meckel’s diverticulum

15. Gross picture of a Meckel’s diverticulum showing gastric metaplasia with peptic ulcer.

16. Notice the opening of the diverticular sacs. Diverticulosis of large intestine

17. Histology of the previous lesion Notice the diverticular sac penetrating the muscular layer.

18. Colonic diverticulosis The diverticular sacs are easily seen.

19. Acute diverticulitis Purulent exudate is present in the lumen of the diverticular sac.

20. Chronic diverticulitis Notice the dense, white fibrous tissue among the diverticular sacs.

21. Histology of the previous lesion Notice the dense lymphocytic infiltrates surrounding the diverticular sacs.

22. Gangrene of small intestine Notice the dusky, black blue color of the intestinal loops.

23. Ischemic necrotizing enteritis (gangrene) The black necrotic areas are apparent.

24. Histology of the previous lesion Massive coagulation necrosis of the mucosa and submucosa admixed with bacterial colonies.

25. Gross picture of the descending aorta and both kidneys The arrow points to an embolus in the inferior mesenteric artery.

26. Paralitycus ileus Notice the dilated intestinal loops through the abdominal wall.

27. Intestinal obstruction caused by a fibrous band strangulating an intestinal loop

28. Diagram showing the morphology of intususception

29. Intususception caused by a mercury filled balloon

30. Diagram showing the anatomy of an hernial sac

31. Clinical presentation of a left hernial sac in the scrotum.

32. Intestinal atresia Fibrous band in the middle of an intestinal loop.

33. Abdominal distention in a patient with Hirschprung’s disease.

34. Gross specimen of Hirshprung’s disease Notice the dilated colon and rectum.

35. Meconium ileus The dark thick meconium is seen at the center of the slide.

36. Gallstone ileus Notice the big gallstone on the left of the slide.

37. Ischemic colitis The hemorhagic areas are representative of the ischemic necrosis.

38. Ischemic colitis Notice the black necrotic intestinal segment.

39. Histology of the previous lesion Notice the hemorrhagic necrosis of the intestinal mucosa.

40. Another case of ischemic colitis

41. Gross picture of a normal appendix

42. Gross picture of a case of acute appendicitis

43. Histology of the previous lesion Purulent exudate is seen at the center of the slide.

44. Severe case of acute Acute appendicitis The purulent exudate digested the entire intestinal mucosa and part of the muscular layer.

45. Markedly long appendix perforated at the tip

46. Similar case at higher magnification Notice the tiny hole of the perforation.

47. Markedly dilated appendix secondary to a mucocele

48. Histology of the previous case The appendeceal mucosa is lined by a papillary cyst adenocarcinoma.

49. Large amount of mucus removed from a case of pseudomyxoma peritonei

50. Histology of the previous case The peritoneal lining is lined by layers of mucus producing cells.

51. Chronic appendicits secondary to Schystosoma Mansoni

52. Similar case at higher magnification. The parasites are easily seen