Practical Pathology

PART I.. The Sources of Pathologic Material and the

THE SOURCES OF PATHOLOGIC MATERIAL AND THE METHODS OF OBTAINING IT FOR EXAMINATION.

CHAPTER PAGE

Introduction 1

I. The Autopsy: General Considerations 3

II. The Order of the Autopsy 24

III. The Protocol 33

IV. The External Examination 41

V. The Examination of the Spinal Cord 53

VI. The Examination of the Head 63

VII. The Main Incision: Thorax and Abdomen 96

VIII. The Examination of the Thorax 106

IX. The Examination of the Mouth and Neck 131

X. The Examination of the Abdomen 140

XI. The Examination of the Pelvic Organs 160

XII. Special Regional Examination 173

XIII. The Autopsy of the New-born 177

XIV. The Medicolegal Autopsy 187

XV. The Restoration of the Body 193

XVI. Other Sources of Pathologic Material 196

PART II.. The Treatment of the Material.

THE TREATMENT OF THE MATERIAL.

Introduction 199

XVII. The Laboratory Outfit 201

XVIII. The Examination of Fresh Material 208

XIX. The Preservation of Macroscopic Preparations 222

XX. The Fixation and Hardening of Tissues 225

XXI. Decalcification 232

XXII. Imbedding 234

XXIII. Section-cutting 238

XXIV. The Preparation of Mounted Sections 243

XXV. Staining and Staining Methods.—Nuclear and Protoplasmic Stains 253

XXVI. Special Staining Methods for the Demonstration of Pathologic Conditions in Cells or Tissues 262

XXVII. The Staining of Pathogenic Micro-organisms in Tissues 277

XXVIII. The Staining of Special Organs and Tissues 288

XXIX. Microscopic Examinations for Medicolegal Purposes 305

XXX. The Study of Mounted Preparations 309

LIST OF ILLUSTRATIONS

FIGURE PAGE

1. Large section, or cartilage knives 10

2. Scalpels 10

3. Long section knife 11

4. Myelotome 11

5. Autopsy scissors of various types 12

6. Enterotome 13

7. Costotome 13

8. Large autopsy saw 13

9. Small autopsy saw 14

10. Hey’s saw 14

11. Luer’s rhachiotome 14

12. T-chisel or skull-opener 14

13. Hatchet chisel 14

14. Straight bone chisel 14

15. Brunetti chisels 15

16. Steel hammer 15

17. Wooden mallet 15

18. Forceps 15

19. Bone-forceps 16

20. Bone-nippers 16

21. Probe 16

22. Blow-pipe 16

23. Hand bone-drill 17

24. Needles 18

25. Brass measuring-stick 18

26. Author’s method of removing skull-cap 65

27. Skull-cap after removal, showing interlocking joint 67

28. Method of examination of brain (after Nauwerck) 71

29. Section of brain. Ventricles opened (after Nauwerck) 72

30. Method of Pitres 75

31. Base of cranium after removal of brain (after Nauwerck) 79

32. Incisions for examination of orbit, ear and nose 80

33. Tympanic cavity after removal of tegmen (after Politzer) 81

34. Sagittal section through left middle ear, outer half (after Politzer) 84

35. Sagittal section through left middle ear, inner half (after Politzer) 84

36. The main incision completed (after Nauwerck) 97

37. Method of disarticulating sternoclavicular articulation (after Nauwerck) 101

38. Section of left ventricle and auricle (after Nauwerck) 108

39. Removal of heart (after Nauwerck) 112

40. Section of right auricle and ventricle, Nauwerck method 114

41. Incision for opening of aortic ring (after Nauwerck) 115

42. Section of left lung (after Nauwerck) 118

43. Section of right lung (after Nauwerck) 119

44. Removal of neck organs (after Nauwerck) 132

45. Section of male pelvic organs (after Nauwerck) 162

46. Section of female pelvic organs (after Nauwerck) 164

47. Method of opening abdomen of new-born (after Nauwerck) 178

48. Section of pulmonary artery in new-born (after Nauwerck) 179

49. Method of demonstrating Béclard center (after Nauwerck) 180

50. A satisfactory microscope for the working laboratory 202

51. A good practical microtome 206

52. Cathcart freezing microtome 212

53. Carbonic-acid freezing microtome, Becker model 213

54. Bardeen freezing microtome 214

55. Knife for Bardeen freezing microtome 215

PART I.. Sources of Pathologic Material and Methods of Obtaining It for

SOURCES OF PATHOLOGIC MATERIAL AND METHODS OF OBTAINING IT FOR EXAMINATION.

INTRODUCTION.

The chief sources of pathologic material are the autopsy, surgical operation, diagnostic excision and curetting, the spontaneous discharge of diseased tissue, and the experimental production of pathologic conditions in animals. To these sources may be added the blood and other body-fluids, as well as pathologic fluids, exudates, effusions, cyst-contents, etc., particularly the cellular elements found in the sediment of such fluids.

That an accurate pathologic diagnosis be secured, the material must first be properly obtained, its gross characteristics carefully noted, the portion to be examined microscopically chosen with discrimination, and, finally, the microscopic examination itself carried out along the various lines indicated. All of these procedures require the knowledge of a certain amount of technique, and the general principles of such technique should be familiar to every student of medicine. While it is not possible that every medical graduate can enter into the active practice of his profession as an expert pathologist, yet the possession of the technical knowledge necessary to perform an autopsy properly and to select with discrimination the tissue for microscopic examination gives to a physician a distinct practical advantage. This advantage becomes the greater if to the possession of this knowledge there be added also a practical working knowledge of the technique necessary for the microscopic examination and diagnosis. Not that this knowledge should be so extensive as to cover the great field of special methods; all that is really essential is a knowledge of the general principles of laboratory examinations; and a very large proportion of practical work can be successfully carried out if the physician possesses this foundation knowledge. In the first days of practice a young physician so equipped often finds that his laboratory training comes to be his chief source of income and opens the way to a successful professional career. It constitutes a professional asset which the older practitioner usually does not possess.

CHAPTER I.. The Autopsy: General Considerations.

THE AUTOPSY: GENERAL CONSIDERATIONS.

1. =AUTOPSY= (=Postmortem examination=, =necropsy=, =necroscopy=, =obduction=, =mortopsy=, =section=; Latin, =sectio cadaveris=, =sectio anatomica=, =autopsia cadaverica=, =sectio=, =obductio=; French, =autopsie cadaverique=, =nécropsie=; German, =Leichenschau=, =Section=, =Obduction=) is the term preferably applied to the examination of the dead body, conducted for the purpose of ascertaining the cause of death, for the study of the pathologic conditions present with reference to their nature and cause, or for the obtaining of anthropologic, anatomic or surgical data. When carried out primarily with the view of obtaining evidence of legal importance, as in the case of a suspected crime, accidental death, the identification of a body, in damage suits for injuries received, malpractice, insurance, etc., the autopsy is usually styled =medicolegal=, or the German term =obduction= is not infrequently applied. The terms =prosector= and =obducent=, although used originally in a medicolegal sense, are now generally applied to the person performing the autopsy whether medicolegal or not.

2. =IMPORTANCE OF THE AUTOPSY.= The opportunity of performing an autopsy should be regarded by the physician and student as a very great privilege. Even to the prosector with an experience of several thousand autopsies to his credit, each new examination of a dead body becomes a new revelation and extends still farther his intellectual horizon. To the student and physician in practice each autopsy may, if performed in the proper spirit, become in itself an educational factor of the greatest value. In no other scientific procedure is there such a demand made upon the faculties of observation, judgment and interpretation, and in no other is there such intimate correlation between methods of technique and the higher intellectual processes. It is unnecessary to add that the ability to perform an autopsy in the proper manner presupposes a foundation of accurate anatomic and pathologic knowledge as well as a capacity for careful work.

Primarily, the aim of the autopsy is to ascertain the cause of death and to acquire knowledge of the changes produced in the tissues and organs by the disease-process. If for no other purpose than that of extending our knowledge of disease, the autopsy becomes the most valuable factor in furthering the development of medical science. We have but entered into the broad, rich fields of pathology; at any time new facts may be discovered or observations of the most far-reaching nature made. From year to year the statistics of the most common diseases must be revised in the light of new conceptions of disease. Through the autopsy there lies within the reach of every practitioner the opportunity of contributing something worth while to the general sum of medical knowledge. There is not a pathologic condition in the medical category that does not call out for illumination upon some point or other. The phenomena of malignant tumors, the earliest stages of the so-called chronic affections, as well as the majority of the infectious diseases, require further autopsy observations for their elucidation. The autopsy establishment of the diagnosis is also of the greatest importance in giving value to vital statistics. Until we have a more universal confirmation of the clinical diagnosis by the pathologic our vital statistics must of necessity be imperfect.

To the practitioner the autopsy offers further a most valuable control of subjectivity and a guide to methods of diagnosis and treatment. Without such a control no one is so likely to get into a dangerous rut as the practicing physician. The disclosures of the autopsy will enable him to correct faulty methods, and should effectually check any tendency to superficial diagnosis. Particularly is this the case with regard to such diagnostic methods as palpation, percussion and auscultation. Postmortem percussion offers a most valuable means of acquiring precision in this important branch of physical diagnosis. The percussion boundaries may be marked upon the body by pencil, or long pins may be inserted, so that when the body is opened the exact relation of the percussion area to the organ in question may be noted. In the case of palpable tumors the results of palpation before the body is opened should be carefully controlled by the findings when the actual conditions are exposed. Even when the cause of death seems obvious it is worth while to perform an autopsy at every opportunity offered, both for the sake of controlling technical methods and for the pictures of disease revealed. More accurate knowledge of the nature of the processes of disease can be obtained through one autopsy than through months of textbook reading. To the surgeon the opportunity of examining cases dying after surgical operation should be a source of great satisfaction. The review of anatomic relationships offered by the autopsy is in itself worth while, and in the case of healthy individuals killed by accident the survey of the normal appearances of the organs and tissues offers an opportunity for study too valuable to be neglected. Further, it is justifiable to practice upon the cadaver any surgical operation that does not disfigure it. Removal of the spleen, transplantation of thyroid tissue into the spleen, decapsulation of the kidney, transplantation of ovarian tissue, gastric and intestinal operations, anastomosis of blood-vessels, operations upon the uterus and cervix, prostate, vas deferens, thyroid, nose, ear, etc., and many other surgical procedures may be practiced with profit upon a cadaver during the course of an autopsy. The feasibility of a new operative method or the improvement of an old one may thus be demonstrated.

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