to be examined, and then to tear it completely through in opposite directions with the course of the fibres. This procedure should be continued till the bits become too small to allow further division. <Callout type="important" title="Proper Tissue Division">Divide tissue carefully to avoid missing subtle signs.</Callout> Interstitial inflammation (interstitial myositis) may be either acute or chronic. The acute or purulent form may be either primary — when of traumatic origin it is usually so — or secondary and extended from neighboring parts. For instance, the muscles of the chest may become involved from the pleura, or those of the abdomen from the pelvis, in which latter case, as well as in the muscles of the neck after tracheotomy, gangrene is often superadded. This kind of inflammation never results in the formation of a true abscess, but rather in a purulent infiltration of the muscles, the separate bundles and fibres of which are ensheathed in pus, and are also, äs a rule, the seat of either fatty or hyaline degeneration. Chronic interstitial inflammation, characterized by increase in the interstitial connective tissue and consequent atrophy of the muscular tissue, is associated with and depends on all sorts of chronic changes in neighboring parts — affections of the ribs or of the cervical glands, pleurisy, etc. The muscles thus affected are firm and dense, reddish-gray in color, and present even to the naked eye thick fibrous intermuscular bands. (t?.) Tumors are more common in the muscles of the extremities and will be described in that connection. (e.) It is precisely in the muscles of the neck, the intercostals and the diaphragm that the important parasitic muscular disease — trichinosis — has its favorite seat. In old cases the diagnosis is easy, the cretified capsules appearing as small, oval, white bodies ; and if the animals are very numerous the muscles look as if strewn with fine white sand. The less complete the cretification the more difficult it is to discern the capsules, which are gray in their earlier stages, it is only after the formation of the capsule that the disease can be recognized with the naked eye, though the microscope will reveal its presence in muscle prepared in the manner which we have already described. The search may be facilitated by compressing a bit of the suspected muscle between two glass slides and looking at it by transmitted light. In microscopic examination it is better to use a low power, a higher power being substituted if anything suspicious is found. Trichinee when found in muscle are smaller than when found in the intestines, and have a pointed head and a larger, rounded tail. During the first fourteen days of their sojourn in muscle they lie at full length within the sarcolemma, the contractile substance of which is broken down while the nuclei show signs of commencing growth ; but after this period the animals are coiled up spirally within the sarcolemma, which is considerably thickened, forming a fusiform dilatation. The lumen of the sarcolemma then becomes gradually closed up at either end by progressive cellular growth, and the animal is finally invested in an oval capsule of connective tissue, which increases somewhat in thickness before calcification makes its appearance at the ends. A secondary formation of fatty tissue is often found on either side of old capsules which, when completely creti- fied, must be treated with dilute hydrochloric acid to ren- der the parasites themselves visible. They retain life for years when thus encysted. This fact may readily be demonstrated by opening the capsule by pressure on the cover glass or with needles and freeing the occupant, which may be distinctly seen to move ; its movements can be made more vigorous by warming the microscope. If it be wished to determine microscopically whether trichinas are present or not, it is absolutely necessary to prepare and examine a large number of specimens — twenty or thirty — from different localities, and particularly from the cervical and intercostal muscles and the diaphragm. The specimens should also be as large as is convenient, since the creatures are very irregularly distributed, being sometimes thickly aggregated in one place while another is entirely free from them. It is a matter of experience that they are most numerous near the tendons, and specimens should, therefore, always be taken from such situations if possible. The object of these investigations being usually to determine merely the presence or absence of the parasite, time and labor can be saved by adopting the following method. Bits of muscle the size of a split pea are to be snipped out and coarsely teased on a glass slide in glycerine or dilute caustic alkali ; another glass slide is then to be laid over them, the specimens compressed between the two, and examined rapidly with a low power (fifty to seventy diameters.) (c.) The mammary gland may be laid open and examined from behind without injury to the skin. (a.) General Appearance. The size of the mammary gland in the female varies with the age of the individual, attaining its full development at the age of puberty, and becoming atrophied to a mass of dense and almost pure connective tissue after the menopause. The appearance of the gland is essentially modified during lactation. When at rest it consists chiefly of a very dense and whitish fibrous tissue, scattered about in which at considerable intervals grayish-red nodules of glandular tissue the size of a pin's head may be seen. Toward the termination of pregnancy, and in a still higher degree during lactation, the condition of things is reversed : the gland is increased in size, its general color is grayish-red, and its cut surface has a granular look which reminds one of the salivar}^ glands, except that the granular masses of the breast are rather smaller. It is only near the nipple that much fibrous tissue is to be seen. Numbers of deep yellow, creamy drops exude from the cut surface of the gland when functionally active, either spontaneously or on gentle pressure : these drops somewhat resemble pus but consist solely of colostrum. The microscope shows innumerable fat drops, a variable number of colostrum corpuscles which look not unlike mulberries, on the abundance of which the intensity of the yellow color of the fluid depends, and granular corpuscles with smooth margins and distinct nuclei. (5.) Special Morbid Conditions. 1. In suppurative mastitis^ which is generally limited to circumscribed portions of the gland, the pus may be either infiltrated into the connective tissue between the acini or collected in the form of abscesses. The affection is never the direct cause of death. Sometimes the pus is fetid, as, for instance, after a surgical operation in the vicinity. These abscesses sometimes, though rarely, dry up and leave cavities with cheesy contents. 2. Chronic inflammation (chronic interstitial mastitis) is characterized by an increase in the connective tissue, and is generally confined to small portions of the gland. It may be associated with cystic dilatation of the milk ducts. 3. The female breast is frequently the seat of tumors, so frequently that we shall describe them briefly, although they have generally been removed by the surgeon before the patient comes to the autopsy table. (a.) Carcinoma is the most common as well as most important, and may be divided into three forms according to the relative proportion of stroma and cells. These forms are: hard cancer or scirrhus, soft or medullary cancer, and mucous or colloid cancer, which latter occupies an intermediate position between the other two. The general characters of these forms both to the naked eye and microscopically have been already described, so we shall here confine ourselves to a few details. Cancer of the breast has the peculiarity that its cells (which are very small, especially in the scirrhous variety) are very prone to undergo fatty degeneration ; this is shown by yellow spots, and a reticulated appearance, which has given rise to the term 'reticulated cancer.' The scirrhous variety rarely attains great size. Contraction may take place in the stroma, and thus bring about fatty degeneration and atrophy of the cells (atrophic cancer) and partial arrest of the growth. There is, indeed, no well marked dividing line between the scirrhous and the medullary varieties. The same growth may be scirrhous at its centre and medullary at its periphery ; and secondary formations from a hard cancer may be much softer than the primary growth. Mammary cancer is generally primary and unilateral ; it may, however, be secondarj^, and has been known to be primary in one gland and secondary in its fellow. The outward growth of cancer, toward the skin, has been already described ; its inward growth, toward the pleura, as also the infection of the glands of the axilla, will be considered in another place. ^pitJielioma or cancroid is less common in the breast, and may originate in the external integument (pavement-cell cancer) or in the ducts of the glands (cylindrical-cell cancer). Simple hypertrophy or pure adenoma of the breast is properly classed under cancer, for the reason that transition forms occupying an intermediate position between the two are sometimes found. This form of growth occurs generally in the form of circumscribed nodules, the structure of which is precisely that of alveolar gland tissue. (5.) Sarcoma comes next in importance, and attains a large size oftener than carcinoma. Both varieties occur, the spindle-cell and the round-cell, and often stand in a peculiar relation to the glandular tissue. The cut surface has neither a homogeneous nor yet a fibrous appearance, as is usual in the sarcomata, but looks very like a cross section of a cabbage head, presenting peculiar indented lobe-like masses which are surrounded by fissures or clefts. Cysts which are otherwise scarcely appreciable can be brought to view by extracting these masses. Sections with the double knife show that the more minute resembles the gross structure, in that wart-like or papillary growths project into and distend the ducts. The surface of all these growths is invested with a layer of cylindrical epithelium, a proliferation of that belonging to the ducts. This form of cystic sarcoma or cysto-sarcoma proliferum is very often combined with other forms, and especially with mucous tissue, forming myxosarcoma. (c.) Fibroma also occurs in the breast (cystofibroma^^ though in smaller nodules: it is easily recognized by its toughness and peculiar striated appearance. (c?.) Other tumors are rare, with the exception of hyperplasia of the fatty tissue, which may be either independent or secondary to carcinoma, and particularly the atrophic form of that affection. The axillary lymphatic glands participate so often in affections of the mammary gland, and especially in the carcinomatous affections, that they may be examined now as well as later. They are most easily reached by an incision in the axilla in the direction of the arm, but if one is unwilling to make a fresh incision they can be reached by dissecting the skin off still farther, particularly the skin above the clavicle. When they are the seat of cancer they are more or less enlarged, have lost their normal structure in whole or in part, and yield a milky fluid when compressed. 2. INSPECTION OF THE ABDOMINAL CAVITY. When the examination of the soft parts has been completed the wall should be everted on either side, and the contents thus exposed to view. Unless there is some special reason for examining these first, as in medico-legal cases in which it is suspected that the cause of death may be found in the abdominal cavity, the next step in order is to open the thorax. Before doing this, however, a general inspection of the abdomen should be made with reference to the position and color of the organs, especially in so far as the latter is dependent on congestion or its opposite — and the presence of any abnormal contents noted, inasmuch as the position of ABDOMINAL CAVITY. 97 the organs is modified by opening the thorax, and blood or other fluid is liable to find its way from one cavity to the other. (a.) The Position of the Abdominal Organs. From the fact that the liver and the stomach are the organs which are most liable to undergo changes of position during the progress of the autopsy, they should receive special attention. The left border of the liver reaches nominally into the left hypochondrium, but may extend pathologically far under the left ribs and even beyond the spleen. The relation of the anterior border of the margin of the ribs is very important : it generally coincides with the margin of the ribs, though it very often reaches two to five centimeters below this in the mamillary line. The left lobe of the liver usually covers up the pyloric end of the stomach completely. Pathological changes in the position of the stomach will be spoken of in connection with that organ. The displacements to which the intestine is subject are very numerous and differ greatly in importance. The coils of the small intestine in whole or in part, are specially liable to displacement, being found sometimes in the pelvis and sometimes in either the right or left side of the abdominal cavity. The transverse colon is sometimes depressed in the form of a loop, which may extend even into the pelvis, and the sigmoid flexure may reach to the right side of the abdomen, or, if the mesentery be very long indeed, to the liver. Of far more importance are herniae or ruptures, those malpositions of larger or smaller portions of the intestines, and particularly of the small intestines, which are enclosed in a pouch of peritoneum. The most common form of these is inguinal hernia, generally divided into external or indirect, and internal or direct. In the former the coil of intestine lies in the inguinal canal, in the latter it perforates the abdominal wall. They are more simply distinguished by their anatomical relations to the deep epigastric artery ; the external lying outside of the artery, and the internal inside towards the median line. If the sac of an external inguinal hernia end within the inguinal canal, it is called hernia of the spermatic cord or bubonocele ; if it extend into the scrotum, it is called scrotal hernia ; if the tunica vaginalis remains patent so that the testicle occupies the extremity of the sac, it is called congenital hernia. A hernia may consist of intestine alone, enterocele; of omentum alone, epiplocele; or of both combined, enter o-epiplocele. All the other forms of hernia are much less common. In femoral hernia the sac is contained within the sheath of the femoral vessels, and comes out below Poupart's ligament. We shall content ourselves with simply mentioning the obturator., ischiatic, and umbilical varieties, as well as that which issues through the linea alba and is called epigastric or hypogastric, according as it is seated above or below the umbilicus. In these latter varieties, and particularly in the umbilical, the sac may contain other organs — the liver, for instance. Diaphragmatic hernia., so called, is very often not a true hernia at all, but a mere dislocation of abdominal organs without a peritoneal sac into one or the other pleural cavity. The opening in the diaphragm is generally closed on the right side by the liver, a portion of which may project into the pleural cavity, but if the defect be on the left side, this cavity may contain the stomach and spleen in addition to coils of intestine, etc. Such defects may be either congenital or the result of injury, and the former variety possesses some medico-legal interest, from the fact that children who are the subjects of it generally die almost immediately from suffocation. We now come to a class of malpositions which is of very great importance, and not infrequently proves directly fatal ; we refer to twists and invaginations. Twists — the condition has received the name of volvulus — are chiefly liable to occur in a small intestine with a very long mesentery, and in the sigmoid flexure ; when they occur in the latter, not only is the mesentery apt to be very long, but the two arms of the coils are usually attached near together to the abdominal wall. Invagination or intussusception results when a portion of intestine — generally the small — becomes introverted into a lower portion — generally the large — in such a way that three separate layers of intestine lie one within another. The outer and middle layers have their mucous surfaces, the middle and inner their serous surfaces in apposition. The mesentery is, of course, also carried in with the intestine, and is thus put tightly on the stretch. In recent cases the invagination can be reduced by drawing on the mesentery, but if the condition be of some standing, reduction is prevented by adhesions between the opposed surfaces. It is not every invagination which has pathological significance. In children it is not uncommon to find a single or even several invaginations, the trifling extent of which and the entire absence of any secondary change, even hypersemia, show that they must have taken place during the agony. Their presence shows that violent peristaltic action took place shortly before, and at the time of death. The importance of all these malpositions lies in their tendency to narrow the capacity of
Key Takeaways
- Properly divide muscle tissue for accurate examination.
- Chronic interstitial inflammation can be identified by increased connective tissue and atrophy of muscles.
- Trichinosis can be diagnosed through microscopic examination of muscle samples.
Practical Tips
- Use a low-power microscope to examine muscle samples when searching for trichinae, as they are smaller in muscle than in the intestines.
- Take multiple samples from different areas of the muscle, especially near tendons, to increase the chances of finding trichinae.
- Be aware that trichinae can remain alive and active even after encystment.
Warnings & Risks
- Failing to properly divide tissue can lead to missing subtle signs of disease in muscles.
- Incorrectly identifying or treating tumors can result in misdiagnosis and improper care.
- Invasive procedures like trichinae examination require careful handling to avoid contamination.
Modern Application
While the techniques described in this chapter are rooted in historical practices, they still offer valuable insights into muscle and tumor diagnosis. Modern methods have improved with advanced imaging technologies and non-invasive diagnostic tools, but understanding these foundational principles is crucial for any survival situation where medical resources may be limited.
Frequently Asked Questions
Q: How can trichinosis be diagnosed in muscles?
Trichinosis can be diagnosed by examining muscle samples under a microscope. The parasites appear as small, oval, white bodies that are more easily visible after the formation of capsules. Bits of suspected muscle can be compressed between glass slides and examined with transmitted light to facilitate identification.
Q: What is the significance of trichinae in muscle samples?
Trichinae in muscle samples indicate trichinosis, a parasitic disease that can cause significant health issues. The presence of these parasites can be confirmed through microscopic examination, and they are often found in muscles like those of the neck, intercostals, and diaphragm.
Q: How does chronic inflammation manifest in muscle tissue?
Chronic interstitial inflammation in muscle tissue is characterized by an increase in connective tissue and atrophy of muscular tissue. This condition can result from various chronic changes in neighboring parts, such as pleurisy or affections of the ribs. The affected muscles become firm, dense, reddish-gray in color, and may sh