for the student and the practitioner, to contemplate steadily the great characteristics of cancerous disease, than to load his memory with details of the incidental and trivial. Partly on this account we have not attempted to give any very minute description of the structure of cancerous tumors, for our own examinations have most thoroughly convinced us of the non-existence of any special structural character, absolutely and in all cases distinctive of cancer. This point, which is in accordance with the teaching of the best authorities, seems far from being correctly understood in the present day, and we cannot but think that there is still much tendency to over-estimate the microscope as a means for the diagnosis of cancer. It is our opinion that the cases are very rare indeed, where the microscope will avail to detect cancer with any certainty, where the naked eye features are insufficient. On the other hand, we have more than once seen unquestionable cancers made up of substance which we should have been led, from microscopic examination alone, to consider as of a simple nature. What may be said relative to the distinguishing of cancerous from other tumors, by their mere physical characters, and not by their living actions, amounts to this: If a tumor, on being incised and compressed, yield a whitish, milky juice, (the socalled "suc cancereux,") it is probably malignant; we have, however, failed to obtain this sign from actual encephaloid. If the cell-growth of a tumor is what may be called exceedingly multiform, i. e. one particle unlike another, the field of view being filled with other varieties of shape and construction, there arises a strong presumption that the structure is malignant. If a tumor consist of an abundant cell-growth lying in a basis substance of slight consistence, and containing very little fibre, it so far bears a close resemblance to encephaloid. If, on the other hand, a tumor consist chiefly of fibre or fibrillating blastema, the presumption of its cancerousness diminishes; we have, however, seen a growth in the liver, which had all the aspect of a scirrhous formation, and probably was so, which yet consisted solely of fibre-forming solid blastema. If a tumor infiltrate adjacent parts, it is probably malignant, but all cancers have not this character. The presence of large cells, containing several nuclei, similar to those figured by Lebert' and Bennett,2 would be a strong argument for the cancerous nature of the tumor, from whence they proceeded. So also we should regard the development of a nucleus into a large granulous globule or vesicle, or into any structure very dissimilar to its original condition, or that of the nuclei of natural tissues. In concluding these general remarks, we may state, we think, the following position with some confidence, viz: that, starting from encephaloid as the representative of cancer par excellence, we find the cancerous-character gradually declining as we pass through a series of formations, such as we have above described, until we come to those of whose innocent nature there is no question. The exact limit, we believe, at which cancerousness is lost, cannot be marked by any characters of a growth itself. The vessels of cancer, for the most part, we believe, are of the ordinary kind, derived from those of the natural tissues by the process Phys. Patholog. Pl. xxi. fig. 5. 2 On Cancerous and Cancroid Growth. Figs. 69 and 117. of extension or growth; sometimes, however, it seems that blood and vessels are formed in the blastema of a tumor, as we have described them to be in exudation matter; this we consider is most likely to be the case in growths of the hæmatoid character. The blood contained. in the developing vessels is seen, as it is said, to oscillate in them before they have anastomosed with those of the general system. No special formation of lymphatic vessels or nerves, seems to take place in cancerous tumors. The lymphatic vessels of the part affected, no doubt, act as absorbents of the redundant blastema, as is amply shown by the special contamination of the glands, to which those vessels immediately proceed. The nervous filaments traversing or distributed to the part which is the seat of the cancerous growth, are often involved in the mass, and becoming injuriously pressed on, or otherwise injured, occasion the most frightful pains. There is scarce anything accurately determined, respecting the chemical composition of cancer. Encephaloid is said to consist chiefly, if not entirely, of albuminous matter; Scirrhus to contain gelatin also, while colloid jelly seems to be a principle quite sui generis. Possibly, there may be some special cancerous virus, as there is a variolous and syphilitic, but as yet chemistry knows nothing of it, and we only infer their existence from the effects they produce. [The subject of cancer and its microscopic diagnosis being one of deep interest, we present here the illustrations of cancerous structure from the valuable paper of Dr. Francis Donaldson, of Baltimore, Maryland. See Am. Journ. of Med. Sci., vol. xxv. p. 43. "It is improper," remarks Dr. D., "to attempt to divide cancer into so many species, as they all have the same common pathology. The variety of aspect, consistence, volume, coloration, and vascularity, is caused merely by the amount of fibrous element, of fat, or of gelatinous fluid present; all of which are purely accidental, and in no way essential to constitute the growth. The density, softness, &c., may also vary according to the organ involved; the breast and the pylorus take generally the form of scirrhus; whereas the bladder, the kidneys, &c., are more likely to be affected with encephaloid. Compare the physical characters of cancer with those of the simple tissues, such as the muscular, areolar, dartoric, osseous, &c., or with those of the compound, as the glandular, the synovial, the mucous, &c., and the difference will be very apparent. Its greater or less firmness, its homogeneous fibrous aspect with its lactescent infiltrated juice, are very characteristic. The presence of this peculiar fluid is of itself a point of differential diagnosis of great value; the microscope always detecting in it, when found, the presence of cancercells, &c. No matter what organ is the seat of the disease, this fluid can generally be scraped from the cut surface, or squeezed out by gentle pressure. It is particularly abundant in encephaloid, and frequently oozes out in drops having a white cloudy appearance of the consistence of cream, and very much of its color, being slightly tinged with yellow. It may sometimes, on superficial inspection, be confounded with lightcolored pus, which has, however, with the yellow, a slightly greenish tinge. If, from the conditions of its formation, there can be any doubt,. an appeal to the microscope will at once settle it by giving us the characteristic pus-globule. (See Figs. 99 and 100.) "The cancer juice forms readily an emulsion with water, and in this differs from tubercular matter and from that pressed from sebaceous tumors. The color of this juice is of course modified by the mixture of other fluids with it; thus, when the vascularity is great, it is often reddish; when from a deposit of dark pigment, we have what is called melanotic cancer, it becomes of a dark brown. When mixed with much fat, it is more consistent; in colloid, it is thicker and sometimes grumous. "In the accompanying figures, we have," says Dr. D., "attempted to arrange (under several divisions), into groups, the different forms of the cancer-cell we have met with. In making the selection from the numerous drawings we have collected in our album, we have thought it better, instead of giving only the types, so to speak, of the several shapes under which we desired to include all the various modifications, to show as many as possible of the numerous varieties. For the rudeness of the designs themselves we ought, perhaps, to apologize, but they are, as far as we could make them, exact representations of what we saw in the field of the instrument. We will first describe the proper elements separately, and then speak of the objections offered by Dr. Bennett, and some others, to their distinct characters as pathognomonic of cancer, giving drawings of other elements confounded with them. The points of dissimilarity we will call attention to with a view of fixing the differential diagnosis. The mode we have employed has been simply to place between two pieces of glass a drop of the juice, obtained either from gentle pressure, or by scraping the cut surface with a scalpel, diluted with a little water. The cutting off of small slices with Valentin's knife, and examining the whole mass together, will exhibit, almost invariably, more or less fibrous structure, but necessarily the lens em ployed must be much feebler, and the cell is not seen to the same advantage; moreover, the fibrous element is purely accidental, and is found in a vast number of tumors. The instrument used is a first-class one, manufactured by Nachet. The power we have habitually used in studying cancer element has been one of 555 diameters (Nachet's No. 6). Mr. Bennett used, in his researches, one of 250, which he recommends to others. We state this for the purpose of explaining why it is he has omitted some characters of the element which we believe are of great importance. The element of cancer consists of three parts, cell, nucleus, and nucleolus, all of which are peculiar to it. We will consider "1. The cancer nucleus, as inclosed in a cell, or as floating free by itself. "2. The polygonal, or more or less spherical and ovoid cell. "3. The caudated cell. "4. The fusiform cell. "6. The compound, or mother cell. "7. Agglomerated nuclei connected by amorphous tissue. "In all the varieties of cancerous tissue, nuclei are to be found either enveloped by a cell, or floating free, generally more or less of both; in some specimens, there exists a large number of free nuclei with only an occasional cell. The form and appearance of these nuclei is the most constant and unvarying of all cancer elements. They are, Fig. 91, a, ovoid, or more or less round; the latter are found more particularly when the eye or the lymphatic glands are the organs diseased. Some Fig. 91. Free cancer nuclei. a. Type form. b. The same, with a piece nicked out of the side accidentally. c. Shows a free nucleus, in which the molecular granules are very minute, often met with in perfectly fresh specimens. d. A nucleus, in which larger granules have commenced to form. e. The characteristic nucleolus with its dark contour and bright centre. h. Fine molecular granules. i. The second variety of granules, or gray granulations. j. Fat granules. times (as in b), we find little pieces of the wall of the nuclei apparently nicked out; but evidently it is purely accidental, and the proper shape can easily be recognized. They have, ordinarily, in width, a diameter of from 1-100th of a millimetre, or (a millimetre being equal to .039th of an inch) of .0039th of an inch, to 1-66th of a millimetre, in one instance we met with one as wide as 1-38th of a millimetre; in length they measure from 1-133d to 1-100th of a millimetre. Their contour is dark and well defined, with the interior containing very minute dark granulations; indeed, when the specimen is perfectly fresh, they have a homogeneous aspect, the granulations being so small as to give the appearance of a mere shading (as in c); if the specimen is kept a day or two, we find the interior filling up with larger granulations (as in d). Within these nuclei, when they have not been obscured by granular or fatty degeneration, there is found habitually a small body, or nucleolus, averaging in diameter about 1-500th of a millimetre. These nucleoli have somewhat of a yellowish tinge, with a brilliant centre and dark borders, refracting light like the fat-vesicles. We would call attention, particularly, to the peculiar brilliancy of the centres of these nucleoli, which, we think, is characteristic; it can be almost invariably noticed, if the focus is varied. Their large size, in proportion to the nuclei, should also be noticed, together with the great variableness of their position, sometimes being near the centre, and again in close contact with the walls (see e). Ordinarily, in other elements, they are found almost constantly in the centre. Very frequently, two or three nucleoli are found within the same nucleus. M. Robin' mentions the action of acetic acid upon cancer nuclei and their nucleoli, as differing from that on other elements, particularly epithelial; it renders the nucleus gradually paler, together with the cell, destroying neither-but MS. notes of his Cours de Histologie, 1850. the nucleolus is perfectly untouched by it; whereas in epithelial cells, where generally in those of the skin the nucleoli are wanting, the action of acetic acid destroys the cell, leaving the nucleus unaltered." "It is of primary importance for the proper examination of the cancer nucleoli that the specimen should be fresh. Such being the case, we do not remember ever having found these peculiarities wanting." "We have examined some specimens in which free nuclei were in great abundance, and where, after long-continued diligent search, we were unable to discover any cells. More particularly is this the case in cancer of the liver, of the pylorus, and of the lymphatic glands; more rarely in that of the eye. In the breast, many full-formed cells are found with more or less of free nuclei floating in the blastemic fluid. It may be well to remark here that we find also free nuclei of fibro-plastic and epithelial cells, of the finest bronchial ramifications, each with their peculiarities. Mr. Bennett appears to us to have confounded them all together in speaking of what he calls fibro-nucleated tissue. "In regard to the cells themselves of cancer, although we stated their forms as very variable, yet many of them are modifications of the polygonal, which may be considered the type. In explanation of the theory of the shape and size of various cell-membranes, we would refer the reader to Professor Schwann's views;' undoubtedly, as he supposes, the close crowding together, and the processes of endosmose and exosmose, may be the producing cause. Thus, we observe that in hard firm tumors, particularly those of the breast and ovaries, the cells found are exceedingly irregular, sometimes nearly triangular, Fig. 92, f. The ovoid or spherical are more frequently met with in soft or medullary cancer, Fig. 92, g, where there is but little pressure, although its juice appears often to be but one mass of cells. It is rare, however, that perfectly round cells are met with, but very generally the angles are well rounded in those which appear to be derived directly from the polygonal form, the diameter of which is very variable, ordinarily from th to th of a millimetre. One peculiarity of this, as of the other forms of cancer-cell, is the presence of the granulations of different sizes in their interior; whereas, in epithelial cells, the interior is generally, when fresh, of course, homogeneous. In cancer, we find the three varieties of granulations given by M. Robin; first, the very fine black dots found in all organic elements, and named by the French, very appropriately, poussière organique; secondly, the gray granulations, a form somewhat larger; and, lastly, the fat granulations distinguished by the refraction of the light. This first variety of cells contains nuclei, having in their interior invariably one or more nucleoli, both of which retain the characteristic points described above. The large size of the nucleus, in proportion to the diameter of its cell, will at once strike the eye of the careful observer. The variable position, also, of the nucleus within the inclosure, appears to us to be peculiar to cancer; in cells of other structures, the rule is to find the nucleus very nearly in the centre, except with fibro-plastic cells, where the nuclei appear to have a peculiar affinity "Microscopical Researches into the Accordance in the Structure and Growth of Animals and Plants," by Th. Schwann. Sydenham Soc. edit. 2 Tableaux de Anatomie, &c., par Ch. Robin. Paris, 1851. |