genesis. It has previously been stated that the more rapidly growing
tumors are those whose cells are most abundant and in the closest and
most {120} intimate relation to blood-vessels. The type of such tumors
is the sarcoma with its scanty intercellular substance, while the
other (histoid) tumors in the same series, as the fibroma, lipoma,
chondroma, etc., are of relatively slow growth. Tumors of the
epithelial series are of slow growth, from the constantly increasing
distance of the new-formed cells from the vascular connective tissue
which provides their nourishment. When, however, the growth of the
epithelium advances into the connective tissue, pushing out in all
directions and coming in contact with new series of vessels, the
opportunities for nutrition are favorable. In like manner, when the
new formation concerns the connective-tissue stroma, as well as the
epithelial sprouts, vascularization proceeds with the development of
the tumor, and favorable conditions for rapid growth are presented.
Large epithelial tumors may thus arise within organs, but, as the
surfaces are reached, the sources of nourishment become farther
removed and the degeneration of the epithelium favors its detachment
and the formation of ulcers. Hence the tumors whose advance is
associated with ulceration belong rather to the epithelial than the
connective-tissue group.
The tendency of the cancerous tumors to become generalized through the
lymphatics, and that of sarcomatous growths through the blood-vessels,
is admitted as an important feature in the differential diagnosis.
Although there are numerous exceptions, the rule is available. Its
explanation is based upon the assumed inability of the larger
epithelial cells of the cancer to pass through the lymph-glands; being
detained, they serve as new centres of growth. The smaller cells of
the sarcoma, on the contrary, are permitted a passage through the
gland. The numerous and thin walled blood-vessels present in the
rapidly growing sarcoma permit an extension of the latter into their
interior, and thus a ready opportunity is offered for the formation of
emboli.
Another important modification in the classification of tumors has
resulted from the recent discoveries regarding the nature and effects
of infective agencies. Virchow grouped together under the term
granulomata certain growths composed of granulation-tissue occurring
in syphilis, lupus, leprosy, and glanders. Their relation to
inflammatory processes was very intimate, yet they were recognizable
as tumors from their possession of many of the characteristics
generally admitted as belonging to such morbid growths. Although at
times their presence might be regarded as evidence of an inflammatory
disturbance, their frequent appearance independently of general
symptoms of the latter was apparent. These tumors, furthermore, were
so frequently accompanied by inflammatory products as to suggest a
like cause for both. Virchow stated that the recognition of the
etiology of these tumors was indispensable to their separate
consideration, and laid stress upon the presence of a specific virus,
contagious and infectious, in the case of syphilis. His views
concerning the etiology of leprosy, though more guarded, yet carried
the suggestion of the importance of exact investigation concerning the
assumed contagious character of this disease. The contagiousness of
glanders was not only admitted, but the similarity of its manner of
origin and propagation to the invasion of syphilis was also stated.
Not only were the resemblances between glanders and syphilis
recognized, but lupus, leprosy, tubercle, and scrofula were also
admitted as presenting a similar relation.
{121} The importance of recognizing the etiology of these tumors
rather than their anatomy as a basis of classification was strongly
urged by Klebs,[88] who proposed the term infective tumors for the
group of granulomata, including syphilis, lupus, leprosy, and
glanders; and for tubercle, scrofula and the pearly distemper of
animals, which Virchow had classified as lymphomata. This group has
been still further extended by the addition of the lymphomata
occurring in typhoid fever, scarlet fever, and diphtheria. Ponfick[89]
has recently added the disease actinomycosis to the series, and
Cohnheim suggests that certain of the lympho-sarcomata may be
similarly classified.
[Footnote 88: _Prager Vierteljahrschrift_, 1875, cxxvi. 116.]
[Footnote 89: _Die Actinomykose des Menschen_, 1882.]
The growths thus included have a common element of structure--the
granulation-tissue, with its possible disappearance through absorption
or its transformation into an abscess or dense fibrous tissue. Such
features are those common to the granulation-tissue resulting from
ordinary inflammation. Their essential characteristic, however, lies
in the etiology of this granulation-tissue, and for many members of
the group the cause has been discovered to be microscopic organisms.
The constant presence of these is determined in sufficient numbers, in
such distribution, and in such relation, as to explain the nature and
occurrence of the tumors.
The evidence recorded is not equally full and exact for all members of
this group. Neisser[90] has discovered the bacillus of leprosy, and
the discovery by Koch[91] of the bacillus of tuberculosis, scrofula,
and pearly distemper has already been referred to. Schütz and
Löffler[92] have lately announced their isolation of the
micro-organism causing glanders, and Bollinger[93] discovered the
fungus whose presence is necessary for the existence of actinomycosis.
[Footnote 90: _Virchow's Archiv_, 1881, lxxxiv. 514.]
[Footnote 91: See page 99.]
[Footnote 92: _Deutsche medicinische Wochenschrift_, 1882, lii. 707.]
[Footnote 93: _Centralblatt für die med. Wissenschaften_, 1877,
xxvii.]
In the above affections the organisms are to be regarded as the
characteristic active agent in producing the phenomena of the disease
in which they occur. The presence of micro-organisms in syphilis,
typhoid fever, scarlet fever, and diphtheria is admitted, yet their
absolute identification and constant presence as a cause of the
various manifestations of the respective diseases still remains to be
proved.
The classification of tumors herewith presented is essentially that of
Virchow, with such extensions and modifications as have arisen in
consequence of the investigations and discoveries during the twenty
years which have elapsed since the delivery of his memorable series of
lectures. Cysts are mentioned, as well as growths, from the importance
of the former in practical medicine. The frequent simultaneous
occurrence of cysts and growths in the same tumor should be mentioned,
and the cystic feature is usually indicated as a qualification.
CYSTS.
Cavities, either new formed or pre-existing, with various contents.
The latter are blood, liquid other than blood, and gland-secretion or
retained secretion. The wall varies in structure in accordance with
the method of origin of the cavity.
{122} _Hæmatoma._
A collection of extravasated blood, usually within the tissues.
Examples, hæmatoma of the pericranium (periosteum), of the external
ear, muscle, dura mater, ovary, broad ligament, vulva, anus, uterus
(from retained placenta), hæmatocele, dissecting aneurism.
_Hygroma._
A collection of transuded or exuded fluid in pre-existing or
new-formed spaces. Examples, hydrocele, hydromeningocele,
hydromyelocele, hydrencephalocele, ganglion, inflamed bursa.
_Retention-Cyst._
An accumulation of retained secretion in follicles or canals from
obstruction to its escape. Examples, atheroma and comedo of the skin,
mucous cysts of the gastro-intestinal mucous membrane, ovula Nabothi,
and cystic polypus of the uterus; retention-cyst of the antrum,
vermiform appendage, gall-bladder, and bile-ducts; dropsical
dilatation of the ovarian follicles, Fallopian tube, uterus
(hydrometra), parovarium (cyst of the broad ligament); hydronephrosis
and multilocular cystic kidney, spermatocele, ranula, galactocele.
* * * * *
The growths are classified according to the tissues of which they are
chiefly composed and from which they originate, and according to their
etiology. There are consequently the connective-tissue group; that of
tissues of higher function, as muscle, nerve, and vessels; and the
epithelial group, in which the new formation of epithelium is the
essential feature. The teratoid group comprises a more complex massing
of tissues, representing a combination of those derived from all the
germinal layers of the embryo. The infective group includes those
tumors whose structure is closely allied to that of the products of
inflammation, but whose origin is the direct result of the
introduction from without of a microphyte.
CONNECTIVE-TISSUE GROUP.
Each member mainly composed of a more or less typical growth of a
connective tissue:
Myxoma,
Lipoma,
Glioma,
Chondroma,
Fibroma (including papilloma and melanoma),
Osteoma.
To these are added tumors composed of an atypical growth of a
connective tissue, chiefly manifested by a predominance of cells:
Endothelioma,
Sarcoma.
The sarcoma includes as many varieties as there are tissues in this
group, hence,
Myxosarcoma,
Liposarcoma,
Gliosarcoma,
Chondrosarcoma,
Fibrosarcoma, melanosarcoma,
Osteosarcoma.
{123} GROUP OF TISSUES OF HIGHER FUNCTION.
Myoma, of striped (rhabdomyoma) and smooth (leiomyoma) muscular
tissue,
Neuroma, of nerve tissue,
Angioma, of blood-vessels,
Lymphangioma, of lymphatics,
Lymphoma (?), of lymph-gland tissue.
EPITHELIAL GROUP.
Epidermis:
Callus,
Corn,
Keratosis,
Horn,
Onychoma.
Epithelium of mucous membranes or glands:
Struma (?),
Adenoma,
Cystoma.
In the above varieties the growth of epithelium is more or less
typical, a simple hyperplasia, either alone or combined with the new
formation of fibrous tissue. Only the last three members of the series
are tumors in the limited sense.
CANCER.
Cancer remains as an epithelial tumor, representing the atypical
growth of cells resembling epidermis or the epithelium of glands and
mucous membranes, extending into parts where epithelium is not found
as a normal constituent. A new formation of connective tissue is
usually associated with that of the epithelial cells.
Numerous varieties of cancer are described, according to the physical
and structural peculiarities of the tumor. The scirrhus and
encephaloid of the earlier writers are now transformed into fibrous
and medullary cancer. This change in name is due to the stress laid
upon the predominance of the fibrous stroma as the usual cause for the
hard, dense, scirrhous cancer, while an abundance of epithelioid cells
in relatively large alveoli is present in the encephaloid,
marrow-like, medullary variety.
When the growth takes place from the skin or mucous membranes, the
surface frequently presents numerous and usually arborescent papillæ
or villi. The papillary cancers of the skin and the villous cancers of
mucous membranes are thus distinguished.
Cancerous growths of the skin and transitional membranes, often called
epithelioma or cancroid, usually contain epithelioid cells resembling
epidermis, and are therefore designated as epidermoid or
pavement-celled cancer. The alveolar contents of certain cutaneous
cancers are cells resembling those of the deeper layers of the rete
mucosum, while those of other cancers of the skin resemble rather the
epithelium of sweat-glands. Growths of the former character extend
laterally, ulcerate early, and are known as superficial cutaneous
cancer. They form one of the varieties of the so-called rodent ulcer.
Cutaneous cancers, simulating in their structure a reproduction of the
epithelium of sweat-glands, represent a variety of glandular cancer.
The latter term is applied to cancerous growths which arise in
glandular organs, with suggested resemblances of their cells to the
gland-cells of the respective organ. {124} Cylindrical-celled cancer
is frequently met with in those parts of which a cylindrical
epithelium is a normal constituent.
The degenerations of the epithelioid cells and stroma suggest
qualifying terms. The mucous and colloid cancers are those whose
alveolar contents or stroma have undergone a mucous or colloid
degeneration. The keratoid cancer is one which presents the horn-like
transformation of its epidermoid cells. The melanotic cancer contains
abundant pigment, melanin, within its cells.
These differences in the structure and appearance of the tumor are
frequently associated with certain modifications of growth and
clinical properties. The epidermoid cancers are less likely to recur
after early removal; the medullary cancers are of rapid growth and
prone to ulceration; while the fibrous or scirrhous forms are of
extreme slowness of growth. In general, however, the pathological
importance of cancerous tumors is essentially the same wherever the
seat and whatever the peculiarities of structure.
TERATOID GROUP.
Includes those tumors, usually of congenital origin and apparent at
birth, composed of connective tissue, epithelium, nerves, muscle, and
vessels. These tissues are often so grouped together as to suggest
systems of the body and parts of an individual. Cysts are often
present which simulate cavities found in the body, whether of normal
or pathological origin.
In this group are the dermoid cysts with their various contents,
epidermis, sebum, hair, teeth, and bone. The solid teratomata, with
all varieties of connective tissue, as fibrous tissue, fat tissue,
cartilage, bone, neuroglia, in addition to nerves, muscle, and
vessels. Squamous, cylindrical, and ciliated epithelium may be present
and line cavities, at times tubular, whose walls are formed of skin or
mucous membrane. Other tumors of this group are commonly included
under monstrosities, and comprise the varieties of duplication of
parts of the body, of which the extreme instances are such double
monstrosities as the Siamese Twins, Ritta and Christina, the Spanish
Cavalier, and the like.
INFECTIVE GROUP.
The chief characteristic is the cause, micro-organisms, which,
introduced into the body, produce, through their dissemination and
development, multiple growths of tissue like those resulting from
persistent inflammation. As their structure corresponds with the
productive results of inflammation, and their cause is analogous to
the infective causes of inflammation, these morbid growths are closely
allied to inflammatory disturbances. Their classification among tumors
is desirable, as they represent circumscribed growths whose
appearance, persistence, and effects closely resemble those
characteristics of the morbid growths, in the limited sense, in which
the new formation of tissue occupies a wider range:
_Granuloma_ of tuberculosis, scrofula, leprosy, glanders,
actinomycosis, syphilis, lupus.
_Lymphoma_ of diphtheria, scarlet fever, typhoid fever.
{125}
GENERAL ETIOLOGY, MEDICAL DIAGNOSIS, AND PROGNOSIS.
BY HENRY HARTSHORNE, M.D.
ETIOLOGY.
Recognizing pathology as simply morbid physiology--that is, the study
of the body and its functions in states of disorder from morbid
conditions--how these morbid conditions are produced is the complex
question to be answered by Etiology.
Nor is this question (or series of questions) by any means only of
speculative or theoretical importance. It is, indeed, eminently
practical. What a difference, for example, there must be in the
diagnosis, prognosis, and treatment of an attack of inflammation of
the eye, in accordance with its causation by ordinary conditional
influences (taking cold), by a particle of steel imbedded in the
cornea, or by syphilis! How great the difference between the wound
made by the teeth of an animal, in one case with, and in another
without, the presence of rabies in its system! Take the instance of
what we call fever: at a certain stage it is almost the same in half a
dozen diseases. By the causation, when known, of this common congeries
of symptoms we judge of the essential nature of the malady, and so of
its proper treatment.
It is a maxim in philosophy that every event or effect must have at
least two causes. In medical etiology we often find many causes
conspiring to produce one effect. These may be, and commonly have
been, grouped together under two heads; as, 1, predisposing, and 2,
exciting, causes. But under each of these may come a number of
agencies contributing toward the production or modification of
disease. Thus, of predisposing causes we may enumerate inherited
constitution, habits of life, previous attacks of disease, atmosphere,
and other immediate surroundings. Exciting causes--say, of an attack
of apoplexy--may be, in the same case, mental shock, a stooping
posture, an over-heated room, etc. One disease is very often the next
preceding cause of another. So we speak of the great class of sequelæ
of acute or subacute disorders; as, ophthalmia after measles, deafness
following scarlet fever, or blindness small-pox, abscesses following
typhoid fever, paralysis diphtheria, etc. But this kind of causation
is extremely common also in chronic affections. What a train of
organic troubles, of kidneys, heart, arteries, brain, and other parts,
attend the affection to which we give the name of Bright's disease!
How complex the sequence often of valvular disease of the heart,
itself in many instances the effect of rheumatic fever, with {126}
endocarditis as a local manifestation of that disorder! Hardly any
discovery in pathology (or pathogeny, the generation of diseases) of
the last half century has been more remarkable and fruitful than that
of thrombosis and embolism, with their serious and not rarely fatal
consequences, through obstruction of the blood-supply to different
organs.
Previous diseases constitute an often overlooked class of factors in
predisposing to new attacks, and also in determining their course and
results. Of some affections one attack prepares the way for another,
as is the case with intermittent fever, convulsions, delirium tremens,
and insanity. Just the reverse is true of yellow fever and of all the
exanthemata, as scarlet fever, measles, small-pox; likewise of the
analogous disorders, mumps and whooping cough. The moot question in
this regard concerning syphilis may be left for discussion elsewhere.
Our classification of the causes of disease may be set forth in simple
form, thus:
1. Pre-natal causation--viz. hereditary transmission of a proclivity
to certain disorders, and also the influence of circumstances acting
on either parent at the time of conception or on the mother during
gestation.
2. Conditional causation--_i.e._ that belonging to variations of
temperature, humidity, etc., affecting individuals.
3. Functional causation--that which is connected with excessive,
deficient, or abnormal exercise of any of the functions of the
economy.
4. Ingestive causation--_e.g._ bad diet, intemperance, poisoning.
5. Enthetic causation--viz. that of all contagious, endemic, and
epidemic diseases. Closely allied to this is epithelic morbid
influence--namely, that of the parasites producing certain affections
of the skin, as itch, favus, etc.
6. Mechanical causation. The effects of this belong chiefly, though
not exclusively, to the domain of surgery.
Pre-natal causation is of immense consequence, and its study takes in
the whole scope of the influences of species, race, family, and
individual parentage. Darwin's observations and speculations, and
those of other evolutionists, have not ignored the field of human life
in considering the struggle for existence and the survival of the
fittest. If we are obliged to admit that such a struggle and survival
do exist for men as well as for animals and for plants, it is
nevertheless obvious that either man's reason and will introduce
exceptions to the ordinary laws of development and selection in
nature, or else a very peculiar standard of fitness must be recognized
in the survivals of humanity. Many feeble, inert, deformed, and
diseased forms survive and perpetuate offspring through a long series
of generations, while strong and admirable ones perish, often even
destroying each other.
Leaving this theme, upon which biological science has not yet
pronounced its last word, we may inquire, What diseases are reasonably
ascribed to hereditary transmission? First, it must be remarked that
seldom is a disease actually received directly from a parent. Putting
aside a few asserted instances of variola and allied or analogous
affections in utero, congenital constitutional syphilis and (more
rarely) scrofulosis seem to afford almost the only examples of this.
Nearly always it is a predisposition merely that is inherited. This,
however, may be very strongly marked. Its seat is evidently in that
(as yet) occult law or {127} process of individual organic development
to whose manifestation we give the name of the constitution. In some
families all the men grow bald before forty; in others, scarcely so at
eighty. Some may expect deafness in middle life, others blindness in
old age, and others, again, have a probability of death from disease
of the heart at about fifty or apoplexy at about sixty years of age.
Such considerations enter into every examination for life insurance,
and they are no less important in our prognostications of the results
of diseases in practice.
Speaking more definitely, gout is undoubtedly often hereditary. That
is, a healthy childhood may be followed by liability to gout in adult
or middle age, even in the absence of direct provocatives to that
disorder, but much more frequently when they are present. Gout affords
an example of the general fact that inherited proclivity to special
diseases shows itself at nearly the same time of life in each
generation--scrofula in childhood, phthisis in adolescence or early
maturity, gout from thirty to forty, apoplexy after sixty, etc. But
exceptions to such rules are not at all rare. Gout also exemplifies
another important fact--viz. the occasional modification of the
transmitted morbid tendency or "diathesis." Parents who have regular
gout--_i.e._ painful attacks of acute inflammation of the smaller
joints, followed by deposits of urates, carbonates, etc.--not
unfrequently have children who are subject to neuralgia or dyspepsia
or modified rheumatic attacks (not sufficiently recognized in
practical treatises), to which the name "gouty rheumatism" is most
applicable. Again, in one generation there may be a marked tendency to
insanity; in the next, to paralysis; in a third, to tubercular
meningitis during infancy.[1] Or some of these successions may occur
in a reverse order.
[Footnote 1: For example, in one family known to me the grandmother
had paralysis, the mother died insane, and her three children all died
of tubercular meningitis.]
Constitutional syphilis is undoubtedly often conveyed by inheritance
from either parent. Sometimes the impression of this diathesis is so
intense as to devitalize the foetus in utero, causing still-birth. Or
the manifestations of the disease occur early in infancy, with
symptoms like those of the secondary or tertiary affection in the
original subject of it. Not often, indeed, is the exhibition, in some
manner, of inherited constitutional syphilis delayed beyond the time
of childhood.