great obscurity. Older writers, who were accustomed to reach their
conclusions in great measure through the observation of symptoms alone,
were obliged in the absence of anything like correct knowledge of
anatomy, physiology, and pathology to supply from the imagination most
of their theories of disease. Untrammelled by the bonds of accurate
investigation and ignorant of pathological anatomy, they found no
difficulty in ascribing to various parts and organs peculiar groups of
symptoms, both physical and moral; and for a number of these the spleen
was held responsible. We now know that many of the symptoms thus
supposed to indicate splenic disease depend upon alterations in other
parts of the body, and may be observed in persons possessing perfectly
healthy spleens. But while we have learned that symptoms formerly
supposed to depend upon splenic disorder may, in reality, have nothing
to do with this organ, we still remain ignorant of many of the real
symptoms of splenic disease, as well as of many of the morbid
conditions that induce them. Such knowledge as we have, however, is
based upon comparisons of symptomatology with dead-house revelations
and the experience of the laboratory, and, while as yet imperfect,
cannot fail to increase under modern methods of research.
In order to begin the study of diseases of the spleen in an intelligent
manner it is manifestly necessary to have some settled ideas regarding
its anatomy and physiology. No apology is needed, therefore, for the
brief anatomical and physiological descriptions that follow.
The spleen is the largest of the ductless glands, and is situated in
the left hypochondriac region. It is of a dark slate or bluish-gray
color, and often of wrinkled appearance. It is of soft, friable
structure. It rests between the stomach, diaphragm, and left kidney,
and in form resembles a flattened oval. It extends from the level of
the eleventh rib, beginning one or two centimeters distant from the
vertebral column, downward and forward to a position about four
centimeters from the point of the eleventh rib (Lushka). It is
separated from the ninth, tenth, and eleventh ribs by the diaphragm. It
presents two surfaces--one external and convex, facing the diaphragm;
the other internal and concave, applied to the cardiac end of the
stomach. The hilum divides the internal portion into two parts by a
deep fissure, which marks the line of attachment of the gastro-splenic
omentum. The larger and anterior part is bound to the fundus of the
stomach by delicate areolar tissue, and the posterior and smaller
portion to the left pillar of the diaphragm and the left suprarenal
capsule. The upper portion is connected with the diaphragm by
peritoneum forming a suspensory ligament. The bottom of the hilum is
perforated by a number of openings for the transmission of
blood-vessels, nerves, and lymphatics. The anterior border of the organ
is notched and thinner than the posterior border. The pointed lower end
touches the splenic flexure of the transverse colon and rests upon the
costo-colic ligament. {952} The spleen varies in size and weight within
wide limits. Its average weight in adults is 250 grams, its length from
11 to 13 centimeters, and its thickness from 4 to 6 centimeters (Orth).
Its volume is from 150 to 180 cubic centimeters. According to Gray, the
proportionate weight of this organ to that of the whole body varies
from 1:320 to 1:400, gradually diminishing until old age, when the
proportion becomes as 1:700.
In the vicinity of the spleen are often found a number of small bodies
similar to it in structure. These are known as accessory spleens, and
are usually situated in the gastro-splenic or in the greater omentum.
The attachments of the viscus are not very close, and much variation in
size and position is possible.
Except at the hilum the peritoneum forms everywhere one of the
coverings of the spleen. Its peculiar sheath or capsule is composed of
fibro-elastic tissue of a whitish color, prolongations of which extend
into the substance of the organ and form the trabeculæ that constitute
its supporting framework and sheaths for blood-vessels and nerves. A
close meshwork is thus created in which are contained the splenic
vessels and pulp. This fibrous coat and these trabeculæ contain
involuntary muscular fibres. These, with the elastic fibres, provide
for the changes in size that the organ undergoes. When incised, the
normal spleen presents a reddish-brown color, and its substance may be
readily broken down with the finger into a pulp. This pulp consists of
a mass of branched intercommunicating connective-tissue corpuscles of
different sizes, within the substance of which remains of red
blood-corpuscles may often be detected. The interstices of these cells
are filled with blood. The very large splenic artery enters the spleen
by numerous branches, ramifying within the trabecular sheaths and
terminating in pencils of minute size.
The external coats of the smaller arteries are converted into lymphoid
tissue, which, suddenly expanding here and there, forms the bodies
known as the Malpighian follicles, which are supplied with capillary
vessels, and which may often be distinguished by the naked eye as
points of whitish color, sometimes attaining the size of pinheads.
These small arteries end in capillaries, which, according to Müller,
gradually lose their cylindrical character and emerge into a system of
connective-tissue corpuscles, inosculating with the corpuscles of the
splenic pulp in such a manner that the blood passes into the
pulp-tissue freely, and is gradually brought to the veins by the
transition of this tissue into that of the blood-vascular system. The
splenic lymphatics originate in the arterial sheaths and in the
trabeculæ. In the former case they accompany the blood-vessels; in the
latter, they communicate with a superficial network in the corpuscle.
All join at the hilum and enter the neighboring lymphatic glands. The
splenic nerves are from the right and left semi-lunar ganglions and
right pneumogastric nerve. They accompany the branches of the splenic
artery, and have been traced deeply into the tissue of the organ.
It is perfectly established that under normal conditions the volume of
the spleen may vary considerably, and especially during the act of
digestion, and that this does not occur through simple engorgement of
the vessels. The very important experiments of Roy show that, in cats
and dogs at least, the splenic circulation does not depend upon the
ordinary blood-pressure, but is carried on "chiefly, if not
exclusively, by a rhythmic contraction of the muscles contained in the
capsule and trabeculæ of the organ."[1] This rhythmic contraction and
expansion Roy observed to occur with great regularity at the rate of
about sixty contractions an hour, with extremes of rapidity of rhythm
of forty-six seconds for the most rapid and two minutes three seconds
for the slowest. He also observed that stimulation of the central end
{953} of a cut sensory nerve, or of the medulla oblongata, or of the
peripheral ends of both splanchnics and both vagi, causes a rapid
contraction of the spleen. Unsatisfactory as is our knowledge of
splenic physiology and of its exact relations to the maintenance of
life (for that the spleen is not the seat of a peculiar and exclusive
function has been demonstrated by the survival of individuals after
extirpation of the organ), at present certain theories of its nature
find pretty general acceptance. Thus, it is considered that in the
lymphoid tissue of the blood-vessels and Malpighian corpuscles
leucocytes are produced--that the cells of the splenic pulp appear to
take red blood-corpuscles into their interior, where their
disintegration takes place. There are not sufficient grounds for
believing that in the spleen red blood-corpuscles are formed. Recent
observations of Tizzoni, Crédé, and Zesas have led them to the
conclusion that they are made in the spleen; but Bizzozero and others
deny that this occurs except after serious hemorrhage.
[Footnote 1: _Journal of Physiology_, vol. iii., 3 and 4, p. 203.]
It is impossible to detect by palpation any part of a healthy spleen.
Its area may be approximately defined by percussion alone, though even
by this method it is not always easy to determine its position and
size. Loomis advises that the patient be placed upon his right side in
order to facilitate the examination. The anterior border of the spleen
is then "readily determined by the tympanitic resonance of the stomach
and intestines. Inferiorly, where the organ comes into contact with the
kidney, it is difficult, and often impossible, to determine its
boundary. Its superior border corresponds to the line which marks the
change from flatness to pulmonary resonance." The vagueness of these
directions is necessitated by the difficulties of the subject, the
splenic outlines being liable to frequent variations. Schuster and
Mosler give excellent reasons for prosecuting the investigation with
the patient in the right semi-supine position.
Acute Congestion of the Spleen.
Except within the physiological limits already referred to, acute
congestion of the spleen never occurs as a primary process. Under
pathological conditions it is known to take place under a great variety
of circumstances, principally, however, in connection with those states
of the system in which disease is supposed to depend upon some specific
principle or germ. To a minor extent it is probable that splenic
congestion accompanies nearly all febrile conditions, and from the
border-lands of health to that highest and most intense degree of
hyperæmia by which the organ acquires a volume and prominence that have
caused it to be designated as acute splenic tumor, all gradations may
be observed, though in many instances these may be so slight as to be
incapable of recognition clinically, and are only brought to our
knowledge through necroscopic examination. The congestion becomes most
marked in the course of the acute specific fevers. In typhus and
typhoid fevers, in small-pox, scarlatina, diphtheria, in epidemic
cerebro-spinal meningitis, in acute tuberculosis, in erysipelas,
puerperal fever, in conditions of blood-poisoning and in malarial
fevers, more especially those of more severe type, it reaches its
highest development. According to Friedreich, a form of pneumonia
(differing from ordinary croupous pneumonia in its serpiginous course),
acute coryza, and acute pharyngitis and tonsillitis are accompanied by
enlargement of the spleen in consequence of the septic nature of these
disorders. During the fever of secondary syphilis a splenic enlargement
purely hyperæmic in character may sometimes be detected. Similar
conditions are occasionally observed in a number of other affections.
This tendency of the spleen to active congestion is to be accounted for
by its peculiar anatomical structure, whereby unusual facilities for
hyperæmia are {954} afforded, more especially in the infective fevers,
in the course of which the organic germs which are supposed to
constitute their essential principles collect in the pulp, and by their
accumulation and multiplication serve to excite a more or less intense
determination of blood to the part, the organisms themselves being
taken up by the leucocytes and connective-tissue corpuscles composing
the pulp. We can thus account for the multitudes of these organisms to
be found in the splenic pulp after various infective disorders, as in
relapsing fever as observed by Ponfick, in pyæmia by Birch-Hirschfeld,
and in splenic fever of animals by various observers. The less intense
degrees of congestion occurring during the various specific fevers and
in many simple febrile disturbances are usually so slight as not to
attract attention. When the hyperæmia has been unduly prolonged, as
more especially occurs as a result of chronic malarial poisoning,
leucocythæmia, pseudo-leucocythæmia, or Hodgkin's disease, there is a
well-pronounced tendency toward permanent structural changes and the
development of hypertrophy.
SYMPTOMATOLOGY.--Milder degrees of congestion do not, generally, reveal
their existence by symptoms, and those of more pronounced character
give for the most part signs that are vague and nearly obscured by the
more prominent features of the pathological processes that occasion or
accompany the splenic changes. It may happen that acute splenic tumor
of considerable size may be quite painless. It has been objected,
indeed, that when pain accompanies splenic enlargements it is not
attributable to any sensibility of the spleen itself, but to the
participation of the investing peritoneum in the morbid action or to
the dragging of the enlarged organ upon the parts with which it is
connected (Mosler). Patients, however, will often complain of a dull,
aching pain and a sensation of weight in the left hypochondrium.
Occasionally, this pain may be severe and lancinating or may extend to
the shoulder. Headache and various digestive disorders--anorexia,
vomiting, flatulence, and diarrhoea--may prove distressing
accompaniments. Other symptoms, such as melæna, voracious appetite,
vertigo, extreme anæmia with its various concomitants, etc., belong
rather to conditions of protracted congestion where new formation and
true hypertrophy have been developed.
It is evident that it will often be extremely difficult, and sometimes
even impossible, to determine the extent to which symptoms are
occasioned by the splenic congestion or by the general affection to
which it owes its origin. Mosler declares that he is nearly always able
to detect during the cold stage of intermittent fever a peculiar murmur
over the splenic region and upward and downward in the abdominal
region, which he attributes to the contraction of the splenic artery.
This murmur he has not been able to perceive in chronic splenic
tumors.[2]
[Footnote 2: _Ziemssen's Cyclop._, vol. viii. p. 468.]
The normal splenic area can only be defined by percussion, and
congestion to a not insignificant extent may occur without revealing
itself by other symptoms than increase of the extent of percussion
dulness. When the organ projects beyond the margin of the ribs and can
be felt by the fingers of the examiner, it is enlarged, unless the
patient is the subject of displaced or of wandering spleen. But whether
the enlargement be due to hyperæmia simply or to hypertrophy can only
be determined by a consideration of all the concomitant circumstances.
Unless under the influence of chronic irritation or as a result of
mechanical hyperæmia, congestions of the spleen are commonly of sudden
development and of transitory duration. In ordinary inflammations, such
as pleurisy, etc., the degree of congestion is so slight as to be
unnoticeable; but as an epiphenomenon of the various specific fevers
the enlargement occurs rapidly and acquires a prominent interest in
many cases. Acute splenic tumor, for example, is almost of constant
occurrence during the course of typhoid fever, and, according to
Friedreich, its presence may {955} be ascertained some days before the
specific symptoms of the disease have declared themselves. A similar
early development has been claimed for it in diphtheria and other
affections. The congested spleen of typhoid fever and of relapsing
fever, however, differs from that of most other acute disorders in
returning to its normal dimensions much more slowly; and it is
important to remember that until the splenic tumor has disappeared
there is reason to believe the danger of relapse still imminent. In
most cases the enlargement disappears pari passu with the disorder that
occasioned it. In malarial fevers and in septic diseases the splenic
tumor may acquire excessive dimensions. Acute splenic tumor, however,
never attains the dimensions often encountered in chronic congestion
and hypertrophy.
PATHOLOGY AND PATHOLOGICAL ANATOMY.--Simple splenic congestion presents
at first no anatomical features differing from purely physiological
hyperæmia. There is simply more blood in the dilated vessels and
vascular spaces, and consequently in the viscus, than is usual. Very
soon, however, there is hyperplasia of the cells of the pulp.
Enlargement, tension of the capsule, and diminished consistency of the
spleen appear. The color will depend upon the condition of the capsule,
being most dark and blue when this is thinnest. In high grades of
congestion the parenchyma upon section will be found distended and
semi-diffluent, and after acute malarial fever (pernicious remittent
fever), the organ may resemble a bag of half-liquid pulp. Softening in
varying degree may be found after acute congestion from whatever cause.
In the congestions due to some infective processes at least additional
factors are introduced, although as yet definite knowledge of their
exact pathogenetic influence has not been attained. The observations
connecting minute organisms with the origin of these affections have
been so elaborate, so carefully and conscientiously reported, extend
over such wide and varied fields, that it is difficult to refuse to
place reliance in them. It seems that in a number of affections the
presence of these microscopic organisms is constant and essential, and
that the splenic congestion that accompanies them is a direct result of
their presence in the spleen itself. The micro-organisms will be found
infesting the cells of the pulp, and, so far as we have definite
knowledge, they show peculiar characteristics according to the
particular infectious disease to which the patient succumbed. While the
conditions in acute splenic tumor are identical with those of
inflammation, and in the affections properly designated as septic,
should the life of the patient have been sufficiently prolonged, may be
found to have led to the formation of embolic centres with hemorrhagic
infarctions and abscess, in infectious diseases not septic they do not
prove equal to the production of suppuration. Where the action is
acute, resolution will speedily follow the subsidence of the febrile
process. But in prolonged hyperæmia new formation will be developed,
and the enormous collection of leucocytes will give a reddish-gray
color to the organ. This change will also be sometimes observed in the
spleens of those in whom the infectious diseases have run a more
protracted course.
DIAGNOSIS.--Acute splenic tumor, if at all pronounced, may usually be
diagnosticated without much difficulty. The development of an
enlargement in the splenic region, with pain and tenderness to
pressure, during the course of any acute febrile disease will nearly
always indicate splenic hyperæmia. It may sometimes be difficult to
determine whether the tumor may not have existed prior to the invasion
of the present malady. In such cases one must have recourse to the
previous history of the patient, or, failing in this, must observe the
behavior of the tumor upon the subsidence of the general affection.
PROGNOSIS.--The prognosis of acute congestion and acute splenic tumor
will depend rather upon the exciting cause. When of simple origin it is
of but insignificant importance. Even in specific fevers the spleen
will in most {956} instances return to its normal volume upon the
establishment of convalescence. Rupture of the spleen has been known to
occur in congestion from severe malarial fever, but this is a most rare
accident in the absence of traumatic influences. The congestion may
become chronic, and frequently does become so, in cases where the
stimulus continues to exert an influence upon the spleen, as is done in
chronic malarial poisoning.
TREATMENT.--The transitory hyperæmia of a brief malarial attack or of
any ordinary febrile seizure will disappear with its exciting cause,
and will require no special treatment. For the acute congestions of
most specific fevers but little is to be done except through attention
to the general condition: it is only when pain and discomfort in the
splenic region are sufficient to attract the attention of the patient
that measures for the relief of the congestion will be necessary. In
that most common exciting cause of it, malarial fever, patients will
often complain bitterly of the pain in the left hypochondrium for some
time after the febrile attack has been overcome. In such cases it may
be pretty safely concluded that the poisonous influence of the malaria
has not been entirely overcome, and the proper employment of quinine
and other derivatives of Peruvian bark, and bitter tonics, will
undoubtedly prove most serviceable. In very many cases benefit may be
derived from local applications. Experiment has clearly shown that the
stimulation of the splenic nerves is capable of effecting a notable
reduction in the bulk of the organ. Clinical experience gives similar
proofs, and cold effusions, evaporating lotions, etc. will sometimes
secure prompt unloading of the spleen; indeed, Mosler considers that
there is danger in treating the acute splenic tumor of typhus fever of
inducing unfavorable changes by the too sudden reduction of its bulk by
local applications. The use of stimulating applications to the splenic
region will also prove beneficial in many cases. Among the most
valuable of these will be found the tincture of iodine.
Chronic Congestion and Enlargement of the Spleen.
Within narrow limits there may be simple increase in the size of the
spleen from hyperæmia, without alteration of the relations between its
structural parts. The common results, however, of hyperæmia of long
standing are overgrowth of the elements of the reticulum, with new
formation of connective tissue and hyperplasia of the pulp-tissue. This
condition of chronic enlargement or hypertrophy of the spleen may
develop as a result of chronic active hyperæmia or through passive or
mechanical engorgement of the portal system. Chronic active hyperæmia
of the spleen is in much the greater number of instances caused by
chronic malarial poisoning. It also occurs as a cause or a result of
leucocythæmia and of pseudo-leucocythæmia or Hodgkin's disease, and is
always associated with more or less true hypertrophy of the structural
elements of the organ. Enlargement from the above-mentioned causes
constitutes the vast majority of those abnormalities generally
designated as chronic splenic tumor. In persons living in malarious
countries, and subjected for prolonged periods to the intoxicating
influence, the peculiar splenic enlargement tends to become chronic.
After the earlier attacks the spleen returns more or less promptly to
its normal dimensions. Usually it is only after repeated attacks of
intermittent or remittent fevers, and often only after exposure to the
malarious influence for years, that the splenic tumor becomes
established as a permanent disorder and assumes the characteristics
that have secured for it the popular denomination ague-cake. Persons
living in the localities referred to may develop this enlargement
without ever having had unequivocal attacks of malarial fever. They
will betray, however, the effects of the poisoning by malarial
neuralgias and {957} neuroses or by a well-marked periodicity in the
course of simple maladies, or they will exhibit its effects by the
peculiar facies and by general paludal cachexia. Under these conditions
the splenic enlargement sometimes attains enormous proportions.