mean average, maximum, at 27 months; minimum, at 3.5 months; but this
is based on a confessedly small contingent of cases. The first
symptoms, dry cough, pain in the chest, difficulty of breathing, may
last for some years without alarming the patient. After the more
dangerous phenomena appear the course is often more rapid. The history
of cancer in the lung in the main corresponds with cases of similar
types of cancer elsewhere. The grave symptoms appear earlier in cases
of mediastinal cancer than in cancer of the lungs proper. Death may
result from asphyxia; from bronchial obstruction; from pulmonary oedema
occurring suddenly, as in chronic alcoholism; from embolism of the
pulmonary artery; or from pleural effusion. Life may gradually ebb away
through general asthenia with malnutrition; in some {464} remarkable
cases the same result is accompanied by hectic fever and the typhoid
phenomena, with evidences of tissue-disintegration.
COMPLICATIONS.--The complications of pulmonary cancer have been already
outlined. They are chiefly the bronchial, pleural, and mediastinal
processes. Primary cancer of the lungs possesses a feeble tendency to
metastasis.
DIAGNOSIS.--The most valuable assistance is derived from a close study
of the personal and hereditary history. Whenever a new growth has been
extirpated, the possibility of its reappearance in the lungs should
always be remembered. The most disciplined comparative analysis of
physical signs may be fruitless. The origin of a primary growth from
the roots of the lungs may help to interpret the physical signs, and
examination of the sputa should never be omitted. In secondary cancer
the history of the case may include the removal or development of
morbid growths from other parts of the body. Any pulmonary symptoms in
these cases become more suspicious than they would in persons in whom
no signs of cancerous diathesis have ever made their appearance. This
rule must not be pressed too far, for forms of pleurisy, bronchitis,
and pneumonia or phthisis may be the explanation of the symptoms.
In the differential diagnosis it is a matter of universal experience
that some form of chronic pleurisy is the most frequent source of doubt
to the clinician. It has been said by Wintrich that vocal fremitus in
cancer is more often present than absent. If there is much pleural
effusion, paracentesis will be helpful in two ways. When the fluid is
turbid, highly albuminous, with a large proportion of coagulable
fibrin, it is an evidence of its inflammatory origin; but if it is
clear and limpid, and upon standing gives but a delicate veil of
pseudo-fibrin, it indicates a passive or mechanical cause. If the fluid
evacuated should contain any considerable amount of blood, such a
peculiarity in association with the other symptoms already indicated is
to be regarded as probable evidence of the existence of cancer of the
pleura. If the external veins of the thorax are enlarged, they indicate
a deep-seated cause of pressure. In malignant disease with retraction
there may be less deepening and narrowing of the intercostal spaces on
full respiratory movement than is associated with chronic pleurisy:
there is usually greater volume and nearness of the respiratory murmur,
although this is more noticeable on the left than on the right side,
since the liver is present in the latter. The greater severity of the
local symptoms and the increase in gravity of the disease must be
contrasted with the features of a disease in the decline, as is the
case in chronic pleurisy. Walsh considers that "the normal position of
shoulder, spine, and scapulæ distinguishes cancer from the results of
simple pleurisy." In addition, we have the shorter duration of cancer,
which is never over two and a half years, often less. The lemon-hued
cachexia is so frequently absent that the inference from general
inspection of the features is marred. From fibroid forms of pulmonary
disease we have the pressure-signs, giving evidences of mediastinal new
formation; also the possible prune-juice expectoration of cancer. The
retraction and displacements of the intra-thoracic organs, chiefly the
heart, are greater in fibroid disease than in either pleurisy or
cancer.
In addition, the history of phthisis includes a higher thermometrical
record, frequent hæmoptysis, and abundant sputa. Physical diagnosis in
cases of phthisis reveals a destructive process involving extensive
areas of pulmonary tissue in a comparatively regular sequence. The
cancerous process is more local or involves the tissues in an irregular
order. Moreover, the asphyxial hue and the pressure-symptoms
preponderate in malignant disease. To distinguish the cancerous process
from simple forms of bronchitis we may observe the frequency with which
the symptoms of bronchitis recur in cancer {465} without exposure to an
adequate cause; by the absence of marked tendency to hypertrophic
emphysema; by the resistance to treatment; by the persistence of
dyspnoea as a prominent symptom; and by the gradual development of
patches of hypostatic congestion. To differentiate from aneurism we
should consider the occupation of the patient, the absence of syphilis
or other causes of arterial disease, the history, the location of the
tumor, and the absence of the murmur. Hydatid cysts may simulate
cancer, but this disease is rare in America. (Vide PULMONARY HYDATIDS.)
In cancer of the liver, as that organ enlarges pulmonary symptoms may
occur from irritation, and congestion or oedema be produced. We must be
content to mention the possibility of error, and decide in each case
after a crucial analysis of the abdominal or thoracic symptoms.
PROGNOSIS; TREATMENT.--The prognosis is fatal; the treatment purely
palliative. It is quite justifiable to relieve pain by the hypodermic
use of morphia, cough by chloral or the usual narcotics, and fetor of
the breath may be palliated by inhalation of carbolic acid or other
disinfectants. Dyspnoea may be alleviated by the use of strychnia as a
respiratory stimulant--by inhalation of nitrate of amyl or small
allowances of chloroform or digitalis. Paracentesis thoracis must often
be resorted to in cases of pleural effusion, even although the relief
it affords be temporary.
{466}
PULMONARY HYDATIDS.
BY EDWARD T. BRUEN, M.D.
DEFINITION.--A disease in the lungs consequent upon the entrance into
the human system of the eggs of a small tape-worm, whose usual habitat
is the upper half of the small intestine of the dog.
SYNONYMS.--Tænia echinococcus; Acephalocyst. _Fr._ Kystes hydatiques du
poumon; _Ger._ Lungenechinococcus.
HISTORY.--Unmistakable references to this disease are found in the
writings of Hippocrates, Aretæus, Galen, and other early writers. For a
long time, however, the animal character of the hydatid cyst was not
recognized, but confounded with slowly-developed local dropsies of
various orders and with lymphatic dilatations. Their animal nature was
suspected by Hartman in 1685, but their origin was not separated from
the cysticercus. In 1766, Pallas clearly distinguished the two species,
and this author was followed in a more positive way by Groeze in 1782.
Laennec in 1804 carefully studied the hydatid cyst as found in the
sheep, recognizing even the mode of reproduction, but he erroneously
described the same parasite, when existing in man, as a distinct
animal, which he termed acephalocyst. Since 1821, Bremsen, Davaine,
Küchenmeister, and others have definitely settled the true mode of the
entrance of the Tænia echinococcus into the human system, and the
subsequent development of the hydatid cysts. The development of the
parasite resembles that of the cysticercus. Like the latter, the larvæ
infest the bowels of certain animals, and take their further
development in a different animal or species, forming vesicles which
are distributed in the parenchyma of the different organs, and in this
way more or less seriously compromising the functional life of the part
in which they occur.
ETIOLOGY. (See article on INTESTINAL WORMS, by Leidy.)--Hydatids have
been found in the human subject in all countries, but especially in
France, Germany, and in the north of Europe. They are rarely found in
North America, and the fact that the majority of cases seen here have
occurred in foreigners favors the probability of the hydatid disease
having been imported. But there are two countries where it may be said
to be endemic--Iceland and Australia. Finsen found 1 out of every 43
inhabitants affected with this disease in the district of Ofjord in
Iceland. Hydatids are communicated to the human race through the system
of the dog, and in Iceland the proportion of these animals to the
population is probably more than 1 to 3, a recent census recording
20,000 dogs to 70,000 inhabitants. Hydatids usually enter the system
through the digestive and respiratory organs. The Icelanders are
excessively uncleanly and careless of the laws of ventilation. In the
winter season both men and women are confined to the house in company
with their dogs, and in consequence the air is impregnated, and
oftentimes the drinking-water contaminated, through their dejecta,
which contain thousands of the eggs of the echinococci. The largest
{467} number of cases occur in the agricultural districts, since the
dogs are more required there than on the sea-coast.
In Australia large numbers of dogs are maintained to guard the sheep.
The droppings of these animals, dried by the hot winds, are inhaled as
dust. It is curious to note that in Australia, where the high winds
prevail, the proportion of pulmonary hydatids is very large, while in
Iceland, where the drinking-water is the principal medium of
communication, the lungs are less often affected than other viscera.
Finsen's records in the latter country show 255 cases; of these, 176
occurred in the liver, and only 7 in the lungs. In both Iceland and
Australia women are more subject to echinococci than men. This is
possibly accounted for by the facts that the women take care of the
dogs and wash the vessels from which they eat, and are also less
protected by hair about the mouth and nose than men.
The disease occurs most often between the ages of twenty and thirty
years, but it has been found in children of four years of age. Before
ten and after sixty the proportion of cases in both sexes is equal. The
malady is not hereditary, but uniformity of environment accounts for
the propagation in communities. Pulmonary hydatids occur as primary
formations in the lungs, but may be secondary to similar growths
elsewhere, especially in the liver. There is, however, scarcely a
tissue in the body in which hydatids have not been found.
MORBID ANATOMY.--Hydatid cysts consist of sacs of various sizes, from
that of a pea to an orange or even an adult head. They are usually
globular in shape, and attached by a vascular membrane to the organ in
which they are situated. The walls of the cysts are composed of a few
laminæ of indeterminate membrane of varying thicknesses, commonly
depending on the age of the cyst. In young cysts they occur in direct
contact with the lung, but as they grow larger a thicker investment is
formed, and large old cysts which have generally undergone spontaneous
rupture often have a dense leathery sac. Walsh asserts that the parent
cyst lies in direct contact with the lung-tissue, and, unlike that of
the liver, is rarely surrounded with a thick shell or cyst-wall of
pseudo-areolar tissue. The interior of the pouch is smooth and of the
aspect of serous membrane without epithelial covering. The parent cyst
contains daughter cysts which are single or multiple, and a liquid the
proportion of which is variable. This liquid is nearly limpid, and
non-coagulable by heat or acids; it deposits by evaporation crystals of
chloride of sodium.
Commonly, only one hydatid tumor is found in the human lungs, although
in animals multiplicity of cysts is the rule. They are usually located
in the base of the lungs, and are thought to be more common on the
right side, but they may occupy any portion of one or both lungs. They
have been found in the pleura, the bronchi, the pericardium, and the
thyroid gland. In the pleural cavity they may be attached to both the
costal and the visceral pleura; in the latter case they may form an
outgrowth from the lung into the pleural cavity. Authorities differ as
to the condition of the neighboring lung-tissue, some stating that the
cysts are rarely surrounded by healthy lung-substance, while others
assert the contrary. Since the growth of the cysts is often very slow,
the accommodating power of the lung is remarkable when no
constitutional mischief exists. In some instances the rapid enlargement
of a cyst has been accompanied by certain forms of pneumonia, secondary
inflammatory lesions, congestion of the neighboring tissue,
splenification, or even gangrene.
Hydatids situated either in the lung or pleura may rupture into the
bronchial tubes, and thence be discharged by cough and expectoration,
or they may open externally like a pleural empyema, or even rupture
through the diaphragm into the intestines or peritoneum. None of the
above accidents are necessarily fatal, not even the latter, unless the
fluid be puriform. {468} Empyema with pneumothorax usually follows
rupture into the pleura. Finsen observes that a general urticaria may
follow the rupture of a cyst into a serous cavity. In old cases, after
rupture of cysts, pulmonary changes may almost always be found. The
ruptured cyst may become a suppurating cavity, suggesting the possible
development of phthisis. In some cases hydatid formations have been
described with coexisting catarrhal or tubercular disease, or these
processes may occur as a complication without rupture of the cyst.
SYMPTOMS.--The symptoms of hydatid cysts are obscure, and the physical
signs difficult to analyze when the cysts are small. They are more
suggestive when the cyst becomes large enough to contain a pint or more
of fluid. The outline of the cyst is usually globular, and is imbedded
in healthy or nearly healthy lung-tissue. According to Bird, the
physical signs correspond with those familiar to us in pleural
effusions: absolute dulness or flatness on percussion, with absence of
respiratory murmur over a space of the chest-wall not smaller than the
palm of the hand; vocal fremitus and resonance are also abolished. The
expansion of the chest is more or less deficient upon the affected
side, but seldom with any change on mensuration.
The area of the above physical signs usually presents a rounded
outline, limited by a line of demarcation so exact that it can be
mapped out with pen and ink, but is unaltered by position. Their
location is generally in the lateral or infra-clavicular regions;
beyond the boundary-line percussion is vesiculo-tympanitic resonant or
normal, and the respiratory sounds begin at the very margin of the
pen-and-ink line, and, though probably harsh and puerile in character,
are indicative of healthy lung-tissue.
Pulmonary hydatids can seldom be examined by palpation, but all authors
allude to a frémissement or peripheral fluctuation which may sometimes,
but not invariably, be detected by palpation over the intercostal
spaces. Davaine directs palpation as one would palpate an abdominal
cyst. The sensation of fluctuation is as though the fluid were
gelatinous; when the quantity of liquid is excessive this movement is
not perceptible. It is most recognizable when there is but a single
hydatid in the parent cyst (Jobert). The frémissement cannot be felt
when the sac has undergone atheromatous degeneration, because there is
then no liquid, and the cysts are withered, agglutinated to one
another, and the tumor is inelastic and hard. By auscultating the tumor
while practising percussion one may hear more or less positive
vibrations resembling those produced by a bass string (Briançon).
The general symptoms of pulmonary hydatids are of mechanical origin:
pain, dyspnoea, cough, with duskiness of the surface, all of which are
more or less marked according to the size and location of the tumor and
its rapidity of growth. A phthisical appearance is possible, with
deterioration of the blood-crasis and progressive loss of flesh. Marked
clubbing of the finger-ends and incurvation of the nails have been
noticed, all of which symptoms have disappeared after the hydatid cyst
has been tapped or expectorated. Cough nearly always accompanies this
disease, as it does a large pleural effusion. The expectoration is a
glairy mucus, sometimes stained with blood; when local bronchitis
occurs as a complication, it may become muco-purulent. There is much
diversity of opinion as to the frequency of hæmoptysis, many authors
looking on it as a rare symptom. According to Bird, there is seldom or
never profuse hæmoptysis, though several ounces have been expectorated
at a time in an aggravated case where tapping had been long delayed.
The cause of hæmoptysis is usually pressure of the growing cyst upon
the pulmonary veins, leading to extravasations of blood.
If dyspnoea with deficient aëration of the blood, wasting, clubbed
fingers, and expectoration persist after the expulsion or death of the
hydatid, the probability is in favor of some associated pulmonary
inflammation. When {469} a hydatid cyst ruptures into the bronchial
passages, there is serious likelihood that the patient may choke or
suffocative dyspnoea supervene. The quantity of entozoal substance
voided at any one time varies from a few microscopical fragments up to
a pint or more of unbroken acephalocysts. The expectoration of
acephalocysts may continue several months. Serious general pulmonary
symptoms precede and follow this accident. When rupture has taken place
into a bronchial tube, there are the usual physical signs of a
pulmonary abscess or large vomica. The sac usually suppurates, and
there is a constant expectoration of blood, pus, and half-putrid
acephalocysts of excessive fetor, and often portions of gangrenous
lung-tissue. With these symptoms the temperature is sometimes of a low,
remittent type, with hectic and sweats. The symptoms resemble those of
empyema or advanced phthisis, and may continue for months, until the
patient, in most cases, sinks from exhaustion, unless relieved by the
evacuation of the sac and its contents. When hydatids develop in the
pleural cavity the signs are identical with a localized pleural
effusion.
Nothing has been said to differentiate pulmonary-hydatid expectoration
from cases where an hepatic hydatid cyst has burst into the lungs, and
the diagnosis may be very difficult. The physical signs of enlarged
liver are present, also the antecedent symptoms of disordered hepatic
action, especially intestinal indigestion and the staining of the sputa
with bile. If the cyst has undergone suppuration, the symptoms may be
allied to those of hepatic abscess.
The nucleation of testimony favors the view that a latent or slow
growth is by far the most common history of hydatids. Their duration is
very variable: patients may harbor them for a long time unconsciously,
even over a period of sixty years. This is corroborated by Finsen, who
reports cases in which the disease lasted sixteen, eighteen, and
fifty-two years, proving this by stating that these individuals had
left the country where the disease was endemic, and were residing
during these periods where the malady was rare.
TERMINATIONS.--30 or 40 per cent. of cases terminate in recovery if the
cysts spontaneously burst, death being caused in others by suppuration
and exhaustion. There is, in addition, the risk of sudden death from
the rupture of a large cyst in the lung, and consequent filling up of
the air-passages by its contents. The cysts may sometimes undergo
atheromatous changes in which the hydatids resemble crushed
grape-seeds. Microscopically, one finds a puriform fluid, plates of
cholesterin, crystals of hæmatoidin, hooklets of echinococci, and
débris of membranes. Again, the cysts may resemble a caseous or
cretaceous tubercle without special characteristics. This may be looked
on as a species of spontaneous cure. The growth of hydatid cysts may
bring about by pressure such a state of chronic pulmonary engorgement
that it affords a predisposing condition favoring the development of
tubercular phthisis.
DIAGNOSIS.--The differential diagnosis is necessarily difficult. The
nationality of the subject and the presence of a predisposing
environment should always be remembered. If the disease progresses
rapidly without interference, the diagnosis may be complicated by the
development of patches of bronchitis or pneumonia with rusty sputa. The
bronchitis is, however, local, which, taken with the physical signs of
a cyst, may be suggestive. The only absolute evidence of the existence
of hydatids in the lungs, whether primary or secondary, is the
appearance in the sputa of the characteristic cysts or portions of
them, such as fragments of the hooklets of the echinococci. This,
unfortunately, occurs as a late accident in their history. If the
boundaries of the cyst can be recognized, it is justifiable to resort
to paracentesis, and thereby withdraw some fluid for examination. The
physical signs of local serous effusion, globular in shape, not evenly
{470} distributed around the circumference of the chest, is one of the
best differential evidences between hydatids and pleural effusion.
Moreover, there is no fever in hydatids unless after rupture, or with
extensive phthisical complication, while there is a history of fever in
some stage of most cases of pleurisy. Hydrothorax is differentiated
through its being bilateral and by its etiology. From local encysted
pleurisy the only resort is exploratory puncture and the question of
the probabilities in each case. In the same way paracentesis removes
doubt whether there be mediastinal tumor, solid tumor of the lung, or
circumscribed pneumonic abscess; in the latter the general history of
each case is helpful. From phthisis we must have recourse to the
physical diagnosis already mentioned as belonging to hydatids. An
unbroken cyst in the liver, high up and far back on its convex surface,
may not be distinguishable from one in the base of the lung immediately
over the liver or one in the cavity of the pleura.
PROGNOSIS.--According to Reynaud, this depends on--1, whether the
hydatid is single or multiple; 2, whether the pressure is exercised on
blood-vessels or bronchi; 3, if hydatids are discovered elsewhere; 4,
size of cyst; 5, alterations in the walls of cysts; 6, whether
complicated with any other disease or independent.
If there is a tendency to pulmonary phthisis, inherited or acquired, or
if this disease exists as a complication, it forms an unfavorable
element in the prognosis. Persons once affected with hydatids are more
susceptible to a second invasion of the parasite. The practicability of
treatment by tapping is also an element in the prognosis.
TREATMENT.--Naturally, the preventive treatment rationally deduced from
the now distinctly-understood causes should be practised. The
water-supply should be protected from sources of contamination, and in
addition the inhabitants of countries where the disease is prevalent
should, as far as practicable, use boiled or stone-filtered water and
refrain from eating water-cresses or plants of like character wherever
these are liable to be contaminated.
Many drugs have been administered, among them the bromide and iodide of
potassium; solutions of salt are also said to be deleterious to the
life of the echinococcus; Laennec even prescribed salt baths. Tincture
of kamela has been recommended by Hjaltelin, a physician in the employ
of the Danish government in Iceland. He administered it in doses of
thirty drops daily to adults, continuing its use during a month or
more. It has a distinctly irritating and destructive effect on the
acephalocyst (Bird). Turpentine, from its well-known anthelmintic
powers and ready diffusibility, has naturally suggested itself as a
remedy, and according to some has proved of great service in many
instances, while in others it has signally failed.