Symptoms.—About 50 per cent. of hy datid cysts are found in the liver. When these are of considerable size, the tumor or tumors are detectable by palpation and otherwise, the size of the organ be ing sometimes markedly increased. When these are small, they may not be- distin guished or give rise to any disturbances. When they occur in the epigastric region on the anterior surface of the organ, they can be distinctly appreciated by touch, a feeling of density and occasionally a fluctuation being sometimes elicited. Occasionally they are found near the left suspensory ligament, disturbing the posi tion of the heart upward, and an area of percussion-dullness can be demonstrated in the lower sternal and the left hypo chondriac regions. If the tumor occur in the posterior surface of the right lobe, the liver is enlarged upward, encroach ing upon the pleura, and the area of dull ness in the axillary line is higher. A percussion-fremitus can be detected if the cyst lies very subcutaneously. This consists of a tremulous or vibratory move ment conveyed to the fingers of the left hand while percussing at the same time with the right.
Subjective symptoms of pressure or dragging and occasionally pain are ex perienced in the region of the liver; lit tic more disturbance is caused than this. Where suppuration occurs, there are the usual symptoms of pyaemia, along with jaundice and rapid emaciation. Perfora tion may take place externally or into the stomach, colon, pleura, or the bron chi; where this is into the pericardium or inferior vena cava, it is, of course, fatal. To differentiate between hydatid cysts and other tumor-masses it is best to make an exploratory puncture. In some instances hooklets may be found in the fluid, which, as a rule, is clear, of a neutral reaction, and varies from 1005 to 1009 in specific gravity.
The presence of a marked enlargement in the left lobe of the liver, irregular in shape and painless, or in the epigastric region, a smooth fluctuating mass, giving o b the sensation of an elastic growth, sug gests hydatid disease; this is especially the case if, besides, there is hydatid tremor. A syphilitic tumor of the liver
is firm and rarely fluctuates. Between hydatid disease and cancer of the liver it is difficult to distinguish except through the clinical history. Hydronephrosis may readily be mistaken for hydatid dis ease, and can only be distinguished by exploratory puncture. The lung is af fected in about one-fifth of the cases, the symptoms being those of pneumonic compression along with displacement of the heart. The pleura is sometimes pri marily affected, the signs being those of an ordinary effusion; but the line of dull ness is generally quite irregular and there is rarely set up an acute pleurisy. Echin °cocci of the lung may, when small, cause very little disturbance, but when large the symptoms of compression ob trude themselves; inflammatory changes may be set up, resulting in hmmorrhage. But this is rare.
Treatment. — Medicines administered internally can have little or no effect ' upon the course of the disorder. When the cyst is large or annoying it must be treated surgically. Aspiration of the contents is harmless, and should be at tempted before more radical measures. Recovery, in most instances, follows in , cision and evacuation of the cysts.
Ab scess of the liver caused by the echino coccus is obviously a serious disorder. In a large number of cases which come to autopsy the cyst is found to be harmless and the parasite dead.
The kidney is sometimes infested by the echinocoeci, and symptoms are set up resembling an hydronephrosis. The nervous system is occasionally affected, especially the brain—most frequently the cerebrum. The symptoms are vague, being those of tumor.