Sometimes the tumour, instead of becoming visible in the belly, may press upwards the right side of the diaphragm and the base of the lung, and project far into the right side of the chest. In such a case the lower ribs on that side are pushed outwards, and the physical signs very much resemble those of a pleuritic effusion. Even if the tumour project but slightly upwards, the respiratory sounds are usually very weak at the right posterior base of the chest, and the percussion-note may be a little higher pitched, with increased sense of resistance.
If, instead of projecting from the convexity of the organ, the hydatid sac protrudes from the under aspect of the liver, pressure signs may be observed in connection with the biliary and vascular conduits. It is in these cases that jaundice, ascites, and oedema of the feet may be noticed.
If spontaneous suppuration take place in the hydatid sac, the symptoms vary in severity. They may be grave or trifling. In some cases a slight rise in the temperature of the child occurs ; he looks a little poorly ; coughs, and complains of pain when his belly is manipulated, but nothing is noticed to excite the alarm of the parents. In other cases he shivers, and his temperature undergoes the rapid alternations peculiar to suppura tion ; the swelling increases in size, and, if left alone, either points at some part of the surface, or sets up adhesive inflammation with a neighbouring organ and bursts into it. The proof that such an abscess is the result of a hydatid cyst is the finding of hydatid membranes or booklets in the evac uated pus.
If the cyst be not interfered with, it will probably in time destroy the life of the patient by bursting into some neighbouring organ. Bohn has related the case of a child eight years of age, in whom the sac burst into the bowel. The patient recovered ; but a favourable issue to so severe a complication must be rare. The cyst usually bursts into the cavity of the chest—into the pleura or the lung. Death is a frequent consequence of either acci dent. In the latter case pneumonia is set up, and the patient dies worn out by the profuse discharge.
Hydatid of the liver may be complicated by a similar development in the spleen, in the folds of the mesentery, or beneath the peritoneum. It is important to be aware of this possible distribution of the echinococci, as the presence of various tumours in the abdominal cavity may tend to em barrass the diagnosis. Sometimes the lungs as well as the liver are af fected. These various cysts often appear to be of different ages, and in that case may arise from absorption of embryos at different periods of time. It has been suggested that germs generated by the elder hydatids may be carried along by the current of blood and deposited in other organs ; but in this case they could hardly be conveyed from the liver to the spleen or mesentery against the direction of the blood-current.
Diagnosis.—The diagnostic features of a hydatid tumour of the sliver are :—A. localised swelling of the organ, smooth, elastic, and painless, ac companied by no signs of jaundice, ascites, prominence of the superficial abdominal veins or swelling of the feet, and giving rise to no pyrexia or impairment of the general health of the child. If the characteristic frem itus can be detected on percussion of the swelling, the evidence is com plete.
If suppuration have occurred in the sac there may be some fever, and the child looks ill and pale. Pain may be complained of in the right hypo chondrium, and the tumour may be tender when pressed upon.
If the tumour feel solid to the touch, as was the case in a child who was under my care in the hospital, the diagnosis would rest upon the slow growth and painless condition of the swelling, and the general absence of symptoms. I have never met with a sarcoma or soft cancer of the liver in a child, but it is possible that this disease might be mistaken for a hydatid cyst. The growth, however, would be more rapid in such a case, and we should expect to find some impairment of the general health. In any case of doubt an exploratory puncture with a fine trocar and can ula will remove all hesitation. If a non-albuminous, clear, or slightly turbid fluid escape, especially if booklets can be discovered in it by the microscope, the diagnosis of hydatids is clear.
If a large cyst project upwards into the chest and compress the base of the lung, it is often mistaken for a pleuritic effusion. The error is one which is easily fallen into, for in both cases there is complete dulness, with increased sense of resistance and weak breathing, all round the right side of the chest. A distinction may be made by observing that in the case of a hepatic cyst the upper line of dulness is curved with the convexity up wards, and that the dulness, therefore, reaches higher in the mid-axillary line than at either the front or the back of the chest. In pleurisy an exactly opposite condition is found. The upper margin of dulness is con cave, being less elevated in the infra-axillary region than at the back. If there is any suspicion that the disease is not pleurisy, an exploring trocar, allowing of examination of the fluid, will soon set the matter at rest. The fluid drawn from the chest in pleurisy coagulates on boiling, while the hyclatid fluid, as has been said, is non-albuminous.