A system of practical medicine. By American authors. Vol. 5

by Unknown

Pacchionian bodies are very common in the brain, and are really small fibromata. They may form true tumors (Cornil and Ranvier) capable of wearing away the bones of the cranium. In fact, even when small they may have corresponding indentations in the skull. They are not to be mistaken for tubercle. Clouston³⁵ has described excrescences from the white matter of the brain, growing through the convolutions, projecting through the dura mater, and indenting the inner table of the skull; which new growths he calls hernia of the brain through the dura. We have not seen such a condition described elsewhere, and think that we have here probably Pacchionian bodies growing from the pia mater. They were found in a case of tumor of the cerebellum.

³⁵ Journ. Ment. Sci., xviii. p. 153.

A cystic formation, constituting a veritable tumor, not unfrequently occurs in the pituitary body and mounts into the third and lateral ventricles. Echinococci and hydatids also occur, and have the same natural history as these parasitic offspring have when found in other parts of the human body.

Obernier refers to an enchondrosis of the basilar process. Our table presents one case of enchondroma.

Some of the gross appearances found on autopsies of tumors of the brain are worthy of note. Often an area of congestion or inflammation, especially of the membranes, is seen about the new growth, and the brain-substance in its immediate vicinity is much more frequently softened. The cerebro-spinal fluid is increased, and, especially when direct pressure has been exerted upon the veins of Galen, are found distended lateral ventricles. When a tumor does not approach the surface, but has attained some size, the hemisphere in which it is located often has a bulging appearance, crowding over upon its neighbor, and the convolutions are flattened by the pressure. The cranial nerve-trunks are occasionally involved in or stretched by the tumor, and also occasionally the bones of the vault or base of the cranium are extensively eroded. This happens especially in cancer and osteo-sarcoma.

A few remarks should be made about the methods of making post-mortem examinations and the gross appearances and conditions likely to be found in brain-tumor cases. As not a few intracranial tumors are connected with the bone or with the dura mater, the latter being adherent to the skull-cap in some positions because of inflammation arising from the seat of the growth, especial care should be taken in removing the calvarium. Examination of the external surface of the dura mater will sometimes reveal the presence of a growth beneath or incorporated with this membrane. The dura mater should not be roughly dragged from the surface of the brain, but should be carefully removed by a process of partial dissection. During this process a meningeal growth will sometimes be found growing apparently from the fused membrane. In such cases it is usually better to so proceed as not to entirely separate the outer membrane from the growth. Indeed, this cannot be done sometimes without injury directly to the specimen, and especially to its cerebral surroundings. The dura mater having been removed, a marked opacity, sometimes a dirty-brown hue shading off into a lighter color, will indicate to the eye the probable presence of a tumor beneath and growing from the pia mater of the cortex. In such a case, and even when no such appearance is present, but a tumor is suspected, the fingers passed carefully over the cerebral surface will feel a hard, and it may be nodulated, mass at some position. A growth, having been located in this way, should not be roughly handled or at once examined by section. An effort should be made to accurately localize it, not only with reference to lobes, but also with reference to convolutions and fissures, and even special portions of these. This is best done, after a thorough examination has been made of the pia mater, by carefully stripping the pia mater from the brain, beginning at points some distance from the growth and gradually approaching it, and leaving the pia mater for a short distance around the growth connected with it. The location having been fixed and other portions of the brain having been examined, if it is not possible or desirable to retain the entire brain as a specimen, a block should be removed embracing a considerable portion of healthy brain-tissue on all sides of the tumor. In order to study the gross internal appearance of the tumor, it is a good plan to make a clean section through the middle of the tumor. From each side of this cut fragments can be taken for microscopical examination without deranging appreciably the size and appearance of the tumor.

When the tumor is not meningeal or cortical, or not situated at the base or floor of the skull, its presence may be revealed, when it is in centrum ovale and of considerable size, by either hardness or fluctuation of the hemisphere in which it is located, this fluctuation not being due to the tumor itself so much as to the breakdown of tissue around it. Large sections in known positions with reference to convolutions and ganglia should be made when examined for tumors deeply situated. If possible, sections close to and just before and behind the growth should be made, so as to assist in the accurate localization.

Small tumors are not infrequently overlooked by careless observers, and even growths of considerable size have escaped discovery by one examiner to be found by another. Tumors in certain special localities, as between the temporo-occipital lobe and the superior surface of the cerebellum in the great longitudinal fissure, or small growths in the substance of the cerebellum or deep in the Sylvian fissure, are more likely than others to be passed by, although this, of course, is not likely to occur when the examination is made by a competent or careful physician.

DIAGNOSIS.—The diagnosis of the existence of an intracranial tumor, as a rule, is not difficult. It can be made with greater certainty than that of almost any other serious encephalic disease.

It is sometimes important to decide as to the nature of an intracranial neoplasm, particularly whether or not it is syphilitic. Little is to be gained by following the plan adopted by some physicians, of treating all cases as if they were due to syphilis, on the principle that these are the only forms of tumor which can be reached by treatment. The pitiable condition of such patients is sometimes thus made worse. In every case careful and persistent efforts should be made to obtain an authentic previous history from the patient. Whenever possible the physician should search directly for the physical evidences of the former existence of syphilis—for cicatrices on the genitals and elsewhere, for nodes and depressions, for post-cervical and other swellings, etc. A history of previous disease of the throat and of pains in bones and nerves, of epileptiform attacks, of headache, and eye symptoms which have disappeared under treatment, should be sought out. It is not well to give too much credence to the stories of patients, who are not always willing to admit their past lapses from virtue; but, on the other hand, the plan of suspecting everybody who presents advanced cerebral symptoms is often a grievous wrong. Not infrequently external cranial nodes are present in cases of intracranial syphilis.