in the structure of a bone, accompanied with the deposition of a morbid sarcomatous substance internally. This morbid change appears to be the consequence of inflammation, and its origin is frequently attributed to some mechanical injury or local irritation. In the commencement of the disease, the bone is slightly enlarged, perhaps somewhat thickened in its outer laminæ; and on a section of it being made, is found to contain a brown fleshy substance instead of its cancelli. This appears to be formed in consequence of a morbid action, perhaps inflammatory, of its internal structure. By the pressure of the new formation, the parietes of the bone are pushed outwards, in some cases attenuated, in others thickened by deposition of new osseous matter, inflammatory action having been induced by the pressure. As the internal formation increases, the parietes are extended, and are generally much attenuated, becoming in some places thin as paper, and diaphanous; they also would seem to lose a portion of their earthy matter, for they are flexible, somewhat elastic, and not of their usual density. Frequently they are in several places deficient, and their situation occupied by a membranous expansion, sometimes thin and delicate, but mostly thick and ligamentous; in some cases, the external lamina appears to be converted into a substance resembling the internal growth, with which it is continuous. The investing periosteum is much thickened, and its bloodvessels are enlarged. Occasionally, the deficiency of the bone is not supplied by any membranous expansion, and the morbid growth protrudes, fungous. The internal structure varies much in appearance; generally it is brown and soft, in some places broken down and mixed with a dark-coloured fluid, or with gelatiniform matter; sometimes it is much more dense, and resembles cartilage; in others, the cavity contains an ichorous fluid, mixed with small portions of more solid matter; in the advanced stage of the disease, the contents are often of the encephaloid nature, either in its homogeneous and solid form, or softened, broken down, and mixed with blood, or with a lard-like substance. Sometimes the cancelli of the bone are not destroyed, but extended, forming numerous cavities of considerable size, in which the morbid matter is deposited; in other instances, there is no appearance of cancellated structure, and the diseased mass contains rough osseous spicula, some detached, some loosely connected
with each other, and others projecting from the inner surface of the bony parietes of the tumour. At the commencement of the disease, the patient feels acute pain in the part, the constitution is disturbed; afterwards, the pain becomes more dull, and there is a considerable swelling externally, which feels hard, and slightly elastic; in the advanced stage, the pain again becomes severe, and is of a lancinating kind, and the system is much deranged, the tumour is softer, often presents a sense of distinct fluctuation, and on being freely handled, is found to crepitate, in consequence of the loose spicula of bone rubbing upon each other. Ultimately, the integuments become tense, livid, or dark-red, ulcerate, and allow a portion of the softened tumour to protrude, in the form of a frightful fungus; there is profuse discharge, thin, and sometimes bloody; there is much constitutional irritation, and the patient is greatly exhausted. Not unfrequently, during the progress of the disease, especially in the long bones, fracture occurs at the diseased part, either from external injury, or sudden muscular exertion. This occurred in the case from which the specimen here delineated was obtained some months before the patient submitted to amputation. The morbid structure had not broken through its periosteal investment. The muscles and their interfilamentous tissue were sound. The patient remained free from any return of the local disease. Bones so affected, when broken, do not unite, the movement of the loose and rough ends is a cause of much irritation: inflammatory action is kindled in the morbid structure, suppuration occurs, the integuments give way, and ulcerate to a greater or less extent, and the advancement of the disease is thus much hastened. The tumour may be safely pronounced malignant; it is true, that for some time it shows no tendency to involve the adjoining soft parts, further than by the effects of inflammation induced by its pressure; but then it is limited by the external lamina of the bones, which confines it to the tissue in which it originated; but after this barrier has given way, the tumour projects through the aperture, contaminating the adjacent soft parts, imparting to them a morbid action, and extending also in the cancellated tissue of the shaft of the bone. In some cases, the integuments are tense and discoloured, with large vessels running on their surface; the tumour feels soft and fluctuating, though the skin may not ulcerate till long afterwards. Perhaps the most common seat of this disease is the under-jaw, but it may occur in any of the bones; when it has been of chronic duration, not one bone but several are affected; and in one case which I saw, the disease commenced in the under-jaw, which it deformed to a frightful degree; almost every bone in the body was similarly, though less extensively diseased; this could be readily observed during the life of the patient, and was confirmed by dissection. From this, it appears, that the affection is not only dependent on local causes, but connected with a morbid state of the constitution, predisposing to it, and cooperating with its exciting cause.
There are other tumours of bones in some degree resembling, which do not strictly come under the term Osteosarcoma. Some are wholly cartilaginous, the disease commencing in their centre, and involving their entire substance, emitting a gelatinous fluid when cut, but containing no cells; others are not uncommon, partly osseous, and partly cartilaginous, containing cells filled with a glairy fluid; others are composed of cartilage, intersected with dense fibrous matter, in a greater or less proportion. In fact, the individual tumours of bones vary as much from one another as those of the softer tissues; scarcely two are alike in their progress, action, or anatomical characters. Irregular spicula of bone are found in many parts of their structure; in the same way that portions of bone often exist in tumours having no connection with the bones; in many places they are softened and broken down, the partitions between the cells are destroyed, and these contain a pulpy mass of a dark sanious appearance. On making a section, they are observed to be continuous with the interior of the bone, which is converted into a substance similar to themselves, or is of a more soft and medullary character. The external surface becomes tuberculated, the integuments are painful, and changed in appearance; they ulcerate, the tubercles burst, the discharge is thin and bloody, the ulceration extends; not unfrequently a fungus protrudes, and occasionally bleeds; this may slough, the tumour becomes farther exposed, portions of it die, and are discharged, unhealthy fungous granulations project from amongst the cancelli of the tumour, and emit a sanious putrid discharge, often bloody; severe constitutional irritation accompanies this state, the patient becomes hectic, is much exhausted, and sinks, unless the morbid parts be removed. There are also tumours of bones, composed partly of cartilaginous or fleshy, or partly of osseous matter, arising from the periosteum and outer shell of the bone, and these often acquire a great magnitude before the diseased mass reaches the interior or medullary part of the bone.
SPINA VENTOSA.
By this term is understood a mere expansion of a bone from a collection of matter in its substance. The disease may be produced by external injury, exciting inflammation, and consequent suppuration, in the cancellated tissue; or in a weakened and unhealthy constitution, the action may be of a chronic nature. The fluid accumulates, the cancelli are broken down, and the much-attenuated parietes of the bone are pressed outwards. Occasionally inflammatory action is excited on the external surface, from the pressure of the contained fluid, and minute nodules of bony matter are effused, as if nature endeavoured to strengthen those walls which are daily becoming thinner, and more incapable of supporting the weight of those parts which they encircle. The disease differs from Osteosarcoma in the contents being uniformly fluid, generally purulent, though often mixed with more liquid and dark-coloured matter, or with a curdy substance—in the gradual extension of the bone—in no fungus protruding after a portion of the attenuated bone has given way, matter being discharged as from a common abscess; and in the tumour not possessing a malignant disposition. At first there is considerable pain in the part whilst the matter is forming, but afterwards it becomes much less acute, and in many instances there is no inconvenience, except from the bulk of the tumour. Often after having reached no very large size, it becomes stationary, neither recedes or enlarges, and all painful sensations cease; in other cases it enlarges gradually, attains an enormous size, and produces much disturbance of the constitution; but in such instances the patient is generally weak and cachectic. The largest tumour of this species which I have seen, occurred in the lower part of the femur. It measured, in breadth, seven inches, in length, seven and one-fourth. The parietes were composed of an extremely
