neighboring tissues occurs only when the tumor has passed its bony confines. This may take years. As a rule, these tumors are confined to the parts from which they originate for a considerable time. During this period removal of the tumor alone is often sufficient to effect a cure.
Lymphatic involvement is the exception. In quite a considerable number of cases the inguinal and femoral glands are enlarged, but, as a rule, no sarcomatous change is found in them on microscopic examination. Metastases occur late in myeloid tumors. In the calcifying and ossifying giant-celled sarcoma, metastasis occurred in 58 per cent. of the cases reviewed by Gross.
The clinical picture presented in giant-celled sarcoma is usually that of the slow growing regular, spherical, more or less firm tumor involving one of the extremities, usually the lower of the femur. The tumor mass is incased in a bony capsule for some time. As the capsule becomes thinned, crepitation on the slightest pressure is observed. In extremely vascular tumors, pulsation may be a prominent feature. Even in cases where no great enlargement of the vessels is found, pulsations may be an early symptom.
On section, the tumor appears as a soft mass of deep red color, having the consistency of muscle tissue. Occasionally the color varies from light brown to yellow, depending upon the amount of fibrous tissue and upon the degenerative changes present. In vascular tumors extensive blood cysts may be found. In the calcified and ossifying tumors, hard masses and sharp bony spicules can be seen and felt on the cut surface. The skin covering these growths usually remains unchanged. In but few are the subcutaneous veins enlarged or the surface ulcerated. Their growth is usually progressive. Occasionally, it is temporarily arrested, as in the case recorded by Hutchinson, in which a giant-celled sarcoma, after having reached the size of a child’s head in fourteen months, ceased to develop for four years, when, without any apparent cause, it rapidly grew until a fatal termination ensued. Certain conditions, such as trauma, pregnancy and laceration seem to stimulate them to increased activity. Pain, though not a constant symptom, usually is present. Gross states that it is a prominent feature in about 50 per cent. of the cases. In the majority of cases, the neighboring joint is not involved until very late in the disease, the articular certilage offering considerable resistance to the growth of the tumor into the joint.
Fracture of the bone through the tumor occurs frequently and often first directs the patient to a surgeon. These tumors occur
