Ultrasonography in tumors arising from the spine and bony pelvis.

Gray scale ultrasonography is a useful tool in evaluating pelvic and abdominal soft tissue masses that may be associated with bone neoplasms. Four patients are described: two with giant cell tumors, one with Ewing's sarcoma, and one with a sacrococcygeal teratoma. Ultrasound is especially helpful in assessing the extent of disease, treatment planning, and in following the results of therapy.