Malignant Tumors of the Spine
MULTIPLE MYELOMA (MM)/SOLITARY PLASMACYTOMA
This malignant process is the result of abnormal growth of a certain blood cell called a plasma cell. It occurs most often in patients in their 50s or 60s and affected men and women equally. The annual incidence is approximately 2-3 per 100,000. There are specific x-ray findings suggestive of MM, and the diagnosis is confirmed with both blood and urine tests and ultimately with a bone marrow biopsy. When diagnosed it is important to identify other organs that may be affected such as kidneys, peripheral nerves, blood calcium levels to mention a few. Occasionally a spontaneous epidural hematoma can occur which require surgery to take the pressure off the nerves. The primary cause of death is renal failure and infections. Surgery for multiple myeloma is reserved for cases with neurologic involvement or fractures causing instability. There is approximately 18% 5-year survival and median survival is 24 months.
Osteosarcoma has a predilection for patients younger than 20 with a slight male preponderance. When this lesion is suspected biopsy is required for diagnosis and wide resection is required followed by chemotherapy and radiation. Unfortunately this is a very aggressive tumor and survival rates are usually 6-10 months and failure is most commonly occurs due to failure in getting local control of the tumor. A secondary osteosarcoma also exists that arises from previously irradiated bone. This tumor usually arises in patients in their forties and fifties. Like primary osteosarcoma the outcome is poor with less than 5% 5-year survival.
Chondrosarcoma of the spine has a predilection for men and occurs most often in the middle to later years of life. Only 6-10% of all chondrosarcomas arise in the spine. 50% of patients have a mass felt by touch before the diagnosis is made. X-rays and MRI are a must to evaluate this tumor. Chondrosarcomas are unique in that they are resistant to radiation therapy and the mainstay treatment is surgical resection. The most important goal of surgery is obtaining margins of tissue around the tumor that are tumor free. Five-year survival rates are 21-55% with median survival rate of 6 years.
Ewing’s Sarcoma (ES) is a malignant round cell tumor with peak incidence in the second decade of life. It is twice as common in men and when the spine is involved it usually involves the sacrum (see anatomy). Pain accompanied by neurologic deficit occurs in 60% as the primary complaint. Biopsy is vital in the diagnosis of ES. Treatment usually involves chemotherapy and radiation. Surgery is reserved for those patients with spinal instability or neurologic deterioration. 5-year survival rate is 32-43% with a 31% recurrence rate after initial treatment.
Chordoma’s typically occur in patients in their 5th or 6th decades of life and is twice as common in men. 50% of these tumors arise in the sacrum and 35% at the base of the skull. Presenting symptoms are usually vague and diagnosis often made after MRI detects a spine lesion and a biopsy is performed. Wide surgical resection is the only chance for cure frequently followed by a course of radiation treatment. There is a 30-50% 10 year survival rate with a 64% local recurrence rate.