In the latest Case Record of the Massachusetts General Hospital, a 60-year-old man was seen in the outpatient cancer center because of bone pain that had lasted for 2 months and the presence of lytic bone lesions on imaging studies. Biopsy specimens of bone marrow and bone lesions showed increased mast cells. A diagnostic procedure was performed.
In general, bone lesions can be divided into two major types according to their radiologic appearance. Lytic lesions have a characteristic “moth eaten” appearance on imaging studies, which is caused by the juxtaposition of degraded bone and unaffected, calcified bone. The process of bone degradation is mediated by osteoclasts. In contrast, blastic bone lesions reflect increased bone formation, a process mediated by increased osteoblastic activity.
• What tumors most commonly metastasize to bone, and what are their radiologic characteristics?
The presence of multiple widespread bone lesions suggests a metastatic tumor; most common are lung or prostate cancer, renal-cell carcinoma, and melanoma. Tumors that metastasize to the bone often have characteristic biologic and radiologic characteristics; prostate cancer, carcinoid tumors, small-cell lung cancer, Hodgkin’s lymphoma, and medulloblastoma often cause osteoblastic lesions, whereas renal-cell carcinoma, non-small-cell lung cancer, thyroid cancer, melanoma, and lymphomas predominantly cause osteolytic lesions. Many metastatic tumors, particularly sarcomas and cancers of breast and gastrointestinal origin, may cause both lytic and blastic lesions. In general, the lesions can manifest in various ways.
• What are the clinical features of plasma-cell (multiple) myeloma?
Plasma-cell myeloma is characterized by an increase in clonal plasma cells in the bone marrow and the presence of a monoclonal paraprotein in the serum, as well as an associated abnormal calcium level and associated hematologic, renal, and bone abnormalities, including lytic bone lesions. A rare variant, nonsecretory myeloma, may occur, in which lytic bone lesions are present but a monoclonal paraprotein is not detected.
Morning Report Questions
Q: What are the characteristics of an epithelioid hemangioendothelioma, and how may it be treated?
A: Epithelioid hemangioendothelioma is a rare malignant tumor that affects fewer than 300 patients per year in the United States and accounts for approximately 1% of all vascular neoplasms. Clinically, it is treated as a low-to-intermediate-grade angiosarcoma because, as compared with high-grade angiosarcomas, metastasis is less likely to develop, disease progression or time to relapse is slower, and survival is longer, even in cases of advanced disease. Most epithelioid hemangioendotheliomas follow an indolent clinical course, but it is estimated that approximately 15% of patients with epithelioid hemangioendothelioma die of the disease. Because epithelioid hemangioendothelioma is a neoplasm of vascular origin, therapies that target angiogenesis in this disease were thought to be promising. Epithelioid hemangioendothelioma is known to express a wide variety of ligands and receptors for vascular endothelial growth factor (VEGF) isoforms. Several published case reports have shown a clinical benefit of the VEGF inhibitor bevacizumab. Other antiangiogenic agents have also been reported to show evidence of activity when they are administered as single agents. These agents include sunitinib, thalidomide, lenalidomide, and interferon-(alpha).
Q: How are painful bone metastases best managed?
A: In the management of painful spine metastases, the most important initial step is correctly identifying the cause of pain. Common causes of back pain that is associated with bone metastases are mechanical instability, tumor-related inflammation, nerve-root involvement, or a combination of these causes. Before initiating therapy for pain relief, cord compression requiring urgent surgical intervention must be ruled out. Augmentation, such as vertebroplasty and kyphoplasty, is minimally invasive and involves the percutaneous injection of acrylic cement (such as methyl methacrylate) with the use of imaging guidance. Randomized trials of augmentation involving patients with osteoporotic fractures have not shown any benefit. However, in selected cases of cancer-related fractures, augmentation has been associated with rapid and clinically significant pain relief. Pain that results from tumor-related inflammation (so-called biologic pain) is often unrelenting, subacute or chronic in onset, and responsive to glucocorticoids. Systemic therapy may offer pain relief in particularly responsive types of cancer. Radiation therapy is a common palliative strategy that offers partial pain relief in 50 to 80% of patients with tumor-related inflammation and complete pain relief in 20 to 40% of patients. Pain relief often does not occur until several weeks after completion of radiation therapy.