A Roentgen Study of Bone Metastases from Melanoma

Abstract

Some cancers have known proclivities to metastasize to specific organs as determined by the route of dissemination and by the unexplained phenomenon of selective localization. Malignant melanomas are known to disseminate widely, but the extent and incidence of visceral involvement have not been fully appreciated. In the course of treating more than 1,300 patients with malignant melanoma, the Mixed Tumor Service of Memorial Cancer Center (New York) has had a unique opportunity of analyzing the distribution of metastases as determined by postmortem examination. The incidence of metastatic involvement of various organs and tissues is illu strated in th e accomp anying diagram (Fig. 1). From a study of this scattergram it may be seen that there is no cancer so commonly inclined to widespread dissemination. For example, in proportion to frequency of occurrence, melanoma involves the brain (38 per cent) more often than any other cancer, exceeding even bronchogenic and mammary cancer. Forty-four per cent of patients dying of malignant melanoma have metastatic deposits in the heart, which is a greater incidence of involvement than obtains for any other neoplasm, even rhabdomyosarcoma and liposarcoma, which are known to disseminate to the heart with some frequency. Forty-nine per cent, or practically one out of two patients dying of melanoma, have bone metastases. The great majority of these metastases are silent or obscured by other symptoms and signs predominating in the terminal stages of the disease. The purpose of the present communication is primarily to discuss the radiographic manifestations of metastatic melanoma of bone. Although such metastases are not frequently encountered by the roentgenologist, it is still necessary for him to be generally acquainted with the appearance that these deposits may present on the radiograph. A survey of the scanty literature dealing with the roentgen findings in this condition revealed several reports, all of which, however, were based on relatively few patients. The most recent, by Wilner and Breckenridge (1), included.) cases in which they characterized these metastases as predominantly osteolytic. They also summarized the pertinent literature and cited 12 cases having depend able roentgen evaluation of the bone lesions, all of which were described as being largely osteolytic (2–5). From the considerable volume of melanomas of the Mixed Tumor Service of the Memorial Cancer Center, 3:3 cases with bone metastases having adequate x-ray film coverage were studied. This provides a sufficient basis, it is believed, to establish the roentgen characteristics of such metastases. Pathological proof was obtained for each tumor but, of course, not every individual bone lesion was proved histologically. In no instance, however, was a second neoplasm known or suspected.