Cutaneous Metastases of Malignant Disease

Cutaneous metastases are important because of their accessibility, although less frequent than lymph node and organ metastases. T o ascertain their approximate frequency, cases of metastasis to the skin were selected from 2233 autopsies in which malignant disease was present, from the Huntington Memorial Hospital, New England Deaconess Hospital, Pondville Hospital, and Harvard Medical School, and from approxim~tely 80,000 surgical specimens of all kinds from the three hospitals. One hundred and eighty-one cases were originally diagnosed as metastatic tumor in the skin. Eighty-eight of these were discarded because of inadequate data, leaving a total of 93 tumors of all kinds, including surgical and autopsy specimens, nletastatic in the skin. In addition, 349 cases have been assembled from the literature. One hundred and fifteen of these were gathered by Suzuki (60) in 1918 and are incorporated in this material, even though many of the skin tumors were not biopsied. The cases selected for this study, with the exception of a few reported by Suzuki, were examined microscopically and the possibility of direct extension was excluded. One hundred and seventeen of the cases from the literature were autopsied. An exhaustive survey of the literature was not attempted. The cases in this paper represent rather a fair sample of the type of case with metastasis to the skin which is being reported constantly. The different types of malignancy producing skin metastases in this series are charted in Table I. Of 82,298 malignant and non-malignant specimens 93 (0.1 per cent) are metastatic malignant tumors localized in the skin: 29 (0.04 per cent) from 80,000 surgical specimens, and 64 (2.3 per cent) from the autopsy series of 2298 malignant tumors. The autopsy series probably represents more nearly the true frequency of occurrence, since many metastatic skin tumors may be unobserved or may not be diagnosed microscopically during life. There are iew adequate statistics on the incidence of metastatic tumors in the skin. My figures are considerably higher than others which have been published and approach those given by Nusbaum and Heyer (41) for metastases to the heart, which vary from 0.02 to 3.15 per cent. In Suzuki's article, various authors are cited as recording the frequency of secondary skin tumors from 0.01 to 0.7 per cent for all types of cases, malignant and non-malignant. In Table I1 the cases in this series plus those from the literature are classified according to the site of the primary tumor, the location of skin metastases, the age, and the sex of the patient. A little more than one-half or 58 of the secondary tumors of the skin in