Patterns of skin metastases: A review of 25years' experience at a single cancer center

Background Skin metastases can be defined as the spread of a tumor from its site of primary origin to the skin. Skin metastasis may be the first sign of advanced cancer or an indicator of cancer recurrence. Objectives To review patient data of 401 skin metastases available from our institution and compare this information to previously published studies. Methods Patient data from the Cancer Registry at RPCI database was reviewed for skin metastasis using vendor software. We included all cases of carcinoma, melanoma, sarcomas, and hematologic malignancies entered during a 25-year period from January 4, 1985, to March 1, 2010. Data identifying the relationship of tumor incidence, morphology, and skin metastasis was reviewed. A total of 401 patients who had skin metastases at the time of cancer diagnosis or had skin metastases as a recurrent site were included in this study. Extensive literature review was conducted using PubMed for articles relating to skin metastases and its clinical presentation and histological features. Results Breast cancer was the most common cancer to metastasize to the skin (32.7% of all skin metastases seen) followed by bronchus and lung (13.2%), skin (melanoma; 9.5%), lymph nodes (7.5%), oral cavity/pharynx/larynx (6.2%), blood and bone marrow (5.5%), and colorectal (4.2%). The most common histological types of tumors were identified as adenocarcinoma (infiltrating ductal carcinoma [22.7%]), lobular carcinoma (4.7%), and non-adenocarcinoma (squamous cell carcinoma [12.2%] and malignant melanoma [5.2%]). Conclusions This is the largest review of skin metastases in the United States in the past 25 years. We found the primary cancers that metastasize to the skin have changed in frequency from previous studies. Our data are helpful in indicating which cancers have the strongest predilection for skin metastasis. Identification of these cancers can help both the clinician and patient detect early signs of metastases, which may allow for earlier diagnosis, implementation of therapy, and possible prolonged survival.