Cutaneous metastases of internal cancer

Background Cutaneous metastases of internal malignant tumors are rare. Though, they sometimes reveal the first manifestation of a malignant tumor. Methods The histopathologic files of two years in two German departments of dermatology (one in Thuringia, one in Saxonia) were investigated for histopathologic evidence of metastatic spread of internal cancer to the skin. Clinical and histologic data were collected. Outcome was evaluated. Results We observed 11 cases of cutaneous spread of internal cancer. Primary tumors were breast, lung, and GIT cancer in 8 cases, and renal carcinoma, gallbladder carcinoma, and thyroid follicular carcinoma in one case each. Preferred sites were the head and neck region and the trunk, but one tumor was seen on the lower leg. The incidence of cutaneous metastasis due to internal cancer was estimated as 4/8,000-10,000 a year. The cutaneous spread is often a sign of poor prognosis since 3 of 11 patients died within the short mean follow-up of 7.5 months. Conclusions Despite the fact that cutaneous metastasis of internal cancer is a rare event, one should be aware of it. It seems to be a sign of poor prognosis. A new and rapidly growing tumor on one of the above mentioned sites is suspicious for a cutanous metastasis. A diagnostic biopsy is recommended in cases where a complete excision is not possible. A B S T R AC T