[Perianal skin metastasis in a case of lung cancer].

A case of lung cancer in a 78-year-old man who subsequently developed a perianal skin metastasis is herein reported. The metastatic lesion was the fist clinical metastatic sign noticed. Although irradiation therapy reduced the size of the lung tumor, the tumor soon regrew and the patient died of massive hemorrhaging from the perianal mass. An autopsy revealed that the primary tumor and all metastases were, histologically, a mucoepidermoid carcinoma. A metastasis of a lung cancer to the perianal region is extremely rare, only one case involving an anaplastic carcinoma having been previously reported.