[Carcinosarcoma of the skin]

Carcinosarcoma of skin is a biphasic tumor composed of intimately admixed malignant epithelial and mesenchymal components. Various terms have been used to designate these tumors (metaplastic carcinoma, pseudosarcoma, spindle cell carcinoma, etc.). However, the histogenetic conception has changed and carcinosarcoma is currently regarded as authentic sarcomatoid carcinoma.

The authors report the case of a 32-year-old women initially presenting with a budding and ulcerating tumor at the site of an old cutaneous scar on the right leg. Histopathological and immunohistochemical evaluation led to a diagnosis of cutaneous carcinosarcoma. One month after treatment, the patient developed inguinal lymph node metastasis.

Our case and a review of other cases in the literature confirm the dual epithelial and sarcomatous phenotype of sarcomatoid carcinoma. Progressive transition between the cells of the two components on microscopic analysis and their positive immunostaining for anti-p53 antibody suggest a clonal origin of the tumor. The carcinomatous component seems to influence the course of the disease with the development of metastases, particularly at the lymph nodes. It thus seems advisable to combine lymphadenectomy with surgical tumor excision.