Sarcomatoid Carcinoma of the Kidney: A Case Report

Sarcomatoid carcinoma of the kidney is an uncommon tumor associated with a very poor prognosis. Because this tumor can be occasionally difficult to distinguish from renal sarcoma, immunohistochemistry and electronmicroscopy are sometimes necessary for diagnosis. Therapy is actually essentially surgical because if adjuvant therapies should follow radical nephrectomy, no standardized regimen has been at present defined. The patient was a 67-year-old, father of two, a chronic smoker who had quit smoking 3 years previously. Our patient had no comorbidities. The diagnosis of a kidney tumour was suggested by the image of an inferior polar process of the left kidney on the abdominal CT scan, revealed by abdominal pain. The patient underwent an enlarged total nephrectomy: in favour of a locally advanced sarcomatoid carcinoma of the kidney measuring 10 centimetres. The patient has been discussed at a multidisciplinary consultation meeting for systemic treatment in accordance with international recommendations. The mainstay of treatment is extended nephrectomy. Nephrectomy is not always feasible, and when it is, it appears that this operation has little influence on the survival rate and prognosis. After surgery, the average survival time is short, around 6.3 months on average. Surgery alone would therefore appear to be ineffective in aggressive behaviour of this tumour. Adjuvant treatment is needed to control the disease. Between immunotherapy, anti-angionogenic agents or chemotherapy, a few series in the literature have reported the benefit of these different molecules on the recurrence-free survival of these patients. The natural history of sarcomatoid carcinoma of the kidney is frightening. The poor spontaneous prognosis of this tumour is compounded by the absence of an effective therapeutic weapon. The key to treatment may lie in the development of molecularly targeted therapies.