[Case of sarcomatoid renal cell carcinoma developed in the chalked kidney (putty kidney)].

A 66-year-old woman, who developed pulmonary tuberculosis at 17 years old, had a high fever in December, 2006. Computed tomographic (CT) scan showed a tumor in the left chalked kidney, which measured 7 cm in diameter with very low enhancement. Laboratory data showed the rise of acute phase reactants (erythrocyte sedimentation rate and c-reactive protein) and severe anemia. The cultures of sputum and urine revealed no Mycobacterium tuberculosis. With the diagnosis of left renal cell carcinoma in the chalked kidney, we performed left radical nephrectomy. Histopathological diagnosis was sarcomatoid renal cell carcinoma. Although sarcomatoid renal cell carcinoma is highly malignant and its prognosis is poor, her post-operative condition has been good without any adjuvant treatments and there have been no recurrent or metastatic lesions for 9 months. The supervention of renal cell carcinoma on renal tuberculosis is rare. The possible effects of tuberculous lesions on the development and progression of renal cell carcinoma are discussed.