RESUMEN
OBJECTIVE: To report a new case with elevation of Ca 125 and hydronephrotic kidney without neoplastic disease, having special reference to clinical aspects. METHOD: The clinical history, anatomopathological and immunohistochemical findings are described. We performed a bibliographic review. We report the case of a 27 year-old female with the diagnosis of giant hydronephrosis and Ca125 elevation (313 u/ml hydronephrotic kidney urine and 112.3 u/ml serum). RESULT: She underwent a radical nephrectomy and Ca125 levels decreased. After 9 years the patient did not have any neoplastic disease and Ca125 levels are normal. CONCLUSIONS: The Ca125 rise with hydronephrotic kidney may be usual although there are not enough studies. We think that in patients with hydronephrotic kidney and malignant neoplasm the Ca125 antigen can lose sensitivity for the early diagnosis, staging and follow up of the malignant diseases.