Metastases to the kidney: eleven cases diagnosed by aspiration biopsy with histological correlation.

Metastases to the kidney from extrarenal primary tumors are uncommon and may mimic renal-cell carcinoma clinically when presenting as a single mass with hematuria. Fine-needle aspiration biopsy (FNAB) is a useful diagnostic method for the evaluation of primary renal tumors. Only a few studies have investigated the value of cytological evaluation of secondary renal tumors. We report our experience with these tumors. Eleven cases of extrarenal primary tumors metastatic to the kidney, diagnosed by aspiration biopsy with histological correlation, are discussed. The diagnosis of metastatic disease to the kidney was accurately made by aspiration biopsy. Knowledge of the patients' history, histological correlation with the primary tumor, and the radiological characteristics of the renal masses were helpful in achieving a correct diagnosis. FNA cytology (FNAC) is an accurate method for the diagnosis of tumors metastatic to the kidney. Distinction between primary and secondary tumors of the kidney is crucial to guide management and prevent unnecessary surgery.