Evaluation of fine-needle aspiration cytology for renal masses

Objective To evaluate the accuracy and use of fine-needle aspiration (FNA) cytology fur the diagnosis of renal masses because with the improved qualit y and increasing use of ultrasonography and computed tomography (CT), asymp tomatic renal masses, particularly small (< 5 cm) tumours, are being discov ered more frequently. Patients and methods Between 1995 and 1997, 49 patients (mean age 67.5 year s, range 42-88, 34 men and 14 women) underwent FNA of a solid or complex cy stic mass under radiological guidance. All masses were further evaluated an d staged by CT. Solid masses were divided according to size ( < 5 fm and gr eater than or equal to 5 cm). Patients were followed up to the determinatio n of a final diagnosis on tissue histology, after nephrectomy where possibl e. Results Thirty-six patients had histologically confirmed carcinoma at nephr ectomy, and nine had presumed carcinoma (four unfit for surgery, five with advanced malignancy). The remaining four patients had benign diagnoses. FNA produced insufficient sample in eight cases (16%). The sensitivity was 89% for large (greater than or equal to 5 cm) solid masses, 64% for small (< 5 cm) solid masses and 50% for complex cysts. Conclusion FNA does not: contribute to the diagnosis of malignancy in large (> 5 cm) masses, as good radiological imaging is nearly always diagnostic. For smaller (< 5 cm) masses and complex cysts, FNA can occasionally confir m malignancy, but lack of diagnostic yield and low sensitivity means that F NA is unreliable as a diagnostic tool and will rarely help in the routine m anagement of these patients.