Assessment of asymptomatic space occupying lesions of the kidney.

Space occupying lesions in the kidney are often reported as an "incidental finding" at I.V.P. Of 152 patients with expansive renal lesions, 94 could be classed as "incidental" and were found to consist in the main (92%) of benign cysts or other innocent tumours. Continued investigation is essential to obtain an accurate diagnosis. Renal angiography, usually performed first, not only craves extensive resources, but is painful, expensive and seldom gives a definite diagnosis in cases with cysts without supplementary aspiration-cytology and cystography. When the I.V.P. finding was incidental, angiography was conclusive in 82% and cytological aspiration in 96%. Renal angiography should be used only under definite circumstances, i.e. when I.V.P.-tomography suggests malignancy, for all tumours in the renal hilus and for those inaccessible to aspiration-biopsy. In all other cases where the original X-rays are strongly indicative of a cyst, an aspiration-biopsy with cytological examination of the aspirate and double-contrast-cystography should be performed initially, whereby the diagnosis of benign cyst could usually be confirmed, thus saving the trouble and expense of renal angiography.