Role of MR imaging in diagnosis and staging of renal cell carcinoma

ABSTRACT

Twenty sex patients with renal masses diagnosed by ultrasonography and/or CT and highly suspected to be renal cell carcinomas, underwent pre-operative MR imaging to assess the value of MR in diagnosis and staging of renal cell carcinoma. Renal lesions in all the studied patients were examined histopathologically and proved to be renal cell carcinomas. Renal ceil carcinoma had a varied MR signal, the most common appearance being a mass with an intensity intermediate between renal cortex and medulla on Tl-weighted images in 15 patients and heterogeneous intensity on T2-weighted images in 16 patients, The renal masses showed enhancement in 23 patients [homogeneous in 4 patients and heterogeneous in 19 patients] and in 3 patients no enhancement was detected on post-contrast Tl -weighted images. MR staging revealed stage I in 12 patients, stage II in 6 patients, stage III in 6 patients [stage IIIa in 3 patients, stage IIIb in 2 patients and stage IIlc in one patient] and stage IV in 2 patients [stage I Va in one patient and stage IVb in one patient]. Accurate MR staging detected in 23 patients [88% accuracy], in the other 3 patients, the MR stage changed by surgical and pathological findings from stage I into stage II in 2 patients [due to presence of microscopic perinephric fat involvement] and from stage IIlb into stage II in one patient [because of the enlargement of the para-aortic lymph node was found to be reactive, no malignant infiltration detected in the lymph node], MRI showed venous invasion clearly without need for intravenous contrast medium with 100% sensitivity. MRI is an excellent modality in preoperative evaluation of renal cell carcinoma