CARCINOMA IN A TRANSPLANTED KIDNEY DETECTED WITH MAG3 SCINTIGRAPHY

We report on two cases of infiltrative renal tumor developing in two k idney transplant recipients from a single cadaveric donor source. Inte restingly, while this is only the second case of a de novo renal allog raft tumor, both were morphologically infiltrative. The fact that both tumors were infiltrative may be secondary to immunosuppression therap y. While computed tomography (CT) evaluation of suspected renal pathol ogy provides excellent anatomical detail, renal transplant recipients are initially evaluated using ultrasound and renal scintigraphy to avo id contrast reagents which could further impair renal function, as wel l as to reduce the image procedure cost and the patient radiation dose . Unfortunately, infiltrative tumors may be isoechoic on ultrasound, p roviding a confusing or conflicting report when compared to scintigrap hic findings. This case report is significant radiographically because the original neoplasm was initially detected using technetium-99m-lab eled mercaptoacetyltriglycine (Tc-99m-MAG3) scintigraphy and was not a ppreciated by sonographic studies, even retrospectively. This case dem onstrates the usefulness of Tc-99m-MAG3 scintigraphy to follow-up eval uations of renal transplants by providing detailed anatomical informat ion as well as functional analysis of the kidney.