[Synchronous colorectal and renal tumors: two case reports].

The simultaneous presence of more than one primary malignant tumour in the same patient is a relatively rare event, with values going from 2.7% to 6.8%. In this paper two synchronous colorectal-renal cases surgically treated are described; in the first case with only one resolutive operation for the two tumours, in the second with two consecutive operations. In both cases, the patients had no familiarity for colorectal or renal malignant tumours. Both cases have paradigmatic peculiarities: in the first the discovery of the renal neoplasm has been possible in election during the normal execution of the diagnostic protocol for sigmoido-rectal neoplasm. The second case shows the other possible modality of the outset of the two tumours: the occlusive urgency which never allows to discover immediately the renal tumour (unless a laparotomic exploration makes it perceptible).