C. T. criteria of the differential diagnosis in primary retroperitoneal masses

This personal series of 44 primary retroperitoneal masses (P.R.P.M.) studied by C. T. is analyzed. The reliability of C. T. in the identification (44/44), characterization (43/44) and origin evaluation (41/44) of P.R.P.M. has been absolutely satisfactory. In particular, those criteria of C. T. diagnosis which may be utilized in the evaluation of the origin of upper abdominal masses are thoroughly described. The evaluation of the involvement (non invasive; invasive) of adjacent viscera has been achieved in 22/38 P.R.P.M. verified at operation. The evaluation of tumour resectability has been less reliable due to the high incidence of under-diagnosis (60% in our personal experience). C. T. may be used in addition as an aid to different diagnostic techniques (percutaneous guided needle biopsy) or to therapy (drainage of retroperitoneal abscesses). C. T. is absolutely necessary in the follow-up of P.R.P.M. after surgery, radiotherapy or chemotherapy.