[Extra-abdominal spread of pelvic neoplasms. CT evaluation and radiotherapeutic implications]

Meyers and other authors have described the extra-abdominal spread of inflammatory abdominal diseases. Conversely, little attention has been paid to the extra-abdominal spread of pelvic neoplasms. The authors have detected, by means of CT, 17 cases of extra-abdominal neoplastic spread in a series of 203 patients with pelvic neoplasms. Neoplastic spread involved the inguinal region in 1 case, the buttock in 6 cases, and the ischiorectal fossa and/or perineum in 12 cases, with more than one region involved in some patients. In such cases CT showed the extension of tumoral tissue beyond the muscular walls of the pelvis. Recurrent pelvic carcinomas are the most common neoplasms spreading outside the pelvis. Surgical obliteration of the pelvic fasciae can explain such a behavior. Differential diagnosis is to be made with inflammatory pelvic diseases with extrapelvic spread. When a pelvic tumor spreads outside the pelvis it can be seen as a primitive gluteal or inguinal or perineal mass. CT demonstration of such an insidious event is mandatory for both a correct diagnosis and radiation treatment planning.