Filling of the obturator nodes in pedal lymphangiography: fact or fiction.

The value of pedal lymphangiography as a staging procedure for carcinoma of the prostate and the bladder continues to be debated because of the fact that the obturator lymph nodes apparently are not visualized during this diagnostic technique. This study involves 25 patients who have undergone pedal lymphangiography followed by fine needle aspiration. Pelvic lymph node dissection was performed and pelvic x-rays were taken once the external iliac nodes had been excised, leaving the obturator nodes behind. The next step was the removal of the remaining nodes in the obturator fossa, after which another x-ray was obtained. With this technique we could prove whether these obturator lymph nodes opacified on routine pelvic x-ray. In a review of the radiography consistent filling of the obturator nodal chain was noted in all of the cases, as well as the consistent prediction of the location of these lymph nodes before fine needle aspiration.