Megacalices--how broad a spectrum?

Ten patients with a suspected diagnosis of megacalices have had pressure-flow studies to confirm or exclude obstruction. Eight had no evidence of obstruction and amongst these there were 2 patients with a non-obstructed megaureter. Two patients showed evidence of obstruction and remain a dilemma from a management viewpoint. If "megacalices" is used simply as a descriptive term, then the spectrum of disease is wider than previously suspected.