Renal tubular dysgenesis-like lesions and hypocalvaria. Report of two cases involving indomethacin.

We describe a case of twins with twin-to-twin transfusion syndrome (TTS) who were found to have renal tubular dysgenesis (TRD)-like lesions and hypocalvaria attributed to indomethacin treatment of the mother for acute polyhydramnios. History of pregnancy, postnatal clinical course, pathological findings of the kidneys, and the skulls are presented and discussed. These findings include incompletely differentiated proximal tubules in the kidneys and hypoplastic calvaria in both twins. The renal tubular lesions were more marked in the donor than in the transfused twin, probably due to the greater degree of ischemia in that twin. This seems to be in favor of a vascular etiology of the renal defects. However, the fact that similar renal lesions and hypocalvaria were also present in the transfused twin seems to indicate that indomethacin played a role in their onset. This so-called kidney-skull connection has never been reported in conjunction with indomethacin therapy.