Histopathologic findings of advanced neuroblastoma after intensive induction chemotherapy.

Background: Histopathologic findings of advanced neuroblastoma after intensive induction chemotherapy have not been studied well.
Methods: In the present study, all of the surgical specimens from 19 patients who had advanced abdominal neuroblastoma and were pretreated intensively with the protocol of the Study Group of Japan were reviewed. The authors found that dissection of the contralateral lymph nodes is mandatory in advanced neuroblastoma when the goal is the complete dissection of the abdominal disease. Effects of chemotherapy were graded histologically according to the ratio of viable residual neuroblastoma tissue to total areas of the tumor, including neuroblastoma, ganglioneuroblastoma, ganglioneuroma, hemorrhage, necrosis and fibrosis, in five ranks from ( ) to (-).
Conclusions: The newly introduced, highly cytotoxic regimen of the Japanese protocol, designated "A3," appears to be more effective histologically than the conventional regimen, designated "A1" or "new A1." Effects designated ( ) or (++) were prerequisites for survival in stage IV disease, but some stage III patients with the (+) effect survived.