Background: Although multifocal neuroblastoma is rare, its incidence has increased because of recent improvements in diagnostic tools and the introduction of mass screening. Among the 106 neuroblastoma cases treated at the authors' hospital between 1984 and 1998, 8 were multifocal neuroblastoma.
Methods: The authors examined clinicopathologic findings and biologic features, including MYCN amplification, NTRK1 and Ha-ras p21 expression, cellular DNA content, and telomerase activity in these 8 multifocal neuroblastoma cases. Moreover, clinicopathologic findings were investigated with a review of 53 published cases of multiple neuroblastoma in the literature published in English between 1966 and 1999.
Results: Among these eight cases, five were detected by mass screening and three were incidental neuroblastomas. Histologically, all tumors were classified as ganglioneuroma or favorable neuroblastoma except one advanced case. All tumors lacked the MYCN gene amplification and expressed NTRAK1 mRNA and Ha-ras p21 protein. Cellular DNA content showed that half of these tumors were near-triploid, and the proliferative index (%S-phase) of all tumors was less than 25%. High telomerase activity was detected in none of these cases. Four patients underwent multistage operation and five patients with bilateral adrenal neuroblastomas underwent tumor enucleation to preserve adrenal function. Currently, all patients are disease free and none have required corticosteroid replacement therapy. Among the previously reported 53 cases with multifocal neuroblastoma, 25 were incidentally detected, 18 had familiar history, and most patients without other major complications also had extremely good prognoses.
Conclusions: These findings suggested that most multifocal neuroblastomas have favorable biologic features. Clinically, surgical approaches should be attempted to preserve organ function, especially adrenal function, and minimal invasive surgery should be performed. In cases of thoracoabdominal neuroblastoma, multistage surgery is effective and safe.
Copyright 2000 American Cancer Society.