Bilateral adrenal neuroblastoma

Background. Bilateral adrenal neuroblastoma is extremely rare. To date, 45 cases have been reported in the literature. Procedures. We retrospectively identified and reviewed 15 cases of bilateral adrenal neuroblastoma, treated between 1988 and 2004, by the French Society of Pediatric Oncology. We then compared our cohort to the 45 cases reported in literature. Results. Median age at diagnosis was 4 months in our cohort whereas it was 3 months in the literature. The same percentage of infants was found in both series (86.6%). Disease had generally been detected due to metastasis-related symptoms. Ten out of 15 patients in our cohort and 18/39 cases in the literature were classified as stage 4S according to the International Neuroblastoma Staging System (INSS). The incidence of stage 4S was significantly higher than that described in other neuroblastoma cohorts (P = 10^-4). Five-year overall survival was 90% for stage 4S. In our series, bilateral neuroblastoma was neither associated with familial cases nor with any risk factors. Conclusions. The majority of bilateral neuroblastoma carry a favorable prognosis. Exceptional cases exhibiting risk factors, such as amplified MYCN, are comparable to high-risk unilateral neuroblastoma cases with the same poor prognostic features. The therapeutic strategy could be similar to that used against unilateral neuroblastoma, except for surgery. However, the low incidence of relapse and the risk of adrenal failure if radical surgery is performed, argue against an aggressive surgical approach.