Bilateral adrenal neuroblastoma: clinical presentation, diagnostic and therapeutic approaches, treatment results

Bilateral adrenal neuroblastoma (BANB) is a very rare entity. It is more common in young children and has certain clinical features. Patients with BANB have a more favorable prognosis than patients with unilateral adrenal neuroblastoma (NB). The article presents an analysis of 29 cases of BANB in children who underwent treatment at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology, and Immunology. This study is supported by the Independent Ethics Committee and approved by the Academic Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology, and Immunology. The analysis was performed for the period from April 2012 to December 2018. Bilateral adrenal involvement was diagnosed on the basis of analysis/assessment of the results of all relevant imaging and instrumental tests. Additionally, we performed a retrospective analysis of the findings of computed tomography, magnetic resonance imagining, and scintigraphy with ¹²³I-metaiodobenzylguanidine (¹²³I-MIBG). In view of ¹²³I-MIBG scintigraphy sensitivity threshold, and in order to confirm the diagnosis, imaging findings were reviewed by an experienced radiologist. The patients received therapy in accordance with the risk-adapted NB-2004 protocol. Here, we analyzed the details of clinical presentation of the disease, age at the time of diagnosis, time from the disease onset to diagnosis, the presence or absence of life-threatening symptoms (LTS) and adrenal insufficiency, the aspects of patient management (including special aspects of surgical treatment), and treatment results. The median age at the time of diagnosis was 1.9 months. The patients were divided into 3 groups: children with localized BANB; children with true stage 4 disease; children with stage 4S disease. Most patients had metastatic NB, whereby stage 4S cases prevailed (55%, n = 16). Given the low sensitivity of MIBG scintigraphy for the detection of small tumours (less than 2 cm), one should use a comprehensive approach to the assessment of the results of imaging and instrumental tests in patients with BANB in order to confirm bilateral involvement. At diagnosis, about half of the patients with BANB (48%) had clinical symptoms associated with the presence of a retroperitoneal tumour mass and massive hepatomegaly because of liver metastases. Thirty-four percent of patients developed LTS. One of the typical features of BANB was the frequent development of adrenal insufficiency (in 41% of cases) caused by bilateral adrenal involvement, and this should be taken into account when performing diagnostic investigations and providing treatment to patients. Since bilateral radical resection is associated with the inevitable development of adrenal insufficiency, surgical treatment should be determined on an individual basis. Bilateral adrenalectomy is not generally recommended and can be undertaken after an interdisciplinary discussion in case of unfavourable course of the disease (e.g. in case of recurrence). Even if patients with BANB develop certain complications or events (progression) their prognosis is still good. The three- and five-year event-free survival rates in patients with BANB were 86 ± 6.4%. The three- and five-year overall survival rates were 100%. The analysis of patients with BANB showed that they have a more favourable course of the disease, and this may serve as grounds for assigning such patients into a special group. In view of the degree of tumour extension, the specifics of staging, and frequent development of adrenal insufficiency, standard check-ups should be complemented by endocrine monitoring, and surgical approaches should be chosen on an individual basis.