Congenital Mesoblastic Nephroma
General Information About Congenital Mesoblastic Nephroma
Mesoblastic nephroma comprises about 5% of childhood kidney tumors, and more than 90% of cases appear within the first year of life. It is the most common kidney tumor found in infants younger than 3 months. The median age of diagnosis is 1 to 2 months. Twice as many males as females are diagnosed. The diagnosis should be questioned when applied to individuals older than 2 years.
When patients are diagnosed in the first 7 months of life, the 5-year event-free survival (EFS) rate is 94%, and the overall survival (OS) rate is 96%. In a report from the United Kingdom of 50 children with mesoblastic nephroma studied on clinical trials and 80 cases from the national registry in the same time period, there were no deaths.
Grossly, mesoblastic nephromas appear as solitary, unilateral masses indistinguishable from nephroblastoma. Microscopically, they consist of spindled mesenchymal cells. Mesoblastic nephroma can be divided into the following two major types:
- Classic. Classic mesoblastic nephroma is often diagnosed by prenatal ultrasound or within 3 months after birth and closely resembles infantile fibromatosis.
- Cellular. A potential linkage between infantile fibrosarcoma and cellular mesoblastic nephroma is suggested because both contain the same t(12;15)(p13;q25) translocation, which results in the ETV6/NTRK3 fusion.
The risk for recurrence in mesoblastic nephroma is closely associated with the presence of a cellular component and with stage.
(Refer to the Wilms tumor Clinical Features and Diagnostic and Staging Evaluation sections of this summary for more information about the clinical features and diagnostic evaluation of childhood kidney tumors.)
Standard Treatment Options for Congenital Mesoblastic Nephroma
Standard treatment options for congenital mesoblastic nephroma include the following:
- A prospective clinical trial enrolled 50 patients with congenital mesoblastic nephroma.
- The results confirmed that complete surgical resection, which includes the entire capsule, is adequate therapy for most patients with mesoblastic nephroma.
- Only 2 of 50 patients died.
- Patients were at increased risk of local and eventually metastatic recurrence if there was stage III disease (incomplete resection and/or histologically positive resection margin), cellular subtype, and age 3 months or older at diagnosis. Because of the small numbers of patients and the overlapping incidence of these characteristics (5 of 50 patients), the significance of the individual characteristics could not be discerned.
Adjuvant chemotherapy has been recommended for patients with stage III cellular subtype who are aged 3 months or older at diagnosis. However, the benefit of adjuvant therapy will remain unproven with such a low incidence of disease. Infants younger than 2 months with incompletely resected, stage III disease may not need chemotherapy.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with congenital mesoblastic nephroma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
- England RJ, Haider N, Vujanic GM, et al.: Mesoblastic nephroma: a report of the United Kingdom Children's Cancer and Leukaemia Group (CCLG). Pediatr Blood Cancer 56 (5): 744-8, 2011. [PUBMED Abstract]
- van den Heuvel-Eibrink MM, Grundy P, Graf N, et al.: Characteristics and survival of 750 children diagnosed with a renal tumor in the first seven months of life: A collaborative study by the SIOP/GPOH/SFOP, NWTSG, and UKCCSG Wilms tumor study groups. Pediatr Blood Cancer 50 (6): 1130-4, 2008. [PUBMED Abstract]
- Furtwaengler R, Reinhard H, Leuschner I, et al.: Mesoblastic nephroma--a report from the Gesellschaft fur Pädiatrische Onkologie und Hämatologie (GPOH). Cancer 106 (10): 2275-83, 2006. [PUBMED Abstract]
- Vujanić GM, Sandstedt B, Harms D, et al.: Revised International Society of Paediatric Oncology (SIOP) working classification of renal tumors of childhood. Med Pediatr Oncol 38 (2): 79-82, 2002. [PUBMED Abstract]