Abstract:

Objective The clinical characteristics, treatment strategies and clinical outcomes of congenital mesoblastic nephroma (CMN) were retrospectively analyzed and CMN diagnosis and treatment were summarized. Methods The age at onset, tumor size, pathological classification, ETV6-NTRK fusion gene, treatment regimens and clinical outcomes of children newly diagnosed with CMN admitted to the Department of Pediatric Hematology/Oncology, Xinhua Hospital from January 2013 to December 2020 were analyzed. Results A total of 5 children with CMN were admitted in 7 years, including 4 boys and 1 girl. The median age of diagnosis was 4.5 months (0.3-11 months). In 3 patients, renal mass was found during obstetric examination, and CMN was diagnosed early after birth, and ETV6-NTRK fusion gene was negative. The CMN diagnosis age was older than 6 months in 2 patients, and the ETV6-NTRK fusion gene was positive. The tumor stages were stageⅠ (1 case), StageⅡ (1 case), and stage Ⅲ (3 cases). Pathological classification was as follows: 1 case was classical, 2 cases were cellular (stageⅡchild with epithelioid type), and 2 cases were mixed. All the children underwent surgery. One child received surgical resection after 2 cycles of neoadjuvant chemotherapy. The stage Ⅲ children received 9 cycles of VAC chemotherapy after surgery. The median follow-up time was 19 months (11-34 months). One stageⅡchild relapsed 1 year after the completion of combined treatment with surgery and chemotherapy, while the rest of the children were disease-free. Conclusions Most children with CMN have a good prognosis after surgery combined with adjuvant chemotherapy. The age of diagnosis is generally less than 1 year old, and some children can be diagnosed early because of obstetric examination. Surgery is still the main treatment, and postoperative follow-up can be applied for stage Ⅰ and Ⅱ patients. Postoperative adjuvant chemotherapy can reduce the recurrence rate in stage Ⅲ cases.

Key words: congenital mesoblastic nephroma, ETV6-NTRK fusion gene, surgery, adjuvant chemotherapy