Metanephric stromal tumor in an adult with PDGFRA mutation: a case report

BackgroundMetanephric stromal tumors (MST) are rare benign renal tumors that mainly occur in infants and children. Approximately 72% of MST in children have the B-Raf proto-oncogene serine/threonine kinase (BRAF) V600E mutation. To date, only five cases of adult MSTs have been reported and no clear genetic alterations have been found.Case presentationWe report a case of MST in a 45-year-old woman who complained of left lower back pain for a week, accompanied by hypertension (150/79 mmHg). Magnetic resonance imaging (MRI) showed an abnormally enhanced nodule (1.1 cm in the middle of the left kidney), which was histopathologically consistent with an MST. The BRAF V600E mutation was not detected in tumor cells using PCR and next-generation sequencing (NGS). However, a platelet-derived growth factor receptor alpha (PDGFRA) mutation was detected in this case using NGS. The patient showed no recurrence or metastasis nine months after partial nephrectomy, and her blood pressure was consistently normal.ConclusionThis is the first report of alterations in PDGFRA in MSTs. This result advances our knowledge of genetic variations in adult MSTs, which may have different gene alterations from MSTs in children.

Automated summary

This case report describes a rare renal tumor called metanephric stromal tumor (MST) in a 45-year-old woman. Genetic analysis revealed a mutation in the PDGFRA gene, but not the BRAF V600E mutation commonly found in pediatric MSTs. The patient had no recurrence or metastasis nine months after surgery and maintained normal blood pressure.