A Case Report on Congenital Mesoblastic Nephroma

Aims: This study aims to provide a comprehensive review of the epidemiology, genetic underpinnings, clinical presentation, and management strategies of congenital mesoblastic nephroma (CMN), with a focus on the diagnostic and therapeutic challenges that distinguish it from other neonatal renal tumors such as Wilms’ tumor. By presenting a unique case of a neonate diagnosed with CMN and undergoing tumor resection, we seek to highlight the complexities of perinatal care in such cases and the potential for life-threatening complications despite early intervention. Furthermore, the study underscores the importance of early and accurate differentiation between CMN subtypes, as well as the role of histopathology in guiding treatment approaches. Presentation of Case: A female neonate was born at 34+2 weeks gestation, presenting with a retroperitoneal mass on the left kidney, identified prenatally via ultrasound. Delivered by cesarean section due to polyhydramnios and anemia, a palpable intraabdominal mass was noted during examination. Imaging confirmed a heterogeneous solid lesion suggestive of nephroblastoma. The patient underwent nephroureterectomy, with histopathology confirming congenital mesoblastic nephroma. Despite successful resection, the patient died at 9 days of age from refractory catecholamine septic shock, with complications including neonatal sepsis, gastrointestinal bleeding, and femoral artery thrombosis. Discussion: Congenital mesoblastic nephroma is the most common renal tumor in neonates, often misdiagnosed as Wilms’ tumor. It typically presents before 2 months of age and is associated with translocation (12;15)(p13;q25). The prognosis for classical CMN is excellent, while the cellular variant is more aggressive. Surgical excision is the primary treatment, but the neonate's age necessitates careful management to mitigate risks. In this case, multiple complications contributed to the poor outcome despite timely intervention. Conclusion: CMN is a rare renal tumor in neonates, requiring accurate diagnosis through histopathology. While prognosis is generally favorable, complications from prematurity can adversely affect survival.