Surgical management of cellular congenital mesoblastic nephroma in a neonate: a case report and review of literature

Background Congenital mesoblastic nephroma (CMN) is the most common type of renal stromal tumor in neonates. It is classified into cellular, classical, and mixed types. The multidisciplinary management approach is the mainstay of management. We are reporting a case of neonatal congenital mesoblastic nephroma in a full-term boy with intrauterine growth restriction and hypertension managed effectively in our institution. Case presentation A full-term boy with intrauterine growth restriction (IUGR) with a birth weight of 2.3 kg, referred at birth with an abdominal mass. His antenatal scan at 35 weeks showed a cystic abdominal mass. On delivery, a huge visible abdominal mass of cystic consistency and smooth surface was noticed at the right side of the abdomen. blood pressure was 98/75 mmHg. It was responsive to hydralazine. Aldosterone and renin were significantly elevated at more than 100 and 500 ng/dl, respectively. Serum neurone-specific enolase (NSE) was 35 ng/ml while alfa feto protein was (AFP) 50,000 kIU/L. An abdominal ultrasound scan revealed an ill-defined large heterogeneous mass of 6.09 × 6.5 × 5.77 cm that arises from the right kidney. A computed tomography scan confirmed a right kidney mass with peripheral claw sign of the normal right renal tissue. It was crossing the midline and causing a mass effect on the adjacent structures. The right renal artery and vein were compressed and shifted posteriorly and inferomedially. Right radical nephrectomy was performed via a right lower transverse incision. The tumor was completely excised with a tumor weight of 270 g and a size of 10.5 × 8 × 5.5 cm. Histopathological diagnosis was mesoblastic nephroma of a cellular type which was confirmed by immunohistochemistry. Post-operatively, the blood pressure has significantly reduced and antihypertensive medications were eventually weaned off. The multidisciplinary team decided to preserve chemotherapy only in case of recurrence. At 3 months follow-up, no features of recurrence were noticed based on surveillance ultrasonography. Conclusion Mesoblastic nephroma should be considered in any newborn with renal mass. The multidisciplinary team approach with aggressive management of hypertension, detailed radiological investigation, and complete tumor resection is fundamental for obtaining an excellent outcome for such entities.