翁涵育、鄭鴻琳

 國立成功大學醫學院附設醫院泌尿部

Department of Urology, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan

 

Congenital mesoblastic nephroma (CMN), although a rare tumor, is the most common neonatal renal tumor which accounts for 3‑10% of childhood renal tumors. Currently, it can usually be detected antenatally with judicious and common use of ultrasonography. Surgical resection with nephrectomy is considered an adequate therapy for all subtypes. We reported a case of antenetal detection of renal tumor via ultrasonography and was diagnosed of congenital mesoblastic nephroma after radical  neprectomy when he was 8 days old.

A premature male infant was born to a G1P1, 31-year-old woman after 32+6 weeks’ gestation, which was complicated by polyhydramnios, detected on antenatal scan since 28 weeks. Later level II ultrasound further revealed fetal left renal mass, 6.4x5.9x5.2 cm in size. Preterm labor was noted at 31 weeks, followed by delivery by cesarean section due to progressive polyhydramnios after tocolysis for one more week. The baby was born in good condition, with Apgar scores of 9 and 9 at 1 and 5 minutes respectively. Birth weight was 1802 gm. Physical examination at birth was reported normal. On admission to the NICU, there were no cardiorespiratory concerns apart from an initial blood pressure of 75/36 mmHg. Abdominal CT showed left renal heterogeneous tumor involving upper and middle poles with perirenal fluid collection and enhanced Georta's fascia. There was no obvious intratumoral calcification or fat components. Operation as left radical nephrectomy was done and formal pathology confirmed the diagnosis of congenital mesoblastic nephroma.

CONCLUSION：

Despite being uncommon, CMN should be always taken into consideration when evaluating a fetal abdominal mass. Completeness of tumor resection is extremely important and is the primary treatment. Tthe overall prognosis of CMN is fairly good.