Fatal presentation of congenital neuroblastoma with placental metastases: report of a rare case.

Congenital neuroblastoma is the most common malignant fetal tumor, yet placental metastases are exceptionally rare. We report a fetus with a right-sided suprarenal mass, hydrops, and marked placentomegaly that progressed to intrauterine demise at 26 weeks. Histopathology confirmed widespread metastatic neuroblastoma involving fetal organs and placental fetal vessels while sparing maternal intervillous spaces. This case is unique due to extensive involvement of placental fetal vessels with complete sparing of the maternal intervillous space. It highlights the importance of considering metastatic neuroblastoma when fetal abdominal masses coexist with hydrops and placentomegaly.