Metastasis of an undifferentiated fetal soft tissue sarcoma to the maternal compartment of the placenta: maternal aspects, pathology findings and review of the literature on fetal malignancies with placenta metastases

INI1 negative sarcoma diagnosed as malignant rhabdoid tumor presenting as hydrops fetalis metastatic to the placenta: a case report and review of the literature on congenital sarcomas

Rhabdoid tumor is a highly aggressive sarcoma found in young children that occurs in the kidney, central nervous system and soft tissue sites. Rarely, it presents in the fetus or neonate and is associated with a dismal prognosis. We report a case of a 28-week gestation fetus presenting with hydrops fetalis who died soon after delivery, found at autopsy to have a rhabdoid tumor of the thoracic cavity with placental metastases and provide a review of the literature of congenital sarcomas.

MYCN Amplified Relapse Following Resolution of MYCN Nonamplified 4S Neuroblastoma With Placental Involvement: A Case Report and Review of the Literature

Congenital neuroblastoma with placental involvement is exceptionally rare, but mortality is high. Detailed examination of placenta including MYCN amplification and segmental chromosomal aberrations should be performed in all suspected cases, as it is noninvasive and readily available. Maternal dissemination has not been reported. In this manuscript, we describe an infant with placental diagnosis of MYCN nonamplified congenital neuroblastoma. This is the first report of a recurrence of congenital 4S neuroblastoma following resolution in which MYCN amplification is only detected in the recurrence. Germline sequencing using a large comprehensive cancer panel did not reveal variants in candidate cancer predisposition genes.

Ultrasound Presentation of a Disseminated Fetal and Neonatal Rhabdoid Tumor

This is a case report of a disseminated fetal rhabdoid tumor discovered at 32 weeks of gestation in a 29-year-old woman on immunosuppressive therapy. The mother consulted for a decrease in fetal movement. Fetal ultrasound showed signs of a disseminated tumor affecting the left armpit, liver, spleen, and limbs. A caesarian section was performed because of signs of fetal distress. Immunohistochemical analysis of a fetal biopsy showed deletion of the SMARCB1 gene. Pathological analysis of the placenta showed a rhabdoid tumor invading both fetal and maternal compartments. The mother underwent a whole-body MRI, and no metastasis was found. To the best of our knowledge, this is the first report of a disseminated rhabdoid tumor invading both fetal and maternal compartments.