Pregnancy with fetal brain tumor

Abstract

Fetal intracranial tumors are exceptionally rare, occurring at an overall incidence of 0.34 per one thousand live births. As per the 2016 classification of central nervous system tumors, primitive neuroectodermal tumors (PNETs) are categorized as highly malignant embryonal tumors in WHO Group IV. This case involves a 29-year-old in her third pregnancy, with two previous uneventful term deliveries. At 27+3 gestational weeks, she sought care at the University clinic due to fetal hydrocephalus. An ultrasound at 28 gestational weeks revealed a heterogenous, tumor-like mass measuring 70x66mm in the right brain hemisphere. The fetal head exhibited a whole dilated right ventricle (26mm posterior horn dimension) with a leftward shift of the cerebral falx. Subsequent fetal MRI demonstrated a partly solid, partly cystic tumor with a heterogenous appearance in T2 pulse sequence, extending in a frontoparietal direction. The differential diagnosis included glioblastoma. Following comprehensive scans, the parents were informed of the potential outcomes. The newborn, unfortunately, did not survive, weighing 1700g and measuring 42 centimeters. Pathological evaluation identified a primitive neuroectodermal tumor in the right parietal lobe, accompanied by internal hydrocephalus and cerebral encephalomalacia. Microscopic examination showcased Homer-Wright rosette formations, consisting of moderately differentiated round to oval cells with eosinophilic to amphophilic cytoplasm and hyperchromatic nuclei surrounding a central core of neurofibrillary material. Immune histochemical staining confirmed the tumor's profile, including Vimentin(+), S100(+), GFAP(+), Actin(-/+), Desmin(-), CD99(-), EMA(-), CKWS(-), Chromogranin(-), NSE(+), WT1(+), and Synaptophysin positivity in single cells with dendrites. The proliferative index stood at 2-3%. In summary, this rare case emphasizes the challenges of antenatal PNET diagnosis, with only 18% identified before or at delivery among tumors presenting in the first year of life.