Analysis of cystic hygroma, ascitic, and pleural fluids by conventional lymphocyte culture and fluorescent in situ hybridization.

Serous fluids from cystic hygromas, pleural effusions, and ascites are an easily accessible and plentiful source of lymphocytes. The feasibility and reliability of using these as alternative sources to conventional amniotic fluid or fetal blood cultures have been studied here. In some cases of prenatal diagnosis, especially in pregnancies complicated by the presence of cystic hygromas and fetal hydrops, obtaining amniotic fluid or fetal blood can be difficult due to obstruction by the cyst or oligohydramnios. A total of 14 cases with fetal hydrops detected ultrasonigraphically between 15 and 33 weeks of pregnancy over a period of 1 year have been subjected to conventional amniotic fluid or fetal blood karyotyping, along with samples of fluids from cystic hygromas, ascites or pleural effusions as obtained. Pleural fluids (n = 4), cystic hygroma fluids (n = 5), and ascitic fluids (n = 6) were obtained. The culture failure rate was low, 2/14. Karyotypically, two of the fluids, both from cystic hygromas, were 45,X; the rest were normal. A rapid 1-day additional test of fluorescent in situ hybridization (FISH) was carried out on uncultured cells of the alternative fluids using probes for the most commonly occurring aneuploidies, 13, 18, 21, X and Y, with good results.