Lymphatic abnormalities in fetuses with posterior cervical cystic hygroma.

We studied the structure and number of lymph vessels in 12 spontaneously aborted previable fetuses with posterior cervical cystic hygroma and generalized edema of variable origin (monosomy X, trisomy 21, trisomy 13, suspected Noonan syndrome, and lethal multiple pterygium syndrome) and compared them to 5 therapeutically aborted, apparently normal fetuses. We found that in the non-45,X fetuses with cystic hygroma and edema the lymphatic vessels at all studied sites were dilated and appeared increased in number. The 45,X fetuses had no recognizable lymphatic vessels in the edematous cutaneous tissue of the limbs, and only occasional dilated vessels in the wall of the nuchal cystic hygroma and in the lungs. These findings may be useful in differentiating between monosomy X and other conditions causing nuchal cystic hygroma in specimens in which the fetus was incomplete and/or cytogenetic study could not be done.