Tuesday, November 25, 2008

Choroid Plexus Cysts

“Are cysts a bad thing?” I asked the sonographer who was rubbing her instrument on Sally’s lubricated belly. She had been zooming in on pictures of various parts of our baby, who has 21 weeks of in utero growth under his or her proverbial belt. The sonographer had applied various labels to the pictures she was taking: leg, hand, heart, stomach. When she got to “cyst,” I asked the question off-handedly, without thinking how I would respond if she said “yes.”

“Not always,” the sonographer said. I immediately wanted to take off my coat, as the temperature in the room had suddenly jumped. Trying to joke, as is my custom, I said, “you know, I probably wouldn’t have asked that question if I thought you’d say that.” I moved away from the monitor, where I had been watching closely, to hold Sally’s hand.

Linda, the sonographer (who had a terrible head cold and paused now and then to cough up and spit out phlegm), said later in a sweet west Texas drawl, “I generally don’t say anything while I’m looking at something. And some people, it goes right over their heads; they don’t notice you paying particular attention to one thing or another. But if someone asks me, I’m not going to lie to ‘em and say there’s nothing there.”

“Not always” turns out to be “very rarely,” but we’re still shaken by these two symmetrical black dots in the cross-section of our child’s head. Linda described them as two choroid plexus cysts (abbreviated as “CPCs”) in the brain of our little baby. CPCs are sometimes a signal of chromosomal disorders, but Linda did not give us any details. We immediately thought Down’s Syndrome, and spoke our concern, but Linda just said that incidence of any disorder is rare---even with markers. She did note that when CPCs are present, she looks very carefully for other markers. Sally and I noticed that she took a very long look at the heart. While noting that it clearly has four chambers, Linda could not get a good view of blood coming in and going out. Likewise, she couldn’t get a good look at the kid’s nose, the septum of which apparently would have told us something. We didn’t talk to a doctor during this appointment, so we immediately started Googling CPCs on the way home. From the UC, San Francisco website:

The choroid plexus is the part of the brain that makes cerebrospinal fluid, the fluid that normally bathes and protects the brain and spinal column. In about 1 percent to 2 percent of normal babies -- 1 out of 50 to 100 -- a tiny bubble of fluid is pinched off as the choroid plexus forms. This appears as a cyst inside the choroid plexus at the time of ultrasound. A choroid plexus cyst can be likened to a blister and is not considered a brain abnormality.

When they occur, these cysts almost always disappear in normal gestation, and don’t cause any trouble for the baby. The cause for concern, and the reason Linda was taking so many pictures of them, is that CPCs have a loose correlation with a nasty chromosomal disorder called Trisomy 18. If your kid has Trisomy 18, meaning that he or she carries an extra copy of chromosome 18, then the kid is going to have big problems. Likely, the child would be stillborn and almost certainly would not live beyond infancy. While these facts are jolting, the numbers are in our baby’s favor. Trisomy 18 afflicts fewer than one of every hundred children with CPCs. From our amateur internet research, it is not clear that Down’s Syndrome has any correlation with CPCs, even a one-in-a-hundred connection like Trisomy 18.

Sally read a lot more than I did last night. I just wanted to see the numbers and get an idea for the rough odds. Knowing that it’s still a really long shot, I can put it out of my mind until we know more. As we sat there with Linda this afternoon, before I knew about Trisomy 18, I imagined myself as the long-term care provider for a child with Down's Syndrome. I pictured difficult social settings, hard decisions with educators, lamentation about lack of connection, and some fleeting moments of transcendence. With those images in my mind, I pray that I could raise a disabled child without bitterness; that I can be grateful for what has come, regardless of its form.

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