Fine-Needle Aspiration of Cysts

I’ve had fibrocystic breast for about 15 years. During that time I’ve had an annual mammogram and physical examination by an experienced surgeon. We’ve been following a cyst in my left breast for about the past six or eight years. Over the last year I’d found during regular breast self-examination (BSE) that the cyst had become larger and more painful. When I mentioned this to my surgeon, she compared the new mammogram with the one from the previous year.

I wasn’t surprised when the doctor confirmed that the cyst was indeed larger than it had been the year before. But I was surprised when she said, “And there’s one about the same size in the right breast as well.” I hadn’t felt the new cyst during BSE. Since the new cyst was much closer to the surface than the old one, I was surprised that I hadn’t felt it and that it wasn’t sore to the touch, while the deeper one was.

When my surgeon (I’ll call her Dr. Harper) suggested that she drain both cysts, I agreed without hesitation. She then began the process technically known as ultrasound-guided fine-needle aspiration.

Ultrasonography (ultrasound) uses high-frequency sound waves to produce images of the inside of the body. Different kinds of tissue absorb or reflect (echo) the sound waves in varying degrees. The person administering the ultrasound first covers the area of the body under examination with a lubricant, then moves a wand-like device over the area. The device both emits sound waves and receives their echoes as it touches the skin. Solid tissue inside the body reflects the waves back, producing a picture in white and various shades of gray on the screen. But because a cyst is filled with fluid, the sound waves pass right through it; the lack of reflected waves makes the cyst show up on the screen as a dark ovoid area, something like a black hole.

To drain the cysts Dr. Harper first localized the cyst on the screen, then inserted a very thin (fine) needle through the tissue until the needle punctured the wall of the cyst. She then extracted the fluid into the syringe. As the fluid was extracted, the black hole on the screen quickly shrank and then disappeared. Because the needle is thin, the procedure doesn’t hurt (well, not too much). It was more painful on the cyst in the left breast because that one was deeper within the tissue.

The fluid in one syringe was cloudy white, while that in the other syringe was cloudy but darker. The brown tinge to the fluid in the second syringe was probably caused by the presence of dried blood cells. Dr. Harper sent both specimens off to the lab for analysis. She said, though, that she didn’t expect the analysis to indicate any problems. “There’s usually only cause for concern when the cyst doesn’t drain completely,” she said. She called me the next day to say that all the material found in the fluid from both cysts was benign (non-cancerous).

Cysts like mine are harmless, but they can be painful. Draining them eliminates that pain. Another reason to drain cysts is that large ones might mask the appearance on a mammogram of a tumor in the tissue behind the cyst.