This wasn’t turning out to be a cut-and-dried case after all. A hugely swollen leg in an elderly woman with a history of cancer had seemed so likely to be a blood clot, but two ultrasounds and a CT scan later, we had found nothing.
Mrs. Schulman was convinced that her knee was the problem. After her fall, she told us, her knee had been swollen for a week or so. It improved, although it still ached if she walked a lot. The massive leg swelling started more than a month later. But when I called the doctor who had seen her, he thought it unlikely that a fall could have caused this extreme degree of swelling.
Mrs. Schulman asked if an antibiotic might help. I explained to her that there was no sign of infection. Her white blood cell count, which would increase in an infection, was completely normal, and the leg did not have the increased warmth or redness that might suggest an infection of the skin or soft tissues. Instead, I suggested trying a diuretic, a medicine that helps reduce the amount of water in the body, for a week. In some cases swollen legs are simply due to water retention from poorly functioning veins. I didn’t think there was much chance that was the case here, since both legs would most likely be swollen. Still, a diuretic probably wouldn’t hurt.
We sent her home, but not without some trepidation. We warned her about symptoms of a blood clot in the leg, such as redness, warmth, or tenderness, or—in a worst-case scenario—the chest pain, rapid heart beat, or shortness of breath that would result from a pulmonary embolus. Later that afternoon, still worried, I spoke with a radiologist who recommended an MRI of her leg and pelvis. Perhaps there was something obstructing the veins that hadn’t been visible on either the ultrasound or the CT scan. Anything that blocks or diminishes blood flow—a blood clot within the vein, a mass pressing on the outside of the vein, damage to the vein itself—can build up pressure that is transmitted to the capillaries, causing swelling.
I called Mrs. Schulman and apologized that I was recommending yet another test, the MRI. I explained that there was a good chance that this one would give us an answer. She was eager to do whatever it took. A week later, we had the results: no blockages visible in the blood vessels and no compression of the veins.
Desperate to find the problem, caught up in a cascade of testing, frustrated that after more than a month her leg remained worryingly swollen, I persuaded myself to keep looking for a hidden blood clot. So I ordered a venogram, in which a
contrast dye is injected into a vein and a series of X-rays depicts the flow of the dye—or, if there’s an obstruction, a lack of flow. Although it is the gold standard for diagnosing deep vein thrombosis, a venogram comes with the risk of serious allergic reaction to the dye. I also consulted an oncologist, who sent Mrs. Schulman for another CT scan as well as a positron emission tomography (PET) scan, which uses small amounts of radioactive substances to generate three-dimensional images of metabolic processes within tissue and organs. Three tests and one consultant later, we had found no blood clot and no cancer but were no closer to an answer for her swollen leg.
Mrs. Schulman made the best of life with a huge, stiff leg. She lifted it carefully when climbing stairs, and she didn’t plant a garden that spring. In the summer, she visited her family out of town for a few weeks. Still very worried about a blood clot, I left a series of messages for her, asking her to call when she returned. When I didn’t hear back, I wondered if a clot had barreled through her veins to her lungs, and if she had ended up hospitalized or dead. Or maybe she had gone to another doctor who had solved the mystery, and she had decided never to see me (or Charles) again.
About a month later, she finally picked up the phone. “It’s better,” she said, cheerful as ever.
My heart lifted. “You mean, the swelling is down a little?”
“No, it’s back to normal. Same size as the other one.”
My mouth dropped open. Mrs. Schulman told me she’d taken an antibiotic prescribed by her other doctor for the knee pain, and within a week, the swelling had melted away.
I called her doctor, eager to hear the story. He’d thrown up his hands, he told me. So many tests, no answers, and a patient who had wanted an antibiotic from day one. It made no sense, he said, but why the heck not.
Though it was possible she had an infection whose signs we missed and that the antibiotic cleared up, my take was that it was a coincidence. Some antibiotics have anti-inflammatory effects on arthritis when used over time, but I didn’t think arthritis was the underlying cause of her leg swelling either.
Even though Mrs. Schulman recovered in the aftermath of antibiotic treatment, I wasn’t convinced it made a difference. Whatever made the swelling subside was as mysterious as whatever had caused it.
In up to a quarter of the cases of single-leg swelling with negative venograms, no precise cause is ever identified. Plenty of questions
cannot be answered by
diagnostic tests, and often, symptoms fade before we can pinpoint their exact cause. Time may not heal all wounds, but as far as I am concerned, it worked for this one.
is an internist in West Haven,
Connecticut. The cases described
in Vital Signs
are real, but names and certain
details have been changed.