Only about 1,500 people in the world have been reported to have Erdheim-Chester disease. Twenty-eight-year-old Long Island, New York, attorney Alexa Lofaro is one of them.
Erdheim-Chester disease is one of several diseases known as histiocytic disorders in which white blood cells called histiocytes multiply and spread throughout the body, leading to organ damage. It was previously thought to be an inflammatory disorder. But in 2016, the World Health Organization classified the disease as a form of cancer.
"It's a very slow cancer that is potentially curable. People can live for many decades without treatment," says W. Oliver Tobin, M.B., B.Ch., B.A.O., Ph.D., a Mayo Clinic neurologist. "Because there are multiple mutations that cause this disorder, there are many different ways to treat it."
Before coming to Mayo Clinic in August 2019, Alexa already had been to several neurologists for care. A brain MRI showed she had multiple abnormal areas that were initially suspected to be the result of multiple sclerosis (MS). When Alexa was referred to another local neurologist who specialized in MS, however, she was diagnosed with a different disease called chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids, or CLIPPERS.
This rare inflammatory disease of the central nervous system has symptoms similar to Erdheim-Chester, but it usually improves with steroid medication. Alexa started taking steroids to treat the inflammation. But after six months, her symptoms of double vision, loss of balance and changes in gait continued to worsen.
"By May 2019, I was alternating between somewhat dragging my left leg and swinging it around from the hip," Alexa says. "My speech started changing, as well. It was garbled, and I sounded as though I had marbles in my mouth."
Alexa's mother, who is a nurse, continued to search for answers and for doctors who had expertise in treating her daughter's rare condition, which had begun affecting Alexa's ability to work.
"I couldn't go to court anymore because I was too unsteady to take public transportation," Alexa says. "My mom said we were going to go to Mayo Clinic in Rochester to see Dr. Tobin, who had treated numerous cases of CLIPPERS and could tell us if my diagnosis was correct."
During an appointment on Aug. 13, 2019, Dr. Tobin reviewed Alexa's MRI images. "We had a good idea about what she had the day she got here because she had the brain lesions which are typical of Erdheim-Chester disease," Dr. Tobin says.
Alexa underwent further testing, including bloodwork, a spinal tap, an MRI of the spine and a comprehensive positron emission tomography (PET) scan. Three days later, Dr. Tobin called to say that, based on the PET scan, he believed Alexa had Erdheim-Chester disease.
"A standard PET scan is done from the eyes to the mid-thigh," Dr. Tobin says. "This disease involves the knees and leg. So if you just scanned to the mid-thigh, you would miss that her entire lower leg was abnormal."
After he saw the results of her imaging, Dr. Tobin recommended Alexa undergo a biopsy of the involved areas of bone in her lower leg. That test would be overseen by a group of specialists familiar with the rare cancer Dr. Tobin suspected in Alexa.
"We have a multidisciplinary Histiocytosis Working Group, coordinated by hematologist Ronald Go, M.D. We meet once a month and are in regular communication when we have a patient like Alexa," Dr. Tobin says. "There's a particular way a bone biopsy has to be performed when histiocytosis is suspected. Our histiocytosis radiologist, Jason Young, M.D., coordinated a high-tissue volume bone biopsy based on the PET scan results. Histiocytosis pathologist Karen Rech, M.D., directed how to correctly handle the bone biopsy to ensure that we not only reached a diagnosis, but could identify the appropriate treatment."
The bone biopsy confirmed Alexa had Erdheim-Chester. Then genetic testing on the biopsied tissue revealed the mutation that was causing Alexa's disease. "Treatment depends on the genetic mutation of the tissue," Dr. Tobin says. "The genetic testing we did allowed her treating neurooncologist in New York to identify which treatment she would best respond to."
"My doctor speaks with Dr. Tobin and discusses how I'm responding to the treatments. It feels comforting to have the team that diagnosed me also in the wings."Alexa Lofaro
In September 2019, Alexa began a targeted therapy that's used to treat melanoma. It's an oral medication she takes daily for 21 days. Then she takes a week off and begins another cycle. Alexa currently is on her fourth treatment cycle.
"My doctor speaks with Dr. Tobin and discusses how I'm responding to the treatments," Alexa says. "It feels comforting to have the team that diagnosed me also in the wings. Without that diagnosis, I wouldn't have a treatment to respond to."
Alexa's diagnosis was truly a group effort, according to Dr. Tobin. "She couldn't have had this diagnosis within a week if not for our multidisciplinary Histiocytosis Working Group comprised of hematologists, radiologists, pathologists and multiple other specialties," he says. "The combination of this multidisciplinary group and the research infrastructure provided by both the Center for Multiple Sclerosis and Autoimmune Neurology and the Lymphoma SPORE (Specialized Programs of Research Excellence) are critical for the accurate diagnosis of patients like Alexa, and for developing new cures for this and similar disorders."
Since beginning the medication, and with help from a physical therapist, Alexa is able to speak more clearly, and her balance and gait are improving. An MRI and PET scan in November 2019 showed the lesions in her brain and leg have shrunk.
"I'm able to stand more comfortably now," she says. "Before the treatment, I had gotten to the point where I could not walk without holding on to someone for support and using a cane at the same time. Now I am able to walk in my home without use a cane."
As her treatment has moved forward, Dr. Tobin has reached out to Alexa on several occasions to check her progress. "It shows that he cares and is looking out for my interest," Alexa says. "Mayo is what medicine should be. It's the height of medicine."