Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Dr. Lee was born in Shanghai, China, and received his college and medical training in the United States. He is fluent in English and three Chinese dialects. He graduated with chemistry departmental honors from Harvey Mudd College. He was appointed president of AOA society at UCLA School of Medicine. He underwent internal medicine residency and gastroenterology fellowship training at Cedars Sinai Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Medical Author: Melissa Conrad Stöppler, MD
Medical Editor:
William C. Shiel Jr., MD, FACP, FACR
A cyst is a closed sac- or bladder-like structure that is
not a normal part of the tissue where it is found. Cysts are common and can
occur anywhere in the body in persons of any age. Cysts usually contain a
gaseous, liquid, or semisolid substance. Cysts vary in size; they may be
detectable only under a microscope or they can grow so large that they displace
normal organs and tissues. The outer wall of a cyst is called the capsule.
Cysts can arise through a variety of processes in the body, including...
A Baker cyst is swelling caused by fluid from the knee joint protruding to the back of the knee.
Baker cysts are not uncommon and can be caused by virtually any cause of joint swelling (arthritis).
A Baker cyst may cause no symptoms or be associated with knee pain and/or tightness behind the knee, especially when the knee is extended or fully flexed.
Baker cysts can rupture and become complicated by protrusion of fluid down the leg between the muscles of the calf (dissection).
Baker cysts can be treated with medications, joint aspiration and cortisone injection, and surgical operation, usually arthroscopic surgery.
What is a Baker cyst?
A Baker cyst is swelling caused by fluid from the knee joint protruding to the back of the knee. The back of the knee is also referred to as the popliteal area of the knee. A Baker cyst is sometimes called a popliteal cyst. When an excess of knee joint fluid is compressed by the body weight between the bones of the knee joint, it can become trapped and separate from the joint to form the fluid-filled sac of a Baker cyst. The name of the cyst is in memory of the physician who originally described the condition, the British surgeon William Morrant Baker (1839-1896).
What causes a Baker cyst?
Baker cysts are not uncommon and
can be caused by virtually any cause of joint swelling (arthritis). The excess joint fluid (synovial fluid) bulges to the back of the knee to form the Baker cyst. The most common type of arthritis associated with Baker cysts is osteoarthritis, also called degenerative arthritis. Baker cysts can occur in children with juvenile arthritis of the knee. Baker cysts also can
result from cartilage tears (such as a torn meniscus),
rheumatoid arthritis, and other knee problems.
What are symptoms of a Baker cyst?
A Baker cyst may cause no symptoms or be associated with
knee pain and/or tightness behind the knee, especially when
the knee is extended or fully flexed. Baker cysts are
usually visible as a bulge behind the knee that is
particularly noticeable on standing and when compared to the
opposite uninvolved knee. They are generally soft and
minimally tender.
Baker cysts can become complicated by protrusion of
fluid down the leg between the muscles of the calf (dissection). The cyst can rupture, leaking fluid down the inner leg to sometimes cause the appearance of a painless bruise on the inner ankle. Baker cyst dissection and rupture are frequently associated with swelling of the leg and can mimic phlebitis of the leg. A ruptured Baker cyst typically causes rapid-onset swelling of the leg.
How is a Baker cyst diagnosed?
Baker cysts can be diagnosed by the doctor's
examination and confirmed by radiological testing (either
ultrasound, injection of contrast dye into the knee
followed by imaging, called an arthrogram,
or MRI scan) if necessary.
How is a Baker cyst treated?
Baker cysts often resolve with aspiration (removal) of excess knee
fluid in conjunction with cortisone injection. Medications
are sometimes given to relieve pain and inflammation.
When cartilage tears or other internal knee problems are
associated, surgery can be the best treatment option. During a surgical
operation, the surgeon can remove the swollen tissue
(synovium) that leads to the cyst formation. This is most commonly done with arthroscopic surgery.
REFERENCES:
Klippel, John H., et al., eds. Primer on the Rheumatic Diseases. 13th ed. New York: Springer and Arthritis Foundation, 2008.
Ruddy, Shaun, et al., eds. Kelley's Textbook of Rheumatology. Philadelphia: W.B. Saunders Co., 2000.
Additional resources from WebMD Boots UK on
Baker's Cyst
Rheumatoid arthritis is an autoimmune disease that causes chronic inflammation of the joints, the tissue around the joints, as well as other organs in the body. Because it can affect multiple other organs of the body, rheumatoid arthritis is referred to as a systemic illness and is sometimes called rheumatoid disease.
The knee joint is composed of three compartments and ligaments which stabilize the joint. Causes of knee pain may include injury, degeneration, infrequently infection and rarely bone tumors. Although routine x-rays do not revel meniscus tears, they can be used to exclude other problems of the bones and tissues. The knee joint is the most commonly involved joint in rheumatic disease, as well as immune diseases that affect various tissues of the body.
Osteoarthritis is a type of arthritis caused by inflammation, breakdown, and eventual loss of
cartilage in the joints. Also known as degenerative arthritis. Osteoarthritis
can be caused by aging, heredity, and injury from trauma or disease.
Cysts are saclike structures that can occur throughout the body and usually contain a semisolid, liquid, or gaseous substance. Infections, tumors, genetic conditions, chronic inflammatory conditions, and wear and tear can cause cysts. Though some cysts may be palpable, others may not produce any symptoms. Treatment depends upon the location and cause of the cyst.
A ganglion is a fluid-filled cyst that forms from the joint or tendon lining. Ganglia are most frequently found in the ankles and wrists and are usually painless. A ganglion often resolves on its own. Aspiration of the ganglion fluid or surgery may be necessary.
Osteoarthritis is a joint inflammation that results
from cartilage degeneration.
Osteoarthritis can be caused by aging, heredity, and
injury from trauma or disease.
The most common symptom of osteoarthritis is pain in
the affected joint(s) after repetitive use.
There is no blood test for the diagnosis of
osteoarthritis.
The goal of treatment in osteoarthritis is to reduce joint
pain and inflammation while improving and maintaining joint function.
What is osteoarthritis?
Osteoarthritis is a form of arthritis that features the breakdown and eventual loss of the cartilage of one or more joints. Cartilage is a protein substance that serves as a "cushion" between the bones of the joints. Among the over 100 different types of arthritis conditions, osteoarthritis is the most common, affecting over 25 million people in the United Stat...
