What are the other Names for this Condition? (Also known as/Synonyms)

• JAM (Juxta-Articular Myxoma)
• Juxtaarticular Myxoma

What is Juxta-Articular Myxoma? (Definition/Background Information)

• Juxta-Articular Myxoma (JAM) is an infrequent, benign tumor of the soft tissues, regularly occurring near large joints in the fat tissues below the skin
• They are primarily composed of primitive connective tissues (tendons); and are closely linked to changes in ganglion cysts, which are a group of synovial fluid-filled sacs
• Young adults and middle-aged individuals are most prone to this disorder. The painful lesions appear as small lumps near joints and tendons
• The most frequent location of this tumor is the knee joint, followed by joints of the elbow, shoulder, ankle, and hip region
• Juxta-Articular Myxoma may be removed through surgery and the prognosis is good with suitable treatment. However, the tumor may recur after treatment

Who gets Juxta-Articular Myxoma? (Age and Sex Distribution)

• Juxta-Articular Myxoma is mostly observed in the young to mid-adult phase of an individual (20-50 years old; average age 43 years)
• However, it may be present in a much wider age group - from young children to the very old
• There is a slight predisposition towards the male gender; male-female ratio is nearly 3:1
• There is no known ethnic or racial preference

What are the Risk Factors for Juxta-Articular Myxoma? (Predisposing Factors)

The following factors may increase the risk for Juxta-Articular Myxoma formation:

• External injury or trauma to a joint
• Osteoarthritis

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Juxta-Articular Myxoma? (Etiology)

• The exact cause and mechanism of Juxta-Articular Myxoma formation is unknown. They are thought to occur as a reactive process, due to some preexisting condition
• These preexisting conditions may include:
  • Any physical injury, either to the knee or any joint
  • Osteoarthritis (age-related joint wear and tear)

What are the Signs and Symptoms of Juxta-Articular Myxoma?

The presentations are based on the location of the tumor. Juxta-Articular Myxoma signs and symptoms include:

• In the initial growing phase of the tumor, it may be asymptomatic
• The benign nodules may grow at a very slow rate and appear as well-defined inflammations with tenderness and pain
• They may also cause reduced motion range and discomfort in the affected joint/area
• JAM mainly occurs in the knees - in almost 90% of the cases. Other long bone joint locations may include the shoulder, hip, elbow, and ankle regions

How is Juxta-Articular Myxoma Diagnosed?

A diagnosis of Juxta-Articular Myxoma may be made using the following tools:

• Complete physical examination and thorough evaluation of patient’s medical history
• X-ray studies of the tumor at the joints
• MRI scan of the affected region
• Tissue biopsy: A tissue biopsy is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Juxta-Articular Myxoma?

The possible complications of Juxta-Articular Myxoma include:

• Severe pain, which may be complicated further by the presence of co-existing osteoarthritis (if any)
• The mobility of the joints can be constrained and lead to mobility issues such as while walking and performing normal daily activities, thereby affecting one's overall quality of life
• Damage of the knee, hip, elbow, or other organs, vital nerves, and blood vessels, during surgery to remove the tumor
• Recurrence of JAM after surgery; the recurrence rate is noted to be high

How is Juxta-Articular Myxoma Treated?

Treatment measures for Juxta-Articular Myxoma include the following:

• If there are no symptoms, then conservative measures may be adopted and periodic observations maintained
• Arthroscopic surgery to remove the tumor, when it is well-defined and localized
• Open surgery is performed when the lesion is diffuse (spread into the region). A complete excision enhances the possibility of non-recurrence
• Post-operative care is important until the surgical wound heals
• Follow-up care with regular screening and check-ups are important, since the tumor can recur in some cases

How can Juxta-Articular Myxoma be Prevented?

• Current medical research has not established a method of preventing Juxta-Articular Myxoma
• It may help to keep the risk factors low by treating osteoarthritis, before it starts to decrease the quality of life, and by avoiding physical activities that might put intense pressure on the joints
• Regular medical screening at periodic intervals with blood tests, scans, and physical examinations are mandatory for those who have already endured the tumor; due to both its metastasizing potential and chances of recurrence. Often several years of active vigilance is necessary

What is the Prognosis of Juxta-Articular Myxoma? (Outcomes/Resolutions)

• The prognosis is excellent when small lesions are located just below the skin surface. Their recurrence risk can also be completely avoided
• Surgical excision of Juxta-Articular Myxoma is difficult and complex, if it has generally spread around the joint
• The recurrence rate is moderate to high at 34% on surgical removal of the tumor. Hence, regular follow-up with medical screening is required

Additional and Relevant Useful Information for Juxta-Articular Myxoma:

A myxoma is a benign tumor of the connective tissues. The most common myxoma variant (there are about seven types) is the atrial myxoma. Among all the types of heart tumor, atrial myxoma is the most frequently occurring heart tumor in adults.