Imaging
The following imaging is used to diagnose isolated lymphatic malformations (LMs):
- Ultrasound can help distinguish fluid-filled LM cysts from solid masses. LMs can sometimes be seen even before birth on a prenatal ultrasound.
- Magnetic Resonance Imaging (MRI) offers significantly more detail than ultrasound. It can measure the size of the LM, identify macro- and micro-cysts, and how the LM impacts nearby structures like organs, muscles, or nerves.
Genetic Testing
Genetic testing is not required to diagnosis an isolated LMs. However, genetic testing may be recommended in certain situations — such as when the diagnosis is unclear; symptoms are unusual or severe, or when results may help guide treatment decisions. Your care team can help determine whether genetic testing may be useful. It’s important to note that:
Most Isolated Lymphatic Malformations (LMs) are caused by variants in the PIK3CA gene, so testing is not always performed unless results change care.
LM are caused by somatic gene mutations that are not typically found in blood, so testing is done on tissue from the affected area. Because these mutations are not present in every cell, genetic testing can sometimes have a negative result.
Emerging research is exploring the use of cell-free DNA from fluid samples, but this approach is not widely available to all patients.
Genetic testing may be required to determine eligibility for certain clinical trials or access to investigational therapies through expanded access or compassionate use programs.
