Kaposiform lymphangiomatosis (KLA) is a rare condition that affects the lymphatic system. In KLA, the lymphatic system vessels expand and can spread and cause damage to tissues, bones, and organs. The condition can worsen over time.

Children often present with respiratory symptoms, such as shortness of breath, because fluid from the lymphatic vessels may leak into the chest area. This buildup of fluid can be dangerous to organs in the body.

KLA may also affect blood clots, which may lead to some life threatening consequences. Only a few options exist to treat the condition. People may wish to work with a doctor with expertise in this disease to discuss suitable diagnostic and treatment processes.

Keep reading to learn more about kaposiform lymphangiomatosis.

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KLA affects the lymphatic system, which is part of the immune system. It helps the body fight off foreign substances and infections. Like blood vessels, the lymphatic vessels also supply the entire body.

While KLA can affect every organ, it mainly affects the lungs and chest. Symptoms of KLA typically start during childhood. Babies and children may experience shortness of breath and a persistent cough. These symptoms occur because of fluid building up in the chest, particularly around the lungs and heart.

Other symptoms people may experience with KLA include:

  • pain
  • atypical bleeding
  • mild and severe bruising
  • soft growths under the skin

In a 2019 study, experts reported that the average age that symptoms start is just over 2 years old. Other characteristics of KLA include thrombocytopenia and coagulopathy.

Thrombocytopenia occurs when a person has a low number of blood-clotting cells called platelets. With a low level of platelets, people may have issues stopping a bleed. This can also lead to atypical bleeding and bruising relating to KLA. Doctors refer to atypical bleeding as coagulopathy.

Experts are unsure about the exact cause of KLA, but it is likely not an inherited disease. That said, a 2019 study suggests that KLA occurs due to a mutation in genes responsible for lymphatic vessel development.

The researchers analyzed biopsy samples from the tumors of people with KLA. They found that a gene mutation affecting the RAS pathway may cause the disease.

The RAS pathway is important in cell signaling, and mutations may alter its function. Health researchers have also identified mutations in RAS pathways in many cancer types.

Doctors can diagnose KLA by first taking a medical history, allowing them to gather information about a person’s symptoms.

Some tests to help the diagnostic process include:

  • physical exams
  • laboratory tests, such as blood tests and genetic tests
  • imaging tests
  • a biopsy, particularly if the bone is involved

When doctors notice bruising on the skin, or petechiae, it may lead them to suspect that someone may have a blood clotting issue. Petechiae refers to small red spots on the skin due to blood leaking from the blood vessels.

Blood tests

Diagnosing a blood clotting problem may include blood tests.

A complete blood count (CBC) can reveal important information about different blood cells in the body, including whether the amount of platelets in the blood is within typical ranges. Also, elevations in specific proteins in the blood, such as elevated angiopoietin-2 and D-dimer, can indicate KLA.

Blood tests may also reveal hypofibrinogenemia, a key feature of KLA. Hypofibrinogenemia refers to low levels of fibrinogen, a protein involved in blood clotting.

Another test called a blood smear can reveal any structural abnormalities in the shape or size of the cells using a microscope.

Imaging tests

A CT and MRI of the chest can be beneficial in diagnosing KLA. Imaging can show where lesions and tumors are in the lungs, chest, or bone. They may also reveal where fluid buildup occurs.

Treatments for KLA often may not yield a cure. Research on treatment for the condition is limited, as it is an extremely rare disease. Studies also show inconsistent results from KLA treatments. For example, a 2019 study found that no single drug or combination of drugs provided similar responses among the six participants.

The goals when trying to treat KLA include the following:

  • reducing the size of lesions or tumors in the lymphatic vessels
  • improving symptoms
  • restoring blood clotting

Some procedures that doctors may use to help manage KLA symptoms include:

  • thoracotomy — removing atypical tissues in the chest through surgery
  • thoracoscopy — removing atypical tissues in the chest through a tube-like instrument
  • draining fluid from the chest with a chest tube
  • pericardiocentesis — removing fluid buildup in the tissue lining the heart
  • splenectomy — removing the spleen

Surgery is complicated for people with KLA because lesions and tumors can be widespread in the body. Additionally, blood clotting problems can increase the risk of complications.

In severe situations or for people who do not respond to these treatments, doctors may recommend a plasma or platelet infusion. These procedures can help manage blood clotting.

Some researchers suggest that RAS pathway blockers may have a potential role in KLA treatment. However, more research into their effectiveness for KLA is necessary.


A small 2021 study explored the effectiveness of sirolimus on KLA. Sirolimus is an immunosuppressant that works on the immune system to dampen its effect. While more research is necessary to confirm the effectiveness of this medication, it may provide a partial improvement in symptoms. Also, children who received sirolimus in this study did not have serious side effects.

When there is bone involvement, doctors may choose to combine sirolimus with bisphosphonates.

Medications to help ease symptoms

Doctors can help people living with KLA feel more comfortable by treating their specific symptoms. Some treatment options for the condition include chemotherapy and steroids. Chemotherapy can help make tumors in the lymphatic vessels smaller.

Steroids, such as prednisone, can treat coagulopathy relating to KLA.

KLA is a severe condition with significant effects on health. For some, the condition can be life threatening. Additionally, there are no standard treatments available for KLA.

Unfortunately, KLA has a negative outlook. The likelihood of the disease being fatal is high due to the risk of complications of the following conditions:

  • thrombocytopenia
  • coagulopathy
  • pleural effusion, or a buildup of fluid between tissues that line the lungs and the chest
  • pericardial effusion, or a buildup of fluid in the space around the heart

What is the life expectancy of someone with KLA?

A 2021 study reports that the overall survival rate for KLA is approximately 34%. This is the percentage of people who survive a disease following a certain time after diagnosis. Even with aggressive attempts to treat KLA, the survival rate 5 years after diagnosis is 51%.

Kaposiform lymphangiomatosis (KLA) is a rare disease that usually causes symptoms during childhood. People usually have fluid buildup and tumors or lesions in the chest or lungs. However, KLA can affect the entire body. The outlook for the condition tends to be unfavorable because it negatively affects blood clotting.

Few treatments are available to help manage the symptoms, so more research is necessary to improve our understanding of the disease and develop effective treatments.