Kaposiform lymphangiomatosis

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Kaposiform lymphangiomatosis (KLA) is a rare lymphatic anomaly associated with a poor prognosis. Disease hallmarks include multifocal, intra- and extra-thoracic lymphatic malformations, thrombocytopenia and consumptive coagulopathy.

Epidemiology

The exact prevalence and incidence of kaposiform lymphangiomatosis is unknown, but the disease is very rare. The disease usually presents at birth or early childhood, however reports exist of disease manifestations later in life . Males and females appear equally affected. The exact cause is unknown however genetic factors and changes in utero are thought to contribute to disease development.

Clinical presentation

Due to the generalized and multi-system involvement of the disease, clinical presentation can vary making diagnosis difficult. However, the most common presenting features include:

  • respiratory symptoms (dyspnea, cough)
  • bleeding/hemorrhage - often secondary to coagulopathy
  • pericardial and pleural effusions (often hemorrhagic)
  • fractures secondary to bone involvement
  • discrete tissue swelling/mass

The disease often involves both intra- and extra-thoracic structures of the chest and abdomen.

Pathology

Kaposiform lymphagiomatosis arises due to a malformation of the lymphatic system. It is characterized by multi-organ involvement and nearly all patients have intra-thoracic involvement. Most common organs involved are the lung, heart, bone, and spleen.

Microscopic appearance

Histopathology generally shows malformed dilated lymphatic channels associated with clusters or sheets of spindle-like cells. There is no atypia or dysplasia. Immunochemical staining is positive for markers of lymphatic endothelium.

Radiographic features

Imaging varies depending organ systems affected but is useful to aid in diagnosis.

Plain radiograph

Plain radiographs are of limited use as they often show nonspecific changes but may demonstrate changes in keeping with lung disease on chest radiographs (e.g. pleural effusions). Plain radiographs may be useful in bone imaging showing lytic lesions with cortical sparing, asymmetrically involving the axial and/or appendicular skeleton .

CT

CT imaging of the chest may demonstrate:

  • infiltrative, enhancing soft tissue thickening along bronchovascular bundles (following lymphatic distribution)
  • mass of low attenuation

CT imaging of the abdomen may demonstrate:

  • organomegaly, especially splenomegaly, hepatomegaly or nephromegaly
  • hypodense cystic lesions involving the spleen, kidneys, and pancreas
  • retroperitoneal involvement is common and may demonstrate an enhancing, infiltrative soft tissue mass, commonly with extension to other structures including the mesentery, hepatic or renal hila, or along vessels in these reigons
MRI

MRI imaging of the chest may demonstrate:

  • mass or soft tissue thickening as on CT that is heterogeneous and hyperintense on fluid-weighted sequences, with moderate to intense post contrast enhancement

MRI imaging of the abdomen may demonstrate:

  • cystic lesions that are heterogeneous and hyperintense on fluid-weighted sequences

Treatment and prognosis

There is no current consensus on treatment, but patients are treated with a combination of medical and surgical therapies. Medical therapies may include combinations of steroids, chemotherapy and immunomodulators (inferferon, siolimus, vincristine) but responses are unpredictable. Surgical procedures are usually for symptomatic benefit however splenectomy appears beneficial in some patients for refractory thrombocytopenia.

Prognosis is generally poor as the disease is progressive despite medical intervention.

Differential diagnosis