Pediatric Lymphatic Malformation

  • Etiology: Obstruction of developing lymphatic system resulting in multiple unencapsulated cystic lymphatic spaces lined by epithelial cells separated by minimal stroma
  • Imaging:
    — May be multicentric
    — Cross tissue planes and have transpatial extension
    — Mediastinal extension with airway compression
    — Macrocystic (mean diameter of cystic lesions greater than 1 centimeter) or microcystic (mean diameter of cystic lesions less than 1 centimeter) or mixed
    — In microcystic form individual cysts may not be perceptible
    — Cysts may be heterogeneous depending on their protein or hemorrhage content
    — Hemorrhage into cysts forms fluid-fluid levels
    — Thickened septa contains venous component which may enhance
  • Imaging US:
    — Have lace-like appearance
    — Contents usually anechoic but may contain debris, high-lipid content, infection, and blood
    — Imaging US Color Doppler: Arterial and venous flow in septa
  • Imaging CT: Usually homogenous and cystic
  • Imaging MRI:
    — T1WI: Variable signal intensity depending on protein content and hemorrhage
    — T1WI post contrast: Septal enhancement
    — T2WI: High signal intensity with fluid-fluid levels from hemorrhage
  • DDX:
  • Complications: Subject to hemorrhage and or infection in cyst walls
  • Treatment:
  • Clinical:
    — Presents at birth and grows with patient
    — Often presents with acute swelling from post traumatic hemorrhage or spontaneous hemorrhage or infection in venolymphatic malformation so in setting of large hematoma out of proportion to mild trauma look for underlying venolymphatic malformation
    — Often in posterior cervical space
    — 75% on head or neck or torso, 25% in axilla
    — Can also be in orbit
    — If seen prenatally consider delivery via an EX utero Intrapartum Treatment (EXIT) procedure

Radiology Cases of Lymphatic Malformation

MRI of lymphatic malformation
Transverse (above) and sagittal (below) US of the neck and coronal (above) and axial T2 MRI without contrast of the neck shows an infiltrating multicystic mass of the neck surrounding the trachea that has minimal vascularity.
MRI of lymphatic malformation of orbit
Coronal T1 MRI without contrast (left) shows a round low signal intensity left medial canthus lesion that is high signal intensity on T2 (middle) and that does not enhance with contrast (right).
MRI of lymphatic malformation of the chest wall
Axial T1 without contrast (top), T2 (middle) and T1 with contrast (bottom) MRI of the chest shows a mass composed of multiple large fluid-filled structures separated by thin septations which faintly enhance.
CXR and CT of lymphatic malformation of the thymus
CXR AP obtained intially (left) shows a normal appearing exam with a normal appearing thymus. CXR AP obtained 10 days later for continued respiratory distress (right) showed interval development of an anterior mediastinal mass. Axial+coronal CT with contrast of the chest shows a large low density anterior mediastinal mass with multiple thin septations.

Clinical Cases of Lymphatic Malformation

Clinical image of lymphatic malformation
Clinical images (above) show a large bilateral neck and facial mass which was demonstrated by transillumination (below) to be cystic.

Histopathology Cases of Lymphatic Malformation

Histopathology image of lymphatic malformation
Histopathological image H&E stained section shows irregular, fibrous walled vascular channels lined by a single layer of endothelial cells. The channels are empty or contain serous fluid. Scattered lymphocytes are present, as are few bundles of smooth muscle cells.