Lymphangiomas are benign abnormal collections of lymphatic vessels forming a mass composed of cystic spaces of variable size, which have the potential for local extension, thereby infiltrating surrounding structures. Lymphangiomas, cystic hygromas, and lymphangiomatosis can affect almost any area of the body where lymphatics are present, but predominate in the head, neck and axilla. Constituting 5.6% of all benign lesions of infancy and childhood, lymphangiomas have no predilection for sex or race. Lymphangiomas can also occur in the lung, gastrointestinal tract, spleen, liver and bone, and may be a manifestation of multifocal disease if found in these last three organs. Abdominal lymphangiomas are rare.

Lymphangiomas should not be confused with primary lymphedema, a disorder in children and adolescents causing swelling in an extremity. This condition is associated with several genetic syndromes and in contrast to lymphangiomas has the potential for malignant transformation with time.

Gross observed that 65% of lymphangiomas were apparent at birth, and that 90% appeared by the end of the second year of life. The principal mode of presentation is that of a disfiguring, usually slow growing mass. Rapid enlargement, sometimes overnight, may occur following systemic infection or bleeding into the tumor.

Etiology and pathogenesis

The etiology of lymphangiomatous malformations is believed to be a developmental defect in lymphatic pathways which develop from the sixth week of gestation onwards, resulting in obstructed or inadequate efferent channels and proximal dilatation of afferent channels. The lymphatic system develops from five primitive sacs originating from the venous system.