Lymphatic malformations (LM)
The most common abnormality of lymphatics is lymphatic hypoplasia (reduced or absent lymphatics) which may present as lymphoedema. This is a form of oedema (swelling) caused by collection of lymphatic fluid in the tissue.Lymphoedema may be obvious at birth or be noticed for the first time in childhood.
The second type is the cystic lymphatic malformation which can be made up of large (macro) cysts or small (micro) cysts or both large and small cysts. This type can be near the surface resulting in fluid filled blebs or warty lesions on the skin or can be deeper hence presenting as a swelling beneath normal looking skin. Although cystic lymphaticmalformations are always present at birth they may not be noticed until a complication occurs such as a bleed, an infection or a leakage of lymph which results in sudden swelling and pain. If the unknown cystic lymphatic malformation is near the airway or near the eye, this swelling can be critical.
Lots of other now outdated terms have been used in the past to describe cystic lymphatic malformations. These include lymphangioma, lymphangioma circumscriptum, lymphangioma simplex, verrucous haemangioma and angiokeratoma circumscriptum for microcystic lymphatic malformations. Macrocystic lymphatic malformations have been called cystic hygromas and cavernous lymphangiomas.
Sometimes microcystic or macrocystic lymphatic malformations occur in association with other vascularmalformations. The combinations include capillary-lymphatic malformations (red or pink colour), venous-lymphatic malformations (blue colour under the skin) , capillary-venous-lymphatic malformations and arteriovenous-lymphatic malfromations.
The visible, surface part of the lymphatic malformation is usually not a good indication of the full extent of the problem. Magnetic resonance imaging (MRI) is an accurate method for assessing the extent of the macrocystic component. Ultrasound is also useful in the diagnosis and assessment of lymphatic malformations. Doppler flow studies help with assessment of any associated capillary, venous or arteriovenous components.
Treatment often requires a multi-disciplinary team of vascular malformation specialists including dermatologists, interventional radiologists and surgeons. It is crucial to have the right diagnosis and to assess the extent of the malformation prior to planning treatment.
Treatment of lymphatic malformations depends on the size and location of the lesion. Treatment involves gaining access to the lesion under ultrasound or fluoroscopic guidance, draining the cysts and injecting a sclerosants. The choice of sclerosant depends on the size of the lesion. Agents used include doxycycline , sodium tetradecyl sulphate, bleomycin and OK 432. In Australia, OK 432 is not a registered drug and we tend to use the other agents more commonly. Most patients require 3 to 4 sclerotherapy treatments. Once a lesion has been reasonably treated with sclerotherapy, in some patients, the residual cyst is removed surgically.
Vascular Malformation Investigations
