Lymphangioma circumscriptum, a microcystic lymphatic malformation, resembles clusters of small blisters ranging in color from pink to dark red. They are benign and do not require medical treatment, although some patients may choose to have them surgically removed for cosmetic reasons. Cavernous lymphangiomas are generally present at birth, but may appear later in the childs life. These bulging masses occur deep under the skin, typically on the neck, tongue and lips, and vary widely in size, ranging from as small as a centimeter in diameter to several centimeters wide. In some cases, they may affect an entire extremity such as a hand or foot. Although they are usually painless, the patient may feel mild pain when pressure is exerted on the area. They come in the colors white, pink, red, blue, purple, and black; and the pain lessens the lighter the color of the bump. Cystic hygroma shares many commonalities with cavernous lymphangiomas, and some doctors consider them to be too similar to merit separate categories. However, cystic lymphangiomas usually have a softer consistency than cavernous lymphangiomas, and this term is typically the one that is applied to lymphangiomas that develop in fetuses. They usually appear on the neck (75%), arm pit or groin areas. They often look like swollen bulges underneath the skin. Causes
The direct cause of lymphangioma is a blockage of the lymphatic system as a fetus develops, although symptoms may not become visible until after the baby is born. The cause remains unknown.
Usually, lesions are asymptomatic or do not show any evidence of a disease, but, mostly, patients may have random break outs of some bleeding and major drainage of clear fluid from ruptured vesicles.Cavernous lymphangioma first appears during infancy, when a rubbery nodule with no skin changes becomes obvious in the face, trunk, or extremity. These lesions often grow at a rapid pace, similar to that of raised hemangiomas. No family history of prior lymphangiomas is described.Cystic hygroma causes deep subcutaneous cystic swelling, usually in the axilla, base of the neck, or groin, and is typically noticed soon after birth. If the lesions are drained, they will rapidly fill back up with fluid. The lesions will grow and increase to a larger size if they are not completely removed in surgery. Diagnosis
Cases of lymphangioma are diagnosed by histopathologic inspection. In prenatal cases, lymphangioma is diagnosed during the late first trimester or early second trimester using an ultrasound. Other imaging methods such as CT and MRI scans are useful in treatment planning, delineate the size of the lesion, and determine its surrounding vital structures. T2-weight MRI is useful to differentiate lymphangioma from surrounding structures due to its high T2 signal. Classification
Lymphangiomas have traditionally been classified into three subtypes: capillary and cavernous lymphangiomas and cystic hygroma. This classification is based on their microscopic characteristics. A fourth subtype, the hemangiolymphangioma is also recognized. Capillary lymphangiomas
Capillary lymphangiomas are composed of small, capillary-sized lymphatic vessels and are characteristically located in the epidermis.