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Lymphatic malformation (LM), formerly referred to as lymphangioma, is a malformation localised to the lymphatic system. Prevalence is unknown. There are two types of LM: macrocystic LM (hygroma cysticum or cystic lymphangioma) and tissue-infiltrating microcystic LM (lymphangioma circumscriptum) that leads to the formation of an infiltrated layer with scattered clear or haematic vesicles at the surface. The macro and microcystic forms of LM frequently occur in association, particularly in cases of visceral lesions or when they occur in facial or buccal regions. The majority of lesions are either present at birth or detected before 2 years of age. The lesions are cutaneous and/or mucosal. Visceral forms are rare. LMs are always more extensive than predicted during the clinical examination. Latent cysts may develop at any time. Macrocystic LMs form soft masses, which are generally translucent and sometimes uneven, under normal skin. Intracystic bleeding may lead to pain and hardening. Macrocystic LMs most frequently occur in the axillary regions and neck. Prenatal diagnosis is possible by ultrasound from the fourth month of pregnancy. The size and extensiveness of voluminous lesions, together with assessment of the need for caesarean delivery can be estimated more accurately by magnetic resonance imaging (MRI) conducted in the third trimester. After the birth, ultrasound, computed tomography (CT) scan and MRI are all equally effective means of detecting fluid-containing lesions, but puncture and cytological analysis of the fluid collected is recommended in cases of atypical masses to eliminate the possibility of the presence of another type of lesion. Various sclerosants (Ethibloc, inactivated OK 432, Picibanil, 100% ethanol) are used as first-line treatments for percutaneous sclerosis. The procedure is straightforward, carried out under general anaesthesia and can be repeated. Surgery is usually a second-line treatment, used when sclerotherapy is unsuccessful. The microcystic forms of LM are characterised by clear or haematic vesicles scattered throughout the invaded cutaneous or mucosal region. Several macrocysts may also be present. Profound lesions may lead to disfigurement if localised to the face or appear as pseudotumoural masses if localised to the limbs. Visceral thoracic forms and, in particular, lesions located in the abdominal and pelvic region are rare but their diagnosis and treatment is problematic as they are associated with an abdominal mass and pain, intestinal occlusion due to volvulus, and protein-losing enteropathy with loss of proteins. MRI is the best method for determining the extent of the microcystic LMs. Microcystic lesions can not generally be cured during childhood and recurrence occurs even in cases where resection appeared to be complete. The volume of the microcystic LMs increases during the inflammatory phase following an infectious episode or trauma. Forms affecting the face or buccal mucosa may lead to complications (excessive salivation, halitosis, lingual protrusion, numerous dental cavities) if they become voluminous. During haemorrhage, blood seeps from the cutaneous or mucosal vesicles and ecchymosis is observed. Ocular lesions lead to displacement of the eyeball and may result in diplopia or even proptosis. Haemorrhagic bleeding then occurs in the visceral forms, with chronic consumption coagulopathy leading to a large elevation in the levels of D-dimers and a fall in the level of fibrinogen. Drug treatments (antibiotics, anti-inflammatories, pain killers) are used to combat these complications. Treatment of the lesions is essentially surgical, but this approach is not always feasible. Alternative treatments have been attempted, such as injection of inactivated bacteria or therapeutic approaches using diode and Nd YAG lasers, with the aim of inducing secondary fibrosis. Lymphatic malformations do not present any risk of malignant transformation. |