cardiovascular disorders
Lymphedema
Etiology of Lymphedema
Lymphedema may be Primary: Due to lymphatic hypoplasia Secondary: Due to obstruction or disruption of lymphatic vessels Primary lymphedemas are inherited and account for < 5% of cases of lymphedema. They vary in phenotype and patient age at presentation but mostly involve the lower extremities. Congenital lymphedemaappears before age 2 years and is due to lymphatic aplasia or hypoplasia.Milroy diseaseis an autosomal dominant familial form of congenital lymphedema attributed to vascular endothelial growth factor receptor-3 (VEGFR-3) gene mutations and sometimes associated with cholestatic jaundice and edema or diarrhea due to a protein-losing enteropathy caused by intestinal lymphangiectasia. Lymphedema praecoxappears between ages 2 and 35, typically in women at the onset of menses or pregnancy. Meige diseaseis an autosomal dominant familial form of lymphedema praecox attributed to mutations in a transcription factor gene (FOXC2) that causes extra eyelashes (distichiasis), cleft palate, and edema of legs, arms, and sometimes the face. Lymphedema tardaoccurs after age 35. Familial and sporadic forms exist; the genetic basis of both is unknown. Clinical findings are similar to those of lymphedema praecox but may be less severe. Lymphedema is prominent in some other genetic syndromes, including Turner Syndrome None Nail deformities and dystrophies associated with systemic problems , Hennekam syndrome,a rare congenital syndrome of intestinal and other lymphangiectases, facial anomalies, and intellectual disability Secondary lymphedema accounts for > 95% of cases. Most common causesare Surgery (especially lymph node dissection, typically for treatment of breast cancer) Radiation therapy (especially axillary or inguinal) Trauma Lymphatic obstruction by a tumor Bancroftian and Brugian Lymphatic Filariasis (present in some tropical and subtropical areas) Mild lymphedema may also result from leakage of lymph into interstitial tissues in patients with Chronic Venous Insufficiency and Post-Thrombotic Syndrome . 