T3, T4 and TSH
Thyroid and thyroid stimulating hormones, respectively. They must be assessed in all patients with peripheral edemas, because of a likely mixedematous component and the influence of thyroid hormones on body metabolism and homeostasis at the level of the interstitium and peripheral tissues.
Autosomal dominant myotonia congenital due to mutations in the chloride channel. It presents with a picture of widespread and progressive myotonia. As is often the case in neurological-muscular disorders, it can be associated with functional disuse lymphedema caused by muscular hypotonia.
Figure: Eye-lid edema caused by a deficiency of the elevator muscle of the upper eyelid, in an exemplary case of Thomsen’s myotonic syndrome.
The largest lymphatic vessel in the body (with a 5-8 mm gauge) and the most important pathway draining the lymph into the venous bloodstream. It originates from the confluence of the intestinal lymphatic trunk and right and left lymphatic lumbar trunks at the level of the first-second lumbar vertebra. In its initial portion, it may feature an ampulla-shaped dilation called chylous cyst or receptaculum chyli of Pecquet (see). After running posteriorly to the esophagus for about 35-45 cm, between the azygos vein (on the right) and the aorta (on the left), it empties into the left subclavian vein at the level of the homolateral subclavian-jugular angle. In its final portion, the thoracic duct runs to form an anterolateral, concave arch, branching out in different ways.
Genetic disorder linked to the total absence of a sexual chromosome (kariotype 45,X : 50%) or mosaicism (45,X/46,XX : 25%) or to X- chromosome anomalies (46,XX : 25%), with the following clinical manifestations: primary amenorrhea, sexual infantilism, short stature, other associated congenital anomalies (including, in many cases, a primary lymphedema of the lower limbs).