Images in vascular medicine. Lymphoscintigraphy in congenital lymphedema.

Abstract

Slight degrees of congenital lymphedema are not infrequently reported in the pediatric population. These findings probably reflect a normal developmental variation in the regression of lymphedema that is postulated to be present in all fetuses.1,2 However, more severe degrees of lymphedema in childhood are much less common, and frequently reflect the impact of infection, trauma, neoplasia and radiation.3 Severe congenital lymphedema is most often ascribable to heritable syndromes of genetic origin, such as Nonne–Milroy disease, lymphedema with microcephaly,6,7 Noonan syndrome,8,9 Ullrich Turner syndrome,10 lymphedema-hypoparathyroidism syndrome11 and the more recently described Hennekam syndrome.12 Most of these syndromes display an autosomal dominant pattern of inheritance. Many of the associated somatic defects, such as hypertelorism, ear anomalies, epicanthal folds and retrognathia, might conceivably be explained by lymphatic hypoplasia as a consequence of intrauterine lymphedema. In many such patients, the identification of heritable syndromes depends heavily on the accurate diagnosis of congenital lymphedema. While this can often be accomplished with routine physical assessment, at times the findings of indirect radionuclide lymphoscintigraphy can provide valuable confirmatory evidence. The figure depicts the lymphoscintigraphic findings in a 13-year-old female with severe, congenital lymphedema and associated developmental defects. The study demonstrates extensive stasis of the radionuclide within the cutaneous structures of the lower extremities (‘dermal backflow’) and the popliteal lymph nodes are distinctly delineated with radionuclide uptake. The latter finding suggests lymphatic transport via the deep lymphatic system;14 both findings are characteristic of lymphatic insufficiency and lymphostasis.