Keywords: lipoedema, lipohypertrophy, non-lipoedema obesity, three-dimensional (3D) ultrasound diagnostics
Objective
The diagnosis of lipoedema is based on clinical examination, however, the three-dimensional (3D) ultrasound is very useful, in all clinical stages, in the evaluation of structural assessment of adipo-fascia, having a view on three planes of space with possible processing of the image with suitable software. Moreover, 3D ultrasound is also useful in the evaluation of features of adipo-fascia in lipohypertrophy and non-lipoedema obesity (gynoid), highlighting differences with pure lipoedema.
Material and Method
In this study in progress, it was decided to apply 3D ultrasound diagnostics in the tissue evaluation using an adequate instrument (SonoScape 20-3D - probe17 MHz) through longitudinal-transversal scans on constant bilateral symmetric marker points in patients with lipoedema (38 stage 1, 44 stage 2, 30 stage 3 - all type III - non obese - aged 18-55 years), lipohypertrophy (48 non obese patients aged 18-44 years) and no-lipoedema obesity (34 patients aged 24-52 years - obesisty class I-II) who had arrived at the Pianeta Linfedema Study Center. In this study, chronic venosus disease, due to primary varicose veins or post-DVT disease and primary or secondary lymphoedema were absent in all patients. Moreover, lymphoscintigraphy exam of the lower limbs was required for the evaluation of the lymphatic system in order to explain some ultrasound features in clinical stages 2 and 3 of pure lipoedema.
Results
3D ultrasound diagnostics, regardless of the clinical stage, has highlighted a normal ultrasound representation of the epidermis-dermis complex in all stages as well as the increased thickness of the subcutaneous tissue, due to hypertrophy of the adipose lobules, not adherent to each other but separated by thickened connective septa, more marked in stage 2 and stage 3; moreover the thickness of the fibres that connect the derma to superficial fascia and an irregular profile of the junction dermo-hypodermis

were also noted in all stage. In addition, the 3D ultrasound highlighted fibrotic connective areas in the connective septa that corresponded to the nodule palpable through the skin at the same marker point, whose size varied in relation to the clinical stage. Furthermore, the lobules in a non-homogeneous way, show inside an increased anechogenicity in stage 2 and stage 3, which according to the author could partly due to free fluid and partly linked to glycosaminoglycans in gel phase. In addition, in view of the presence of increased anechogenicity, already in stage 1, due to fluid along the superficial fascial path, as well as the deep one too, the author has carried out an experimental study that has showed that the fluid is bound to the fascia and not free. Besides, in stage 2 and even more in stage 3 it was noted the presence in the septa of increased anechogenicity due to free fluid, probably due to increased fluid upstream as well as the slower radiotracer flow highlighted by lymphoscintigraphy exam, reabsorbed and even if slowly removed by pre-collectors present in the septa. In lipohypertrophy, 3D ultrasound diagnostics has highlighted, a normal ultrasound representation of the epidermis-dermis complex, a slight irregular profile of the junction dermo-hypodermis, and, although less evident than in lipedema stage I, increased thickness of subcutaneous tissue was found, due to hypertrophy of the adipose lobules as well as the anechogenicity also if fewer evident along the less thickened superficial and depth fascia. In non-lipedema obesity normal ultrasound representation of the epidermis-dermis complex as well as the increased thickness of the subcutaneous tissue due to hypertrophy of the adipose lobules were highlighted, but the non-homogeneous anechogenicity inside the lobules was not highlighted; furthermore an increased anechogenicity due to free fluid in the septa, very marketed evident in the deep region of the subcutaneous tissue above the deep fascia along which, next to the ankle, an anechogenicity for free fluid was highlighted.
Conclusions
High-quality three-dimensional (3D) ultrasound diagnostics resulted in being considerably useful in the evaluation of lipoedema tissue, because it provides important structural details of adipo-fascia, while lymphoscintigraphy exam could explain some ultrasound features in the 2 stage and 3 stage not evident in stage 1. Furthermore 3D ultrasound diagnostics is useful in differential diagnosis between pure lipoedema and lipohypertrophy even if the presence of similar, although less marked, features of lipohypertrophy compared to lipoedema stage 1, makes one reflect on the possibility that this 3D ultrasound image could have a tissue structural evolution into lipoedema. Furthermore, in no-lipedema obesity 3D ultrasound diagnostics highlights similar features to lipoedema stage 3 about the septa, although more marked in the deep region of the subcutaneous tissue above the deep fascia, but differs in the absence of anechogenicity within the adipose lobules compared to lipedema.