Rare adipose disorders (RADs) masquerading as obesity

Abstract

Rare adipose disorders (RADs) including multiple symmetric lipomatosis (MSL), lipedema and Dercum's disease (DD) may be misdiagnosed as obesity. Lifestyle changes, such as reduced caloric intake and increased physical activity are standard care for obesity. Although lifestyle changes and bariatric surgery work effectively for the obesity component of RADs, these treatments do not routinely reduce the abnormal subcutaneous adipose tissue (SAT) of RADs. RAD SAT likely results from the growth of a brown stem cell population with secondary lymphatic dysfunction in MSL, or by primary vascular and lymphatic dysfunction in lipedema and DD. People with RADs do not lose SAT from caloric limitation and increased energy expenditure alone. In order to improve recognition of RADs apart from obesity, the diagnostic criteria, histology and pathophysiology of RADs are presented and contrasted to familial partial lipodystrophies, acquired partial lipodystrophies and obesity with which they may be confused. Treatment recommendations focus on evidence-based data and include lymphatic decongestive therapy, medications and supplements that support loss of RAD SAT. Associated RAD conditions including depression, anxiety and pain will improve as healthcare providers learn to identify and adopt alternative treatment regimens for the abnormal SAT component of RADs. Effective dietary and exercise regimens are needed in RAD populations to improve quality of life and construct advanced treatment regimens for future generations.

Figure 1

Multiple symmetric lipomatosis with or without HIV infection. A and B, non-HIV-related MSL Type II; note increased upper arm size and increased fat on back. Not shown is increased fat in the labia majora. C and D, increased arm and back fat, respectively in HIV-and HAART-induced MSL Type II. Arrows point to end of MSL fat on the upper arm. Normal labia majora (not shown).

Figure 2

Acquired partial lipodystrophy and lipedema. A, a 37 year old woman with acquired partial lipodystrophy. C3 level<16.1 mg/dL (normal range: 90-180) and C4 level 23.11 mg/dL (normal range: 10-40). Note the loss of SAT from the upper body to the waist but obesity of the hips and legs (photo by Dr Alper GURLEK). B, a woman with lipedema stage II and a previous history of obesity with a 100 kg weight loss; note redundant skin on arms and abdomen from weight loss of non-RAD fat; note also lipedema in legs.

Figure 3

Whole body MSL and MSL-associated lipodystrophy. While MSL is noted to spare the forearms (see text), the entire body can be clearly affected. A, 60 year old woman with a history of alcohol dependence with global MSL SAT; note prevalent SAT on the forearms (photo by Dr Andy COREN). This type of MSL may be easily confused with global obesity or lipedema stage III. B, 50 year old man with MSL Types I and II with associated muscle and normal fat atrophy (also note the increased back MSL SAT; arrows); this type of MSL may be confused with partial lipodystrophy.

Figure 4

The three stages of lipedema. A, Stage I with little alteration of the skin surface. B, In stage 2, the surface of the skin takes on the appearance of a mattress with lipomas in the fat. C, In stage III lipedema, there are much larger fat extrusions.