Histology of adipose tissue inflammation in Dercum's disease, obesity and normal weight controls: a case control study

BACKGROUND: Dercum's disease (DD) is characterised by obesity and chronic pain (> 3 months) in the adipose tissue. The pathogenesis of DD is unknown, but inflammatory components have been proposed. In previous reports and studies, an inconsistent picture of the histological appearance of the adipose tissue in DD has been described. The aim of this investigation was to examine the histological appearance of adipose tissue in patients with DD, with particular focus on inflammatory signs. METHODS: Fat biopsies were sampled from painful regions from 53 patients with DD. In 28 of the patients, a control adipose tissue biopsy was taken from a location where the patient did not experience any pain. In addition, fat biopsies were sampled from 41 healthy pain-free obese control patients and 11 healthy pain-free normal weight control patients. The extent of inflammation was evaluated on histological sections stained with haematoxylin-eosin. RESULTS: There was no statistically significant difference in the extent of inflammation between the biopsies from the painful knee and the biopsies from the non-painful area (p = 0.5), nor between the biopsies from the abdomen, and the biopsies from the non-painful area (p = 0.4), in patients with DD. A statistically significant difference in extent of inflammation was observed between DD and obese control patients regarding the abdomen (p = 0.022), but not the knee (p = 0.33). There were no differences in extent of inflammation between DD patients and normal weight controls (p = 0.81). CONCLUSION: The findings suggest that there is an inflammatory response in the adipose tissue in DD. However, this response is not more pronounced than that in healthy obese controls. This contradicts inflammation as the aetiology of DD.