Dercum disease
Dercum disease, also known as adiposis dolorosa, is a rare disorder of subcutaneous tissue characterized by multiple painful lipomas.
Epidemiology
Although the exact incidence is unclear, Dercum disease affects women more than men . It is usually sporadic, however, autosomal dominant forms with incomplete penetrance have been described, but these are thought to make up only a minority of all presentations .
Clinical presentation
The primary presenting feature in patients with Dercum disease is multiple painful and tender lipomas that may be located anywhere on the body, although legs and trunk are the most common locations . The pain associated with these lipomas can often be severe and may be either constant or intermittent .
In association, patients often describe :
- obesity
- generalized weakness and fatigue
- psychological complaints
Pathology
It is unclear if Dercum disease has any defining pathological features. Studies examining the painful lipomas histologically vary in their findings, with some describing essentially unremarkable lipomatous changes while others revealing inflammatory changes . Even in cases with inflammatory features, it is unclear if this inflammation is significant in relation to the pain experienced by patients with Dercum disease because such features can be seen in ordinary non-painful lipomas in a similarly obese demographic . It has been postulated that instead of inflammation, perhaps these lipomas impinge on nerves or perhaps there is an autoimmune component, however neither theory has garnered much evidence .
Radiographic features
Radiographic features are generally almost indistinguishable from ordinary lipomas (see lipoma for in-depth discussion of radiographic features) . Important features which may indicate a diagnosis of Dercum disease include:
- very numerous lipomas, although interestingly only a small number are symptomatic
- lipomas are relatively small in size, generally <2 cm in diameter
- symptomatic lipomas are generally larger in size than their asymptomatic counterparts
- symptomatic lipomas may be tender with an ultrasound probe
- lipomas are generally restricted to the superficial subcutaneous layer
- no edema is appreciated around the lipomas on any imaging modality
- occasionally, lipomas will resemble angiolipomas radiographically instead
Treatment and prognosis
No specific treatment exists, and thus management revolves around symptom control . This may include, but is not limited to, analgesics, surgical excision of troublesome lesions, and psychotherapy .
History and etymology
The disease was discovered by its eponym Francis Xavier Dercum (1856-1931), an American neurologist, in 1892 . Interestingly, in his seminal paper, he described the lesions as “irregular and even capricious in these cases, but there is, in addition, another important factor to be remembered, and that is: that at some time or other, the enlargement is accompanied by pain", a description which remains characteristic of the disease to this day .
Differential diagnosis
It is important to distinguish Dercum disease from other conditions associated with subcutaneous lipomas such as:
