Dercum's disease: a rare and underdiagnosed disease.

Dear Editor,

Dercum's disease, or adiposis dolorosa, is a rare entity, characterized by overweight or obesity and the appearance of multiple painful lipomas, mainly in the upper limbs and trunk. By definition, the pain is chronic, with a duration of at least 3 months, symmetrical and generally resistant to conventional analgesics.[1] We report a typical case, with a good response to the surgical treatment, of a 76-year-old female, menopausal, obese (BMI=37) patient with arterial hypertension, hypertriglyceridemia and glaucoma, with painful nodules on the back and upper limbs for approximately twenty years. She reported growth of some nodules and increase in number over time. In the investigation of other symptoms, she denied depressive symptoms, chronic fatigue or associated sleep disorders. She reported only severe pain in three upper limb nodules and one in the back. On physical examination, she presented skin-colored subcutaneous nodules all over the upper limbs and on the back (Figures 1 and 2). Surgical removal of the painful nodules and anatomopathological examination were performed, which confirmed the proliferation of well differentiated and uniform adipocytes, sitting on a fibrovascular network, confirming the diagnosis of lipomas (Figure 3). After the surgical procedure, the patient had improvement in the pain and remains in outpatient care, with no signs of recurrence after 7 months of follow-up.

Figure 1

Nodules covered by normal-looking skin all over the upper limbs

Figure 2

Nodules covered by normal-looking skin all over the upper limbs

Figure 3

Photomicroscopy of a subcutaneous lesion. Mature adipose tissue with many capillaries (Hematoxylin and eosin, x100)

Dercum's disease is a rare entity, and the different treatment strategies that exist are based on case reports, which justifies the importance of this report. Its exact pathophysiology is unknown, but several pathogenic hypotheses have been presented, including abnormalities in carbohydrate metabolism and decreased conversion of glucose to triglycerides in painful adipose tissue. Endocrine disorders have also been reported and pain may be related to microthromboses or peripheral nerve abnormalities.[1]-[3]

It is inherited in an autosomal dominant pattern, with variable penetrance, but most cases are sporadic.[1] It mainly affects women in the postmenopausal period and is 5 to 30 times more frequent in females. Exact prevalence has not yet been defined.[1],[4] The diagnosis is clinical and rest on basic criteria that include overweight or generalized obesity and chronic pain (> 3 months) in the adipose tissue.[1],[5] In the past, asthenia and psychiatric symptoms such as depression, emotional instability and sleep disturbances were considered as cardinal symptoms and were part of the diagnostic criteria. However, because they were not found in all cases and it was difficult to establish their real relationship with the disease, now they are considered as symptoms correlated with adiposis dolorosa.[1] Based on the distribution of the affected adipose tissue and the association with lipomas, Dercum's disease is classified into 4 types: generalized diffuse (very painful adipose tissue without lipomas), generalized nodular (generalized pain in the adipose tissue, more intense inside and around the lipomas), localized nodular (painful adipose tissue exclusively within and around lipomas) and juxta-articular (deposition of painful solitary fat in the proximity of large joints).[2] The treatment aims to relieve pain and correct disfigurement. Medications, surgery and psychiatric care should be used in combination. Among the therapeutic options are the use of analgesics, non-steroidal anti-inflammatory drugs and opioids with variable response. The use of intralesional lidocaine in the form of adhesives or intravenous, seems to alleviate pain by regulating a possible hyperactivity of the sympathetic nervous system.[1],[3] Liposuction and lipectomy are effective in reducing symptoms and have the same efficacy in removing lipomas, alleviating pain and correcting disfigurement and associated psychiatric disorders, but with a risk of recurrence.[1] About the prognosis, there is little research done on the natural history of Dercum's disease, but case reports have suggested that pain may be aggravated over time.[1] There is a need to become familiar with this entity so that it is not an underdiagnosed condition anymore.[4]

This report describes a typical presentation of Dercum's disease in a female, obese and menopausal patient, with the development of painful lipomas mainly in the extremities and trunk, who had satisfactory control of symptoms with lipectomy. An overview of the pathogenesis, diagnosis and treatment of this rare and poorly understood disease is also presented. Because it is a rare disease with limited therapeutic options, the treatment modality chosen in this case is presented, which yielded a good result. The importance of new studies is also emphasized, which may help to understand its real etiology and the implementation of treatments capable of acting early, blocking the pathophysiological mechanisms.