Benign symmetric lipomatosis

Benign symmetric lipomatosis, also known as Madelung's disease, is an adult-onset skin condition characterized by extensive symmetric fat deposits in the head, neck, and shoulder girdle area.^[1] The symmetrical fat deposits are made of unencapsulated lipomas, which distinguishes it from typical lipomatosis which has encapsulated lipomas that are not usually symmetrical.^[2] Benjamin Brodie described the condition in 1846. The German surgeon Otto Wilhelm Madelung was the first to give a detailed description of the disorder in 1888, followed by Launois and Bensaude in 1898.^[3]

Benign symmetric lipomatosis
Other names	Benign symmetric lipomatosis of Launois–Bensaude; Madelung's disease; multiple symmetric lipomatosis; cephalothoracic lipodystrophy; symmetrical adenolipomatosis; fat neck (Fetthals)
A young man with benign symmetric lipomatosis (Madelung's disease) of unknown cause exhibiting Madelung's collar and buffalo hump
Specialty	Dermatology, endocrinology
Usual onset	Adult-onset

This condition is rare, with an estimated incidence of 1 in 25,000 in Italy.^[3][4] Older research found that it affects males up to 15 - 30 times more frequently than females;^[3][4] however, more recent studies have found a higher prevalence among women than men (1:2.5) and so further epidemiological studies are needed.^[4] It predominantly affects those of the Mediterranean and European populations, although rare cases have been documented outside of those populations^[5] (such as Ethiopian,^[6] Chinese,^[7] Mexican-American,^[8] Indian,^[2] African-American,^[9] and African-Indian^[10]).

Large fat deposits around the neck, and more rarely in the tongue, may negatively affect breathing, swallowing, and speaking.^[11][12] Orbital involvement is very rare, with proptosis (bulging of the eye) and persistent bilateral lumps on the eyelids.^[13][14]

Comorbidities frequently involve the endocrine systems, with hypercholesterinemia and hypothyroidism being the most common.^[13][4] Other comorbidities include diabetes mellitus, hypertension, and gout.^[5][4] In individuals with alcohol use disorder, there is also alcohol-related cirrhosis of the liver.^[5][4] There have also been reports of peripheral neuropathy, ragged red fibres in muscle cells (suggesting mitochondrial myopathy), sudden cardiac death, and neurological involvement, although it is unknown whether these are due to prolonged alcohol use disorder as such symptoms of mitochondrial dysfunction also appear in alcoholics without Madelung's disease.^{[5][4][15][16]} However, rarely, instances of mitochondrial dysfunction (high lactate/low pyruvate, polyneuropathy, decreased cytochrome c oxidase and abnormal mitochondria) have been documented in non-alcoholics with Madelung's disease.^[2][15][16]

Cosmetic disfigurement due to the fat deposition in the cervicothoracic region results in a "pseudoathletic appearance," resembling the Italian statue Warrior of Capestrano and carvings of Queen of Punt (Egypt).^[10][17] The fat deposited around the front of the neck is known as Madelung's collar or horse collar.^[13][5] Fat deposited on the back of the neck between the shoulder blades is known as a dorsocervical fat pad or buffalo hump.^[13][18] Fat deposited in the parotid region is known as hamster cheeks.^[10]