Multiple Symmetric Lipomatosis: New Classification System Based on the Largest German Patient Cohort

Abstract

Background:Multiple symmetric lipomatosis (MSL) is defined as a disorder of nonencapsulated adipose tissue growth. Its prevalence is indicated as 1:25,000 and affects, as stated in the literature, mainly Mediterranean males (male:female ratio of 15:1). Phenotypes are still classified as defined by Donhauser in 1991. We report clinical and phenotypic data of the largest patient cohort investigated in Germany so far.Methods:Forty-five patients diagnosed with MSL at the University Hospital Regensburg between 2007 and 2017 were photographed, clinically examined, and blood samples were taken. Based on the photographs (n = 33), 11 independent observers assessed patients using the Donhauser classification. Furthermore, the bodies of all patients were subdivided into 12 body areas, and the viewers had to indicate all MSL-affected areas per patient. Prevalence was calculated, comorbidities were assessed, and blood samples were analyzed.Results:According to the established Donhauser classification, less than 50% of the patients could be classified. Therefore, based on the constellations of MSL-affected body areas, a new classification that divides phenotypes of MSL into 5 types (Ia, Ib, Ic, II, and III) was set up and was able to cover 100% of our patients. The male to female ratio was found to be 1:2.5 (male:female). Prevalence of MSL in the catchment area was found to be 1:25,000. Hypercholesterinemia and hypothyroidism were frequent comorbidities, and blood analyses were normal besides a hypercholesterinemia.Discussion:The new proposed classification system describes 5 subtypes and allowed to classify all assessed patients. Male to female ratio (1:2.5) contradicted most previous publications.

<p>Cbl Proto-Oncogene B (CBLB) c.197A>T Mutation Induces Mild Metabolic Dysfunction in Partial Type I Multiple Symmetric Lipomatosis (MSL)</p>

“…According to the newly developed MSL classification system, 33 our patients presented as 15.4% Type Ia, 30.8% Type Ib, and 53.8% Type Ic, but there were no Type II or III in these 13 patients. Increase in ATLLM in the P1-P6 and P13 patients resulted in a Type Ic diagnosis in the nuchal region, upper thorax, both upper arms, shoulders, abdomen, and back, while the P7, P8, P9, and P12 patients had a Type Ib diagnosis in the tissues of the nuchal region and shoulders; however, the Type Ia diagnosis only occurred in the nuchal region in P10 and P11 patients ( Figure 1A and B and Table 2 ).…”

“…Abnormal adipose tissue accumulation and distribution are important MSL traits, and, according to the newly developed MSL classification system, 33 MSL can be divided into five types, of which our patients were 15.4% Type Ia, 30.8% Type Ib, and 53.8% Type Ic, but there were no Type II or III patients. To date, there are no effective means to treat or prevent adipose tissue proliferation.…”

“…According to the newly developed MSL classification system, 33 Figure 1A and B and Table 2). Furthermore, the CT or MRI images further verified the SATs accumulation in the abdominal level in P1 -P6 and P13 patients, but the visceral adipose tissue did show a significant increase (CT for P8 and P9) and (MRI for P11 and P12; Figure 1C).…”

A case report of Multiple Symmetric Lipomatosis (MSL) in an East Asian Female

“…Daniel et al sub-divided MSL into three types. The morphologic features of this patient’s mass corresponded to type Ib, based on the presence of a mass in the posterior neck region and both shoulders [ 26 ] (Table 2 ). The direction in which adipose tissue spreads is not yet clear [ 27 ].…”

Madelung’s disease: long-term follow-up

“…The different phenotypes and subtypes of the classification (from reference [5] and partially modified) Phenotype I (subtypes: a, b, c), Phenotype II, Phenotype III.…”