The histology of cellulite was first described by Nurnberger and Muller in 1978, who attributed cellulite formation to sexually dimorphic skin architecture. They hypothesized that cellulite is determined by fatty protrusions through the dermal-hypodermal interface, and reported that these deep adipose indentations were present in the dermis of women, but not of men [2]. Rosenbaum’s results substantiated the latter’s claims when they discovered that female subjects, both with and without cellulite, exhibited a discontinuous and irregular dermo-hypodermal interface characterized by adipocyte protrusion into the dermis. On the contrary, the connective tissue dermal-adipose tissue border in male subjects was continuous and even [8] (Fig. 16.3). Pierard et al. [9] found no correlation between a clinical evidence of cellulite and papillae adiposae, and thus questioned Nurnberger’s claims. Instead, they hypothesized that cellulite results from the stretching of fibrous septae, which in turn, causes the connective tissue support to deteriorate, allowing fat herniation.
Around 1978, Nurnberger and Muller also differentiated between the dermo-hypodermal interfaces of women versus men. They attributed cellulite formation to the sexually dimorphic skin architecture of the fibrous septae, where dermal herniations of subcutaneous fat occur mainly in women due to vertical fascial bands. The fibrous septae of men take on a criss-cross pattern of 45° tilted planes which they claimed, is more resistant to fat herniations. Further, according to these studies, female fat lobules are larger than those in males and are compartmentalized by fibrous septae oriented perpendicular to the dermis. This orientation makes it easier for fat lobules to protrude vertically into the dermis, perpetuating fat herniations and a dimpled cutaneous surface. In contrast, the smaller male fat lobules are separated by obliquely arranged septae, thus preventing herniation [2].
The hypotheses of Nurnberger and Muller have been both supported and refuted since the inception of in vivo imaging methods. Querleux et al. were the first to employ magnetic resonance imaging (MRI) to visualize the 3-dimensional architecture of the fibrous septae [10]. Magnetic resonance imaging evidenced for the first time that women with cellulite had a
significantly thicker inner fat layer compared to normal women (p<0.01). In addition, the adipose layers of women with cellulite are significantly thicker compared to normal women or men (p=0.0001).
The results of MRI have challenged some of Nurnberger’s claims. Using MRI on women with cellulite, Querleux et al. also found a smaller percentage of fibrous septae parallel to the skin surface, but a higher percentage of septae perpendicular to the surface [10]. These results are partly in harmony with Nurnberger’s hypotheses, but demonstrate that the declarations of the latter (perpendicular pattern in women and criss-cross pattern in men) may be a bit of an oversimplification. MRI gives strong evidence that the directions of the fibrous septae network are more heterogeneous than originally theorized.