Histology and histomorphometric analysis of the normal and atrophic heel fat pad.

Light and electron microscopy was used for a histologic examination of normal heel fat pads and atrophic heel fat pads from patients with peripheral neuropathies. Histomorphometric analysis revealed an average 30% smaller mean cell area and 16% smaller mean cell diameters in the atrophic pads compared with the normal heel fat pads. Septal walls in the atrophic fat pads were often fragmented and approximately 75% wider than normal. Perineural fibrosis was also found in the atrophic heel fat pads. The Verhoeff elastic staining technique was used to determine the relative percentage of collagen to elastic tissue within the septae. No significant differences were noted between the normal and atrophic heels. The ultrastructure of the adipocytes from the normal and atrophic heel pads was similar to those found in abdominal subcutaneous fat. Lipid droplets of variable size and density thin the center of the adipocyte were surrounded by a thin border of cytoplasm. The interphase between adipocytes contained fine collagen and elastic fibers.