Lipodermatosclerosis is a chronic fibrosing process that involves both lower legs and classically affects Caucasian women in their 60s.

The objective is to define the histologic spectrum seen this condition.

A total of 25 cases were collected prospectively and all were stained with hematoxylin-eosin, von Kossa, and Verhoeff-van Gieson.

Patient age ranged from 33 to 84 years (mean age 62.6 years). The female to male ratio was approximately 12 to 1. All lesions were present on the lower extremities, between the knee and ankle. Lesion duration ranged from 2 months to 2 years (mean 9.5 months). Clinically, the lesions were erythematous, tender, indurated plaques or nodules. The characteristic histologic findings were seen almost exclusively in the subcutaneous tissue, involving primarily the lobules but also the septa. Adipose changes included micropseudocyst and macropseudocyst formation, necrotic adipocytes, lipomembranous change, and lipogranulomas with xanthomatous macrophages. The lesions were largely devoid of dermal, septal, or lobular neutrophilic or lymphocytic inflammation. Medium vessel calcification was seen in 13 cases. The accumulation of basophilic elastic fibers located deep in the septa was present in all the cases. These fibers had a moth-eaten appearance and resembled pseudoxanthoma elasticum. In 21 of 25 cases, these fibers were positive with both the von Kossa and Verhoeff-van Gieson stains.

The cases in the series were not compared with age-, sex-, and location-matched biopsy specimens or biopsy specimens of other fibrosing conditions.

This constellation of histologic changes is diagnostic of lipodermatosclerosis. The presence of pseudoxanthoma elasticum–like changes is a helpful, but not unequivocal, clue in this condition.