Membranous lipodystrophy associated with insulin lipoatrophy

A 60-year-old Korean woman had been diabetic since she was 40 years old. Initially, she was injected with beef insulin; after a few years of good response, her blood sugar became erratic and uncontrollable. Purified pork insulin was added. She had been receiving daily 55 units NPH purified pork insulin in the AM and 45 units of lente purified insulin in the PM. She was advised and trained to inject at different sites, but she did not necessarily do so, and she had injected repeatedly at the same site on the right buttock. Gradually, atrophic patches developed on the right buttock. On physical examination, two coin-sized, annular, depressed, and atrophic lesions with a hypopigmented surface were seen on the buttock. These were painless and spongy on palpation. She had no history of any vascular or connective tissue disease or evidence of infection or trauma. Laboratory work-up revealed normal complete blood count and differential count and normal urinalysis, and an SMA 18 screen showed a blood sugar of 200 mg/dL. An incisional biopsy was carried out at the site of the right buttock; histologic sections showed numerous lobules of small lipocytes with proliferation of capillaries, degenerative loss of adipose tissue, and multiple cysts of irregular shape and variable size. The wall of the cysts characteristically showed a nuclear, homogeneous, eosinophilic material. There was slight infiltration of mononuclear cells around the blood vessels in the fat lobule (Figs 1-3).