Endocrine Abstracts

Introduction: Necrobiosis lipoidica (NL) is a rare, chronic granulomatous cutaneous disease that most often affects the lower extremities. The etiology of the condition is unknown but there appears to be some association with diabetes mellitus. Perforating necrobiosis lipoidica (PNL) is a very rare variant of NL characterized by trans-epidermal collagen elimination. We present a case of type II diabetes patient with disseminated perforating necrobiosis lipoidica (PNL).

Case report: A 52-year-old female patient suffering from long-term diabetes mellitus type II, controlled with insulin, was referred to our clinic. She complained of multiple asymptomatic firm plaques on the lower extremities that appeared about 3 years ago. These plaques started as painless, reddish papules that slowly enlarged formatting indurated centrally depressed plaques. The clinical examination revealed infiltrated plaques disseminated on the extensor surfaces of the lower extremities. The lesions were presented by brown-yellow plaques with irregular shape, slightly elevated border, and atrophic center focally studded with comedo-like papules. Microscopic examination of the lesions demonstrated a degenerated collagen and fibrosis with peripheral lymphohistiocytic infiltrate and transepidermal elimination of necrotic material. The clinical and histologic diagnosis was perforating necrobiosis lipoidica. Initiated treatment with topical steroids was ineffective. Intralesional corticosteroid therapy demonstrated a significant improvement in the appearance of the cutaneous lesions. Diabetes self-management education was also reinforced.

Discussion: Necrobiosis lipoidica, first described by Oppenheim in 1929, is a chronic granulomatous disorder, strongly associated with diabetes. It has a prevalence of 0.3 percent of the diabetic adult population. NL often presents as slowly expanding violaceous patches located mostly on the lower legs. The advancing border is usually red with a yellow brown central area. The central areas are atrophic and have a waxy surface with telangiectasias.In approximately 85% of cases, the legs are exclusively involved. Perforating necrobiosis lipoidica (PNL) is a rare variant of NL that is almost always associated with diabetes. The histopathology of NL is a granulomatous dermatitis associated with degeneration of dermal collagen, histiocytes arranged in a palisade around zones of necrobiosis and interstitially between collagen fibres.The perforating variants show transepithelial elimination of necrotic material. Few cases of PNL have been reported in the literature. Treatment of both NL and PNL is often unrewarding. Some improvement with intralesional corticosteroid has been reported, as seen in the patient described here.

Conclusion: Perforating necrobiosis lipoidica is a rare variant of NL, which occurs mostly in diabetic patients. Although the disease has benign course, the treatment is still remains a challenge.