A granulomatous conundrum: Concurrent necrobiosis lipoidica, cutaneous sarcoidosis and erythema nodosum in a nondiabetic patient

Abstract

Necrobiosis lipoidica (NL) and cutaneous sarcoidosis are granulomatous disorders with a largely unknown aetiopathogenesis. Evidence of co-existing NL and sarcoidosis in the same patient may suggest a degree of overlap between these entities through shared granulomatous inflammatory pathways. Occasionally, one condition can mimic the other, making their distinction difficult. We report a novel case of a non-diabetic woman who presented with concurrent NL, cutaneous sarcoidosis and erythema nodosum. We discuss some of the complexities distinguishing these entities and propose that they may represent different stages of the same granulomatous process linked through yet unknown pathomechanisms.

Necrobiosis lipoidica associated with sarcoidosis

“…Sixteen cases were identified in which a patient with systemic sarcoidosis developed atrophic plaques on the skin consistent with a clinical impression of NL. However, only 10 patients were histologically diagnosed as NL (Table ), while six were diagnosed as cutaneous sarcoidosis mimicking NL (Table ) . Of note, this raises the possibility that the unbiopsied lesions on our patient and others from the literature cannot be assumed to also be NL just by clinical appearance.…”

“…Three of these patients also had typical cutaneous sarcoidosis, which improved on prednisone. NL improved only in two cases, with fluocinonide 0.05% cream after failure of prednisone, and with oral pentoxifylline 400 mg three times daily after failure of prednisone and medium‐potency topical corticosteroids …”

“…Valecha et al presented a patient with clinical and histological NL on her shins that coexisted with erythema nodosum in the same area, as well as violaceous papules on the knees that appeared to be sarcoidosis on histology but had subtle necrobiosis. The authors remarked that her knee lesions might have represented an earlier stage of her NL lesions.…”

“…Very rarely, sarcoidosis and NL have also been reported to develop in the same patient. Ten of these cases have been documented in the literature . Interestingly, there are also six cases of sarcoidosis patients who developed skin lesions that appeared and behaved like NL clinically, but were diagnosed as sarcoidosis histologically .…”

Necrobiosis lipoidica‐like lesions in a nondiabetic patient with systemic sarcoidosis: A case report and review of the literature

“…Sarcoidosis and necrobiosis lipoidica (NL) are noninfectious granulomatous disorders with unknown etiologies. 1 Sarcoidosis is a systemic disease with the hallmark of noncaseating granuloma formations. Red-brown papule or plaques, erythema nodosum, and lupus pernio are the different cutaneous presentations of sarcoidosis.…”