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

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.