Histiocyte-rich Discoid Lupus Erythematosus: A Peculiar Perifollicular Distribution Histologically Mimicking an Acneiform Disorder.

The histologic profile of discoid lupus erythematosus typically involves a vacuolar interface reaction with an associated superficial and deep perivascular infiltrate composed of lymphoplasmacytes. We present a unique case of discoid lupus erythematosus in which cluster of differentiation 68 (CD68) immunochemistry identified widely dispersed histiocytes. Few reports of histiocyte-rich cutaneous lupus erythematosus exist in the literature, and these lymphohistiocytic infiltrates, when present on the H-zone of the face, could be misconstrued as acne/rosacea. Our case demonstrates that cutaneous lupus erythematosus can present with a predominantly histiocytic infiltrate, a pattern dermatopathologists should be aware of to avoid non-recognition or misdiagnosis.