Cutaneous squamous cell carcinoma causing a rhinophymatous mass in a patient with clinically occult hypertrophic lupus erythematosus

Hypertrophic lupus erythematosus is a variant of discoid lupus erythematosus, which manifests as verrucous plaques and/or keratoacanthoma-like nodules on the face and arms. Diagnosis and treatment of hypertrophic lupus erythematosus can be challenging as it can resemble cutaneous squamous cell carcinoma clinically and histopathologically. Furthermore, cutaneous squamous cell carcinoma is a known complication of discoid lupus erythematosus. We present a diagnostically challenging case of a patient with a rapidly enlarging rhinophymatous mass and multiple keratoacanthoma-like lesions of the bilateral upper extremities whose work-up was initially equivocal. CD123 staining helped to elucidate a final diagnosis of cutaneous squamous cell carcinoma arising in a background of occult hypertrophic lupus erythematosus.