Carcinoma en cuirasse (CEC, also known as scirrhous carcinoma, pachydermia, and Acarcine eburnee) is a rare, aggressive form of cutaneous cancer metastasis with poor prognosis. It usually represents a tumor recurrence but occasionally it can present as an initial finding before diagnosis of a primary malignancy. The most common cancer to present with CEC is breast cancer. CEC has also been rarely seen in the setting of primary lung cancer, gastrointestinal cancers, and genitourinary malignancies.

CEC most commonly occurs on the anterior chest wall but occasionally has been reported to involve the abdomen and rarer sites, including the scrotum. CEC is described as encasing the body in breastplate armor (en cuirasse). It is characterized initially by small papules and nodules that coalesce to form indurated, sclerotic plaques. CEC can then progress to restrict movement of the chest wall and impede respiration.

These skin findings may be associated with pruritus, pain, bleeding, or a foul-smelling discharge.