Abstract
A 63-year-old male presented with a painful skin lesion on the left side of the neck and upper chest approximately two months prior to presentation. Diffuse erythematous to purplish-colored sclerotic patches were observed. He had been treated with intravenous antibiotics for two weeks for cellulitis, but the lesion did not improve. Punch biopsy, and neck computed tomography (CT) with contrast enhancement were performed to differentiate between cellulitis and scleroderma. Histopathological examination revealed infiltration of pleomorphic and poorly differentiated tumor cells extending into thickened collagen bundles, and mitotic activity. Based on histologic and radiologic findings, the patient was suspected to have poorly differentiated carcinoma, and further evaluation of the origin of the carcinoma was performed. A subareolar mass on the left breast was observed on chest CT, and a needle biopsy was performed; results were consistent with findings from the skin biopsy. Finally, the patient was diagnosed with carcinoma en cuirasse, a subtype of cutaneous metastasis of breast cancer, was transferred to oncology, and underwent palliative chemotherapy.