Pseudoangiosarcomatous squamous cell carcinoma of skin arising adjacent to decubitus ulcers.

Pseudoangiosarcomatous, or pseudovascular, squamous cell carcinoma of skin is an unusual form of acantholytic (adenoid, pseudoglandular) squamous cell carcinoma that mimics the histolopathologic appearance of angiosarcoma. We report a case of pseudoangiosarcomatous squamous cell carcinoma arising adjacent to decubitus ulcers. The histopathologic examination of a wedge biopsy specimen revealed infiltrative cords of neoplastic cells that formed interanastomosing channels imitating angiosarcoma. Immunohistochemical staining was negative for the endothelial markers (CD31, CD34, and factor VIII-related antigen) and positive using cytokeratin antibodies (AE1/AE3 and 34 betaE12). Because of metastatic disease, palliative measures were undertaken and the patient died four months later. To our knowledge, our patient is the first with pseudoangiosarcomatous squamous cell carcinoma of skin developing within decubitus ulcer.