Poorly differentiated plasmacytoid squamous cell carcinoma: Case report of a rare malignancy

Plasmacytoid squamous cell carcinoma is an especially aggressive variant of squamous cell carcinoma that has previously been described in the literature as a variant of oral cancers and most extensively, in vulvular [3], transitional cell, and urothelial carcinomas [2,13,15-20]. In this case report, we present a 36-year-old man with 6 to 8 weeks of a progressively enlarging mass over the lateral third of his clavicle, acromion process, and deltoid. The mass was resected, and the supraclavicular defect was reconstructed using an anterolateral thigh free flap. Final pathology determined the specimen was an invasive poorly differentiated squamous cell carcinoma with spindle cell and plasmacytoid features of cutaneous origin. Plasmacytoid squamous cell carcinomas have previously been described in the oral cavity, but in no other subsite of the head and neck. This article describes the patient's case and provides a literature review of the available reports related to plasmacytoid variant of squamous cell carcinoma.