Desmoplastic Fibroblastoma of the Scalp Accompanied by Severe Pain; Unusual Location and Symptom

Desmoplastic fibroblastoma is a rare fibrous tumor that usually presents as a painless, slow-growing mass in the subcutaneous tissues and skeletal muscles. It has a wide anatomic distribution, with the most common involvement being the arm and shoulder. Here, we report a case of a tiny painful desmoplastic fibroblastoma arising on the scalp. According to a microscopic examination, this tumor was composed of spindle-shaped fibroblasts in the dense collagenous stroma. On immunohistochemical staining, tumor cells were positive for vimentin and negative for smooth muscle actin, CD34, and S100. Our case is unique in that desmoplastic fibroblastoma developed on the scalp and there was presence of pain despite its small size.