Solitary fibrous tumor/hemangiopericytoma of the external auditory canal

Abstract Introduction: Solitary fibrous tumor/hemangiopericytoma is an uncommon neoplasm that accounts for only 1–2% of all soft tissue tumors. To the best of our knowledge only three cases of this tumor have been described in the external auditory canal in the past. Case presentation: We report the case of a 60 years old man with a 6 months history of progressive swelling of the left auditory canal. After resection under general anaesthesia, the immunohistochemical staining showed positivity to CD34, CD99, vimentin and bcl2 with the typical spindle-shaped cells organized in a patternless pattern. The tumor was also positive to specific STAT6 nuclear expression. Therefore, the diagnosis of solitary fibrous tumor/hemangiopericytoma was made. Conclusions: The possibility of a STF/HPC should be considered among the differential diagnosis of tumors in the external auditory canal and, due to its malignant potential, a close and long follow up should be done in all the patients.