Neurothekeoma is a very rare benign connective tissue tumour that presumably derived from nerve sheath cells. We described the case of a rare localization of neurothekeoma in the upper limb with a strange presentation. A 49 years-old woman presented to the Physical Medicine and Rehabilitation Division of the Umberto I Hospital referring an intensive pain associated to paresthesias at the left forearm lasting from six months. The patient had a history of epicondylitis confirmed with an elbow RMN showing an increased thickness of the tendon insertions on the epicondiloidea region of the elbow. Rehabilitative and physical therapy has been done without symptoms remission. An ultrasound evaluation showed an oval formation well circumscribed in the context of the radial nerve. It was easy to demonstrate the relevance of the radial nerve, following it from the arch of Frohse until the humeral sulcus of the radial nerve. A MRI that showed a mass, mildly hypointense on T1- weighted sequences and hyperintense on T2-weighted images, with nonhomogeneous enhancement post-contrast, attributable to expansionary pathology of the radial nerve. A biopsy was done and the lesion was described as a benign tumor of nerve sheath, i.e., a Neurothekeoma of the radial nerve. Patients was surgically treated, the tumor has been removed and she referred the resolution of symptomatology.
Keywords: Myxomas of nerve sheath; Neurothekeoma; Radial nerve; Upper limb.