Subacute Brachial Plexopathy due to Intraneural Epithelioid Hemangioma: A Case Report.

Brachial plexopathy is a common consideration in the differential diagnosis of upper extremity sensory and motor deficits, and neoplasms signify one possible etiology of brachial plexopathy. Of the neoplastic brachial plexopathies, hemangiomas involving the brachial plexus are rare. Most reported cases describe extraneural brachial plexus hemangiomas that present as a palpable, tender neck mass associated with pain and sensory disturbance, with minimal motor deficits. Here we share the case of a 48 year-old man with intraneural epithelioid hemangioma of the brachial plexus who presented with prominent motor weakness and no palpable mass. The patient presented with subacute onset of left arm pain, numbness and progressive weakness. Neurologic exam revealed lower motor neuron signs and weakness spanning multiple nerve root and peripheral nerve distributions. Dedicated brachial plexus MRI showed two mass lesions involving the cords of the brachial plexus, with corresponding FDG-avidity on PET/CT. Biopsy revealed intraneural atypical epithelioid hemangioma. After nerve transfer surgery, he had moderate improvement in left arm strength. This case serves to: emphasize the importance of both clinical localization and dedicated brachial plexus imaging in the evaluation of brachial plexopathy; introduce to the literature a new clinical presentation of brachial plexus hemangiomas; encourage consideration of neoplastic brachial plexopathy even when faced with an illness script resembling Parsonage-Turner Syndrome, to avoid delays in diagnosis and treatment.