Primary Brachial Plexus Tumor

Case Contributor: Gopalaratnam Balachandra, M.D.

Editor: Rathachai Kaewlai, M.D.

Coronal T1W and T2W MR images of the brachial plexus show a fusiform-shaped mass (large arrows) along the course of the right cervical nerve root (small arrow). The mass demonstrates heterogeneous low T1 and high T2 signal intensity. It has smooth, well circumscribed borders.

Axial T1W post contrast MR image shows heterogeneous enhancement of the mass (arrows) with a central area of non-enhancement.

Facts: Primary Brachial Plexus Tumor

• Rare tumor, most commonly benign with good prognosis after surgical resection
• Clinical presentations: pain, paresthesia, palpable mass
• Common pathology: schwannoma, neurofibroma. Other possibilities: malignant peripheral nerve sheath tumor (MPNST), desmoid, ganglion, epidermoid

Imaging

• MRI is the study of choice to delineate the margins of tumor from surrounding tissues
• Characteristic feature on any imaging techniques is close relationship with the parent nerve, which helps to exclude other possibilities such as lymphadenopathy, vascular anomalies, etc.
• Low signal on T1, high signal on T2 and heterogeneous enhancement
• MRI cannot differentiate schwannoma from neurofibroma

This case - Schwannoma of the brachial plexus in a 32-year-old woman who presented with pain in the right arm and right neck mass.

References:

1. Binder DK, Smith JS, Barbaro NM. Primary brachial plexus tumors: imaging, surgical, and pathological findings in 25 patients. Neurosurg Focus 2004;16.

2. Rettenbacher T, Sogner P, Springer P, et al. Schwannoma of the brachial plexus: cross-sectional imaging diagnosis using CT, sonography, and MR imaging. Eur Radiol 2003;13:1872-1875.

About Case Contributor: Dr. Balachandra is the head of the Department of Radiology at Government General Hospital in Pondicherry, S. India.