Schwannoma of the brachial plexus: a rare cause of monoparesis.

To cite: Patel ML, Sachan R, Seth G, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2012-008525 DESCRIPTION Schwannomas, also referred as neurilemmomas, are benign, encapsulated perineural tumour of neuroectdermal derivative that originate from the schwan cells of the neural sheath of motor and sensory peripheral nerves. About 25% of schwannomas occur in the head and neck region, usually involving cranial nerves and sympathetic chain; however, brachial plexus schwannomas are uncommon, occurring in 0.3–0.4/100 000 person per year. Their malignant potential is low, they can be locally destructive if allowed to progress. Primary tumours of the brachial plexus are unusual. Patients commonly seek medical attention