Brachial Plexus Injury Secondary to Spontaneous Upper Limb Haematoma.

Spontaneous upper limb muscle haematomas are rare clinical phenomenons, which often go under- or misdiagnosed. They can present management challenges in the context of anticoagulant therapy, especially in the presence of other medical conditions. We present the case of a 52-year-old male with an initially missed presentation of a spontaneous muscle haematoma that progressed and re-presented to the emergency department (ED) with signs of mixed upper limb neuropathy requiring surgical evacuation and an emergency fasciotomy. This case highlights the importance of prompt diagnosis and intervention. While brachial plexus injuries from haematoma compression are uncommon, in our case, we discuss the need for surgical intervention to relieve pressure and optimise patient outcomes when clinically concerned about compartment syndrome or progressive neuropathy.