Complex Regional Pain Syndrome Caused by an Axillary Lipoma

Abstract

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy syndrome, is a rare chronic neuro-inflammatory pain condition, which can follow a soft-tissue, bone (type I), or nerve injury (type II) that can be severe and often lasts longer than the original tissue damage. Lipomas impinging on the brachial plexus are rare. To date, there have been no documented cases of CRPS caused by a benign tumor. Here, we report a rare case of CRPS caused by surgical removal of a left axillary lipoma impinging on the brachial plexus. The patient presented with neuropathic pain and hyperalgesia of the left arm, in a non-dermatomal pattern, and pain out of proportion to touch and painful stimulus. Persistent CRPS continued to occur post-operatively for one year without significant change in her pain characteristics. CRPS following elective or emergent surgery to the extremities can pose significant complications to recovery and post-operative care. This condition can be induced through surgery or trauma, which can complicate recovery, impair motor functionality, and cause debilitating pain. Treatment modalities and pathogenesis for CRPS remain obscure and limited, which leads to wide misdiagnosis. Our case highlights the importance of considering CRPS when evaluating differential diagnoses for pre- and post-operative conditions affecting the upper and lower extremities.

Keywords: brachial plexus; complex regional pain syndrome; lipoma; reflex sympathetic dystrophy; surgery.

Figure 1. Left brachial plexus region

Red arrow indicates the location of the axillary lipoma prior to operation.

Figure 2. Operative Image

Image showing intraoperative neurophysiological monitoring with stimulation probe during surgery. Red arrow shows the location of the axillary lipoma after removal.

Figure 3. Excised left axillary lipoma

Axillary lipoma measuring 7.3 x 5.9 x 1.5cm excised in one piece.