Acute Ulnar Neuropathy Caused by a Hemorrhagic Intraneural Ganglion Cyst: Ultrasound as First-Line Imaging?

Introduction

Intraneural ganglion cysts are benign mucinous masses that form within peripheral nerves nearby adjacent joints and can cause neurologic symptoms of diverse intensity. The common peroneal nerve is most frequently affected followed by the ulnar nerve. Due to a better understanding of the pathogenesis and more precise imaging methods, it is now known that intraneural ganglion cysts are not as rare as previously thought. Nevertheless, a uniform consensus regarding diagnostic imaging and optimal surgical therapy of such lesions has not yet been established (Desy et al. J Neurosurg 2016; 125: 615–630).

The pathogenesis of intraneural ganglia is explained by the articular (synovial) theory by Spinner (Spinner RJ et al. J Neurosurg. 2003; 99: 330–343), defining an articular branch as a causative factor for the development of such lesions. The imaging modality that has been preferred for locating the articular branch is MRI. However, in many reported cases, the causative articular branch is simply overlooked by the examiners (Desy et al. J Neurosurg 2016; 125: 615–630).

Intraneural hematomas are, contrary to ganglion cysts, extremely rare with overall around 20 reported cases (De Ruiter et al. World Neurosurg 2015; 84: 1977–1984).

We introduce a case of an acute ulnar neuropathy at the wrist caused by a trauma-induced hemorrhagic ganglion cyst diagnosed by means of sonography.

Publication History

Article published online:
16 March 2021