Painful Subacute Cubital Tunnel Syndrome Because of an Intra-Cubital Tunnel Ganglion Cyst: A Case Report

Background: Entrapment of the ulnar nerve in the cubital tunnel occurs as the second most common compression neuropathy of the upper limb. Although the usual etiology is idiopathic or following cubitus valgus, a compressing mass can be a rare cause and should be considered in atypical presentation. Case Report: A 45-year-old male patient presented with subacute onset of cubital tunnel syndrome that progressed rapidly and was associated with significant pain. An intra-canal ganglion cyst was found during surgical decompression of the ulnar nerve. Conclusion: Diagnosis of intra-cubital canal mass should be considered when sudden onset and rapid progression of the cubital tunnel syndrome and dramatic pain coincide. Imaging modalities like ultrasound or magnetic resonance imaging (MRI) may be helpful to reach the correct diagnosis before the surgery.