Spontaneous Regression of a Retroodontoid Transverse Ligament Cyst: A Case Report.

Abstract

Transverse ligament cysts (TLC) are rare, surgically complex lesions arising posterior to the odontoid process of C2. Direct compression of the cervicomedullary junction is a devastating consequence of untreated lesions. We report the first case of spontaneous TLC regression without surgical intervention. A 75-yr-old woman presented to an outside hospital with acute episodes of left face and upper extremity numbness. Magnetic resonance imaging (MRI) demonstrated a well-circumscribed 5.8 mm cystic mass at the atlantoaxial junction, posterior to the odontoid process, most consistent with a TLC. She presented to our institution 1 yr later with symptoms of progressive occipital neuralgia seeking surgical treatment. No evidence of cervical myelopathy was identified on clinical examination. Repeat MRI showed near doubling of the cyst, with no brainstem edema. The patient elected for surveillance of the cyst with a transforaminal steroid injection at C1-C2 for her occipital neuralgia. One year later, symptoms of occipital neuralgia had resolved and she remained neurologically intact; MRI of the cervical spine showed near complete involution of the cyst. Symptomatic TLCs are often managed with surgical decompression and, in selected cases, fusion with good functional outcome. However, these interventions carry high risk of postoperative morbidity, particularly in the elderly. Conservative surveillance is rarely reported as a viable option. We present the first case of spontaneous TLC regression in the absence surgery or neck bracing. In select patients without acute myelopathy, clinical and radiographic surveillance may be considered for the management of TLCs.