Spinal Cord Müllerian-Like Cyst at the T12 Vertebral Level: A Case Report and Literature Review.

Müllerian cysts are rare developmental anomalies, typically found in the pelvis, with extrapelvic occurrences reported but spinal cord involvement being exceedingly rare. We present the first reported case of a Müllerian-like cyst located on the surface of the spinal cord at the T12 vertebral level. A 49-year-old woman presented with low back and right leg pain, including electric shock-like sensations during sneezing. Physical examination revealed sensory deficits in the right L5 dermatome, and MRI demonstrated an intradural extramedullary cystic lesion at T12, appearing isointense to cerebrospinal fluid on all sequences, with a subtle surface irregularity. A T12 recapping T-saw laminoplasty was performed for surgical excision, and a subtle surface defect on the spinal cord was identified intraoperatively. Pathological examination confirmed the diagnosis of a Müllerian-like cyst. This case highlights the importance of considering Müllerian-like cysts in the differential diagnosis of intradural spinal cysts, even at unusual locations, and demonstrates that careful review of imaging findings, including subtle surface irregularities, can aid in accurate diagnosis and surgical planning. Complete surgical resection is the treatment of choice, and the prognosis is generally excellent.