Pancreatic cancer metastasis presenting as an arachnoid cyst of the cervical spine: a case report

Spinal extradural arachnoid cysts are rare expanding lesions, and their etiology is mainly unknown. The authors present a rare case of metastatic pancreatic cancer presenting as an arachnoid cyst of the cervical spine. A 61-year-old woman with progressive neurological deficits was presented with a very large cystic mass from C3 to C6 and C7 and T1 that was a metastatic lesion causing severe collapse of vertebral bodies and subluxation. A posterior laminectomy from C3 to C6 for excision of the cysts and marginal excision including laminectomy around C7 and T1 were performed with instrumented fusion to prevent further collapse and subluxation of T1. No communication between the cysts and the subarachnoid space was found in the surgical field. The neurological symptoms rapidly improved immediately after the surgery. The histology of resected specimens was metastatic mucin-producing adenocarcinoma. This report describes a rare case of metastasis of pancreatic cancer presenting as an arachnoid cyst of the cervical spine. The significance of this study is that metastatic cystic lesions from pancreatic cancer should be considered in the differential diagnosis of arachnoid cysts of the spinal canal.