A Purely Cystic Giant Sacral Schwannoma Mimicking a Bone Cyst: A Case Report

Abstract

Approximately 1--5% of the spinal schwannomas arise in the sacrum and frequently grow to a considerable size before becoming symptomatic; hence, the term “giant sacral schwannoma” refers to tumors extending into the vertebral body and the extraspinal space (1). Most schwannomas are solid or heterogeneous solid tumors, but they can rarely undergo cystic degeneration, xanthomatous change, or hemorrhage (2). A completely cystic appearance with only thin peripheral wall enhancement is extremely rare. A few cases of solitary cystic schwannomas arising from the spine have been previously reported (3-8). To the best of our knowledge, there is only one previous reported case of a giant solitary cystic schwannoma of the sacrum. Here, we describe a rare case of a totally cystic giant sacral schwannoma presenting as lumbar back pain. Institutional review board approval was obtained.