A 19-year-old girl was admitted with a history of difficulty in moving her neck for several years and a sudden onset of neck pain three months before. Plain radiographs of the cervical spine revealed destruction of the left half of the 6th cervical body with an expansive soap-bubble appearance. Neurological examination on admission was within normal limits. The angiography and bone scintigraphy revealed no abnormality. MRI of T1-weighted image showed a cystic lesion with various signal intensities. T2-weighted image demonstrated a hyperintense balloon-like lesion in the vertebral body and left lamina. At surgery, a cystic tumor was fully extirpated by the posterior approach and the bony defect was packed with apatite granules. She was discharged without any neurological deficits. This disease should be considered as one of the etiologies when a patient with difficulty in neck movement is encountered in young generation.