Early Recurrence of a Solid Variant of Aneurysmal Bone Cyst in a Young Child After Resection: Technique and Literature Review and Two-year Follow-up After Corpectomy.

Aneurysmal bone cysts (ABCs) are considered to be rare benign tumors that may affect long bones or the vertebral column. Their incidence varies and is reported to be 1.4% of all benign skeletal tumors. The solid-variant aneurysmal bone cyst (S-ABC) is even rarer and constitutes 3.5% to 7% of all vertebral ABCs. We report the case of an Enneking stage 3 S-ABC in a 5-year-old boy at C7 that showed rapid local recurrence after primary excision from posterior and dorsal stabilization requiring ventral corpectomy and posterior excision of the right lateral mass and right posterolateral fusion. Histologic examination disclosed an S-ABC. To our knowledge, this is the first case of S-ABC described in the literature that used both anterior and posterior approaches and complete corpectomy. Over a 2-year period, the patient showed no radiologic or clinical signs of local recurrence with excellent neurologic function. Solid-variant aneurysmal bone cysts are difficult to diagnose and treat, and careful clinical and radiologic assessment should be done to tailor an appropriate surgical plan to prevent recurrence and neurologic sequelae. To the best of our knowledge, there are to date no publications that studied the behavior of this subtype.