Surgical treatment of a complex craniocervical malformation combined with posterior cranial fossa teratoma: a case report and literature review

BACKGROUND: Basilar invagination (BI) with atlantoaxial dislocation (AAD) is not uncommon in patients with scoliosis, Klippel-Feil syndrome (KFS), and other bone deformities. Cases with combinations of the abovementioned dislocations and deformities with posterior cranial fossa teratoma are rare in the clinic and difficult to handle. CASE PRESENTATION: This case presents a 34-year-old woman diagnosed with atlantoaxial dislocation and posterior cranial fossa mass. After two surgeries, the posterior cranial teratoma was completely removed with satisfactory atlantoaxial reduction. The postoperative 1-year follow-up examination showed that the bone graft fusion was successful, without remaining significant dysfunction. CONCLUSIONS: The surgical risk of irreducible atlantoaxial dislocation combined with posterior cranial fossa tumor is huge. Thus, it needs to be fully preoperatively evaluated and managed carefully in accordance with sound surgical principles.