Rare posterior mediastinal hemangiomas invading the spinal cord through the intervertebral foramen and causing acute symptoms: illustrative case.

backgroundHemangioma is a rare vascular tumor characterized by endothelial cell proliferation that primarily occurs in soft tissues. While most cases in the paraspinal posterior mediastinum are clinically indolent, they can also exhibit aggressive growth, leading to severe clinical outcomes and necessitating urgent treatment. OBSERVATIONS: A 61-year-old right-handed female presented with reduced lower-extremity mobility that had begun 4 days earlier. An examination revealed that both lower limbs had grade 4 muscle strength. Computed tomography and magnetic resonance imaging revealed a right T1-3 paravertebral dumbbell-shaped soft tissue mass invading the spinal canal, destroying the T2 vertebra, and compressing the spinal cord and nerve roots. Elective surgery was planned, but a rapid muscle strength decline prompted emergency surgery. Postoperative muscle strength improved to grade 4, and at the 3-month follow-up, muscle strength had fully recovered. LESSONS: Postoperative pathological examination revealed that the mediastinal dumbbell-shaped lesion was a hemangioma. While most hemangiomas progress slowly, acute symptoms of spinal cord compression are exceedingly rare. This case demonstrates the aggressive behavior of hemangioma, which invaded through the intervertebral foramen and compressed the spinal cord, resulting in acute symptoms. This case also shows that surgical removal of the tumor and restoration of spine stability via a posterior approach has proven beneficial. https://thejns.org/doi/10.3171/CASE24485.