Spontaneous chronic epidural hematoma of the lumbar spine mimicking an extradural spine tumour.

Purpose: Spontaneous chronic epidural hematomas are extremely rare and can be extremely challenging to diagnose and differentiate. The clinical findings, computed tomographic scan and magnetic resonance imaging does not always enough to complete differentiate this condition. Our purpose is to report a case of a spontaneous chronic epidural hematoma presenting as an extradural mass leading to compressive radicular symptoms with images of bony scalloping which are sparsely reported in the literature.

Methods: We describe a 61-year-old woman who was evaluated after 18-month history of pain, disestesias and mild weakness in both lower extremities with significant radicular symptoms on the right side associated to neurogenic claudication.

Results: CT scans revealed a nodular image of soft tissue density located in the right anterolateral epidural space at the L4-L5 level demonstrating resorption of the bony margins. MRI studies revealed a round mass in the vertebral canal displacing the dural sac and scalloping the posterior wall of the L4 vertebral body. Diagnosis was established between a degenerative cyst versus an atypical neurinoma. Surgical findings demonstrated an isolated well-formed chronic hematoma.

Conclusion: Spontaneous chronic epidural hematomas are rare, even more when they produce scalloping of bony structures becoming a diagnostic challenge. Therefore they should be always considered as a differential diagnosis in patients with extradural chronic compressions taking into account that also chronic epidural hematomas can cause bone involvement.