Spontaneous and idiopathic chronic spinal epidural hematoma: two case reports and review of the literature

Spinal epidural hematoma (SEH) represents the most frequent entity of acute or chronic spinal bleeding. Based upon pathogenesis, SEH can be classified as idiopathic, spontaneous, and secondary. The idiopathic forms are considered not to be attributed to any specific risk factors. Spontaneous SEH, accounting for 0.3-0.9% of all spinal epidural space occupying lesions, instead is associated with risk factors (such as substantial soft trauma or coagulation abnormalities). The chronic form, as our literature review revealed, is the rarest and its most frequent location is the lumbar spine. The pathophysiology of spontaneous and idiopathic SEH is still under debate: There are only a few reports in literature of chronically evolving SEH with progressively increasing pain and neurological impairment. Magnetic resonance imaging may be inconclusive for differential diagnosis. Here, we present two cases of lumbar chronic SEH with slow, progressive, and persistent lumbar radicular impairment. The first patient reported a minor trauma with slight back contusion and thus was classified as spontaneous SEH. In the second case not even a minor trauma was involved, so we considered it to be idiopathic SEH. In both cases preoperative blood and coagulation tests were normal and we did not find any other or co-factors in the patients' clinical histories. MR imaging showed uncertain spinal canal obstructing lesions at L3 and L4 level in both cases. Surgical treatment allowed a correct diagnosis and resulted in full clinical and neuroradiological recovery after 1 year follow-up. Our aim is to discuss pathogenesis, clinical and radiological features, differential diagnosis and treatment options, on the background of relevant literature review.