Pre-operatively, the lesion was thought to be facet or ligamentous hypertrophy accounting for the appearance of the CT and MRI scans.

The patient was taken to theater for L4/5 decompression and laminectomy. Intra-operatively, the mass in question appeared to be black and friable, there was no material that was consistent with bone. The initial concern was for a tumor and samples were sent intra-operatively for microbiology and histology. The rest of the surgery was uncomplicated. Histology was returned as consistent appearances of a hematoma. 

The patient made an uneventful recovery, their neurological symptoms resolved post-operatively and they were discharged from clinic 6 months post-operatively. 

There was nil prior history of trauma that the patient disclosed. There was no personal or familial history of bleeding disorders that the patient was aware of. It was noted that an episode of sudden onset sciatica since 6 months that the patient had received a corticosteroid facet joint corticosteroid injection. It is hypothesized that this caused a post-procedural bleed which resulted in the hematoma that caused the patient's symptoms of temporary urinary incontinence, a left foot drop and altered left L5 dermatomal sensation.