The pitfalls of differential diagnosis of lumbar spine epidural lesions--exemplification with two particular cases and a review of the literature.

BACKGROUND AND STUDY AIMS: Lumbar spinal epidural lesions could belong to a wide spectrum of pathologies. However, some cases present with rare conditions that can cause significant neurological deficit and raise serious diagnostic challenges. We present two such cases where the clinical picture and the imaging findings failed to elucidate the actual diagnosis, which came as an intraoperative and pathological surprise.

PATIENTS: The first case is that of a 78-years-old male that presented for low back pain, bilateral S1 radicular sciatica, paraparesis, and difficulty walking. The neurologic exam showed the absence of the rotulian reflexes bilaterally, and a partial sensory loss in the crural dermatomes. The MRI showed an epidural mass, contrast enhancing at the L1-L2 level, suggestive for an extraxial tumor. The second case is that of a 62-year-old woman that presented for a hyperalgic sciatica involving the right S1 root with parestesias in the corresponding dermatome. MRI showed a cystic, contrast enhancing lesion in the L5-S1 recess, mimicking a cystic neuroma. Both patients underwent surgery and histopathological exams were performed from the excised pieces.

RESULTS

In the first case the surgery resulted in complete removal of the pathological process and histopathological result returned chronic organized hematoma, concordant with the intraoperatory aspect. The evolution was good. In the second case the histopathological result came back as pulpous disk. Again the evolution was good with complete neurological recovery.

CONCLUSION

In the presence of an epidural mass with clear clinical symptomatology, rare entities like chronic epidural hematoma or posterior migrated disk material should be always considered as a differential diagnosis in patients with suspicion of extradural chronic compressions. In these cases, only the intraoperatory and histopathological exams can provide a clear diagnosis.