Introduction: Outline main difficulties in preoperative diagnosis of non-typical sequestered disc fragments to posterior epidural (PSDH) region without connection to intervertebral disc leading to MRI misdiagnosis.

Case report: We present a patient with a three months history of lumbar pain, sciatica and neurological deficit with preoperative diagnosis of meningioma based on MRI features. We include a review of isolated cases dealing with this rare entity. We describe the case of a 64-year-old man with severe lumbar pain of acute onset, left sciatica and progressive knee weakness for 3 months. MRI showed a large calcified and longitudinal dural lesion from midline to dorsal left radicular foramen at L3-L4, with no relation to disc space, suggesting a lumbar meningioma or other neurogenic tumour. During surgery a non-vascularized, strongly attached to dural lesion was found, and en bloc resection was achieved. Histological examination revealed herniated disc tissue. Patient experienced almost full recovery. PSDH are extremely rare (less than 0.1%), usually in younger patients, with no typical presentation, except for months of history and motor deficits, which are all non-specific peculiarities. However, the longitudinal appearance of PSDH on MRI and contrast studies may help in its preoperative diagnosis, which due to neurological deficits requires prompt treatment.

Discussion: Certain characteristics on contrast MRI allow a preoperative diagnosis of PSDH. However, due to the extremely rare frequency of this problem, the absence of typical symptoms/signs, and their common appearance as extradural spinal tumors, preoperative diagnosis remains a challenge that in most cases is solved at surgery.