Idiopathic Hypertrophic Spinal Pachymeningitis with an Osteolytic Lesion

Abstract

Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a chronic, progressive, inflammatory disorder characterized by marked fibrosis of the spinal dura mater with unknown etiology. According to the location of the lesion, it might induce neurologic deficits by compression of spinal cord and nerve root. A 58-year old female with a 3-year history of progressive weakness in both lower extremities was referred to our institute. Spinal computed tomography (CT) scan showed an osteolytic lesion involving base of the C6 spinous process with adjacent epidural mass. Magnetic resonance imaging (MRI) revealed an epidural mass involving dorsal aspect of cervical spinal canal from C5 to C7 level, with low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. We decided to undertake surgical exploration. At the operation field, there was yellow colored, thickened fibrous tissue over the dura mater. The lesion was removed totally, and decompression of spinal cord was achieved. Symptoms improved partially after the operation. Histopathologically, fibrotic pachymeninges with scanty inflammatory cells was revealed, which was compatible with diagnosis of idiopathic hypertrophic pachymeningitis. Six months after operation, motor power grade of both lower extremities was normal on physical examination. However, the patient still complained of mild weakness in the right lower extremity. Although the nature of IHSP is generally indolent, decompressive surgery should be considered for the patient with definite or progressive neurologic symptoms in order to prevent further deterioration. In addition, IHSP can present as an osteolytic lesion. Differential diagnosis with neoplastic disease, including giant cell tumor, is important.

Hypertrophic pachymeningitis in a southern Chinese population: a retrospective study

“…If conservative treatments are ineffective, surgery for decompression should be considered, especially for HSP [61][62][63][64]. Decompressive surgery, such as laminectomy or laminoplasty, and excision of the thickened dura were recommended [60,65,66].…”

A case report of atypical long segmental thoracic hypertrophic pachymeningitis with ossification of ligamentum flavum and literature review

“…Homogeneous enhancement pattern has been reported frequently in IHP [21][22][23]. A case of IHP with non-enhancement in MRI was also reported [24]. Similarly, in this case, contrast MRI presented low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images.…”

“…Similarly, in this case, contrast MRI presented low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. This kind of enhancement pattern is considered to be associated with the lack of inflammatory reaction in pathological dura matter tissue [20,24,25]. Moreover, in some previously reported cases of HP, hyperostosis [26,27] or destruction [24,28] of adjacent bone tissue was observed.…”

Idiopathic Hypertrophic Pachymeningitis in the Craniocervical Junction

“…Hypertrophic pachymeningitis (HP) is a rare disease, and it is characterized by chronic progressive inflammatory fibrosis and thickening of the dura mater with resultant compression of the spinal cord or brain 11 18) . Although accessibility and imaging techniques including magnetic resonance (MR) imaging have improved recently, it can be missed or it can go unrecognized because of its indolent and non-specific symptoms 5) . Syphilis, tuberculous infection, fungal infection, and autoimmune disorders such as rheumatoid arthritis or Wegener's granulomatosis can be the possible causes 5 7 11 18) .…”

“…Although accessibility and imaging techniques including magnetic resonance (MR) imaging have improved recently, it can be missed or it can go unrecognized because of its indolent and non-specific symptoms 5) . Syphilis, tuberculous infection, fungal infection, and autoimmune disorders such as rheumatoid arthritis or Wegener's granulomatosis can be the possible causes 5 7 11 18) . However, the majority of cases have no identifiable causes and are called idiopathic HP (IHP) 11) .…”