Case report: Clinical highlights and radiological classification of IgG4-related spinal pachymeningitis: A rare case series and updated review of the literature

Abstract

Purpose: Hypertrophic pachymeningitis associated with immunoglobulin G4-related disease (IgG4-RD) has been rarely reported, and there is little information and no clear consensus on the management of IgG4-related spinal pachymeningitis (IgG4-RSP). The present study described its possible clinical features, including the symptoms, imaging, treatment and prognosis of patients with IgG4-RSP.

Methods: We report three patients who presented with progressive neurological dysfunction due to spinal cord compression. Relevant articles were searched from the PubMed, Web of Science, and Embase databases, and the resulting literature was reviewed.

Results: The literature review provided a summary of 45 available cases, which included three cases from our center. Progressive worsening of neurological impairment was observed in 22 patients (48.9%). The lesions involved the thoracic spine (n=28, 62.2%), cervical spine (n=26, 57.8%), lumbar spine (n=9, 20.0%), and sacral spine (n=1, 2.2%). Furthermore, the lesions were located in the dura mater (n=18, 40.0%), epidural space (n=17, 37.8%), intradural-extramedullary space (n=9, 20.0%), and intramedullary space (n=1, 2.2%). On magnetic resonance imaging (MRI), the lesions generally appeared as striated, fusiform, or less often lobulated oval changes, with homogeneous (n=17,44.7%) and dorsal (n=15,39.5%) patterns being the most common. Thirty-five patients had homogeneous T1 gadolinium enhancement. Early surgical decompression, corticosteroid treatment, and steroid-sparing agents offered significant therapeutic advantages. A good therapeutic response to disease recurrence was observed with the medication.

Conclusion: The number of reported cases of IgG4-RSP remains limited, and patients often have progressive worsening of their neurological symptoms. The features of masses identified on the MRI should be considered. The prognosis was better with decompression surgery combined with immunosuppressive therapy. Long-term corticosteroid treatment and steroid-sparing agent maintenance therapy should be ensured. A systemic examination is recommended to identify the presence of other pathologies.

Keywords: American Spinal Injury Association (ASIA); immunoglobulin G4 (IgG4); immunoglobulin G4-related disease (IgG4-RD); immunoglobulin G4-related hypertrophic pachymeningitis (IgG4-RHP); immunoglobulin G4-related spinal pachymeningitis (IgG4-RSP); magnetic resonance imaging (MRI); spinal compression.

Figure 1

Preoperative thoracic MRI. (A) The sagittal T2WI revealed the homogeneous anterior-posterior spinal cord compression at the T9-T11 level, with a hypointense signal. One to two segments of the head and tail of the lesion presented cavitary changes in the spinal cord. The axial T2WI (corresponding to the white line in A) revealed the ventral and dorsal thickening of the dura, with a hypointense signal. (B) The sagittal T1WI presents the hypointense signal (arrow).

Figure 2

(A) The thickened dorsal dura presenting a band-like shape and rubbery texture (approximately 5.0 cm in diameter). (B) View of the surgical site after the complete resection of the thickened dorsal dura.

Figure 3

(A) A rubbery lesion resembling fish meat. (B) On histopathological examination, the dural mass and surrounding soft tissues presented with chronic and acute inflammation, inflammatory granulomatous micro-abscesses, and a few granulomas. Fibrous tissue hyperplasia, calcification, and a large number of plasma cells were present. The immunohistochemistry revealed the large-scale infiltration of IgG4-positive plasma cells.

Figure 4

Preoperative cervical MRI. (A) The sagittal T2WI revealed a slightly hyperintense signal (arrow). (B) The sagittal T1WI revealed a hypointense signal (arrow).

Figure 5

Flowchart for the literature search for IgG4-RSP.

Figure 6

This illustrates a mass accumulating outside the dura. The mass may be classified as ventral, dorsal, or homogeneous (accumulation on the ventral and dorsal sides), depending on the location of the mass relative to the spinal cord in a right sagittal plane.

Figure 7

When mass grew on the ventral side, this tended to be thicker, and compressed the spinal cord more severely, when compared to the mass on the dorsal side.