Idiopathic hypertrophic cranial pachymeningitis: case report with 7 years of imaging follow-up

Abstract

Idiopathic hypertrophic cranial pachymeningitis is a rare inflammatory disease with diffused involvement of the dura. Often, the definite diagnosis is made immediately with biopsy and the involved dura is removed surgically. Consequently, extensive preoperative imaging studies usually are not available. We reviewed a case of idiopathic hypertrophic cranial pachymeningitis and collectively summarized the interesting features from the 7 years preceding surgical treatment. These chronologic imaging findings with progressive intracranial involvement included dural thickening, dural mass, sinus thrombosis, and venous congestion constituted comprehensive pictures of idiopathic hypertrophic cranial pachymeningitis. The thickened dura may also at times mimic dural masses, such as en plaque meningioma.

Fig 1.

Contrast-enhanced CT scans show increased enhancement at the right cavernous sinus. A, Contrast-enhanced CT scan obtained in 1994 shows that the right tentorium is thickened with homogeneous enhancement due to an inflammatory reaction of the pachymeninges. B, Contrast-enhanced CT scan obtained at a more caudal level shows that involvement of the right cavernous sinus correlates with the patient’s symptom of optic neuropathy.

Fig 2.

MR images obtained in 1995 show the thickened right tentorium. No significant progression of tentorium thickening or cavernous sinus enhancement is noted. A, Thickened right tentorium is hypertense on axial T1-weighted image. B, Thickened right tentorium is hypertense on coronal T1-weighted image. C, Thickened right tentorium is hypointense on coronal T2-weighted image.

Fig 3.

MR images show mild increasing thickness and enhancement of the left tentorium. A, Axial T1-weighted contrast-enhanced MR image obtained in May of 1998, at the onset of blindness in the right eye and decreased left visual acuity, shows increased right cavernous sinus enhancement and more diffuse involvement of the tentorium bilaterally and of the posterior falx. Prominent dura enhancement can also be seen at the prepontine area, with mild compression of the brain stem. B, Coronal T1-weighted contrast-enhanced MR image shows a focus of nodular dural enhancement at left temporal area, with minimal perifocal edema.

Fig 4.

Coronal T1-weighted contrast-enhanced MR image obtained in June of 1998 shows regression of dural enhancement and the left temporal nodular mass with minimal dural thickening and edema.

Fig 5.

Coronal T1-weighted contrast-enhanced MR image obtained in January of 1999 at the onset of right hearing impairment shows increased enhancement of the right mastoid area, although decrease in the tentorium and falx enhancement can be seen.

Fig 6.

Coronal T1-weighted contrast-enhanced MR image obtained in December of 1999 shows increased intensity of the left mastoid at the onset of left hearing impairment.

Fig 7.

In July of 2001, the patient suffered from delirium and confusion. CT scan and MR image show enhanced dural mass at the left temporal area, with perifocal edema. A, Contrast-enhanced CT scan shows an irregularly enhanced left temporal mass, with compression of the left temporal horn. B, Coronal T1-weighted contrast-enhanced MR image shows an enhanced dural-based mass of the left tentorium, with an edematous change of the left temporal lobe. The mass is located in the same area as that revealed in Figure 3B.

Fig 8.

Cerebral angiogram of the left internal carotid artery shows nonopacification of the straight sinus.

Fig 9.

Narrowed straight sinus, which correlates with dural sinus thrombosis, was noted on MR venograms. A, Sagittal MR venogram shows nonopacification of the straight sinus and indicates thrombosis. B, Coronal view.

Fig 10.

Pathology slide of the meningeal tissue from a left temporal craniotomy shows inflammatory cells with lymphoplasmacytic infiltration, foamy histiocytes, and vascular proliferation (hematoxylin and eosin; original magnification, ×150).