Idiopathic cranial pachymeningoencephalitis focally affecting the parietal dura mater and adjacent brain parenchyma: case report.

OBJECTIVE AND

IMPORTANCE

Cranial pachymeningitis is a typically diffuse granulomatous disease, which often affects the tentorium and falx. We report a rare case of idiopathic cranial pachymeningoencephalitis focally affecting only the left parietal dura mater and adjacent inferior parietal lobule.

CLINICAL PRESENTATION: A 46-year-old woman, with no history of disease, suddenly had a generalized convulsion. A gadolinium-enhanced T1-weighted magnetic resonance image showed homogeneously stained meninges extending to the cortical parenchyma with marked perifocal edema. The thickened dura was visualized as a hypointense area on a T2-weighted magnetic resonance image.

INTERVENTION: The patient underwent successful en bloc excision of the mass involving the dura mater and adjacent brain parenchyma. Histological examination of the dura mater revealed large numbers of chronic and acute inflammatory cells. These cells were also present in the subarachnoid and Virchow-Robin spaces and part of the brain parenchyma in the resected cortex. After the operation, the patient experienced no neurological deficits or recurrent mass for 10 months.

CONCLUSION

Early diagnosis of pachymeningitis using magnetic resonance imaging is important for the treatment of pachymeningoencephalitis, because diffuse involvement of the dura mater and brain parenchyma can make en bloc excision difficult.