Hypertrophic cranial pachymeningitis involving the pituitary gland: A case report

As the use of magnetic resonance imaging (MRI) has become widespread, the reported cases of pachymeningitis have increased. Various inflammations are known to occur in the pituitary gland. However, an association between pachymeningitis and pituitary inflammation has not been recognized previously. This 56-year-old woman complained of incessant headache and deafness. MRI showed thickened dura at the right convexity and a dumbbell shaped pituitary enlargement, which was isointense to the gray matter (T1-weighted images) and homogeneously enhanced. Microscopic examination of the dura mater showed a marked increase of collagen fibers and various inflammatory cells. The anterior pituitary lobe was infiltrated with lymphocytes, and normal tissues were displaced by increased collagen fibers. Hypertrophic cranial pachymeningitis, a rare clinical entity, is a progressive lesion prone to include the dura mater at the skull base and can be fatal. We report a case of hypertrophic cranial pachymeningitis involving the pituitary gland, and discuss the possible etiology of the association.