[A case of hypertrophic cranial pachcymeningitis in a patient with lymphocytic hypophysitis].

We report a 67-year-old man of lymphocytic hypophysitis complicated by hypertrophic cranial pachcymeningitis. The hypophysitis presenting with central diabetes insipidus caused isolated adrenocorticotropic hormone (ACTH) deficiency after three years and two months since the onset of his illness. Moreover he suffered from left cavernous sinus syndrome after four years. Brain gadolinium (Gd) enhanced MRI, which was obtained in 2001, showed only enhancement of the pituitary stalk. However, brain Gd enhanced MRI, performed four years later, showed not only a remarkable thickening and enhancement of the pituitary stalk but also abnormal enhancement of the lesion in the left cavernous sinus. In addition, it showed diffuse thickening and enhancement of the dura mater. This clinical course suggested that chronic inflammation of the pituitary had spread to the dura mater, a clinical condition differing from parasellar chronic inflammatory disease (PSCID). In addition, because diffuse thickening and enhancement of the dura mater was present, it was likely that lymphocytic hypophysitis was complicated by hypertrophic cranial pachcymeningitis due to autoimmune reactions. We should carefully observe cases of lymphocytic hypophysitis and assess change over time in the dura mater of the whole brain by Gd enhanced MRI.