Idiopathic hypertrophic cranial pachymeningitis: Three biopsy-proven cases including one case with abdominal pseudotumor and review of the literature.

Hypertrophic pachymeningitis (HP) is a rare disorder of diverse etiology. It presents with headaches, cranial neuropathies and ataxia occurring alone or in combination. Dural biopsy is essential to exclude secondary causes of pachymeningitis. There is paucity of data on biopsied cases of HP. We report three biopsy-proven cases of idiopathic hypertrophic cranial pachymeningitis. All our patients had headaches and multiple cranial neuropathies; ataxia was seen in one patient. One patient had recurrent anterior and posterior cranial neuropathies, while one each had recurrent anterior and posterior cranial neuropathies. Two patients had profound irreversible mono-ocular visual loss. All of them showed prominent pachymeningeal thickening on imaging. Infarcts were seen in one patient, which have rarely been documented. All patients showed biopsy evidence of meningeal thickening and nonspecific chronic inflammation of the dura. The disease may have a remitting and relapsing course, and usually responds to steroids. Clinical improvement was excellent in two patients and modest in one on steroid therapy. All our patients required azathioprine during the course of therapy. Early institution and long-term maintenance of steroid therapy prevents neurologic sequelae. Occurrence of abdominal inflammatory pseudotumor in a patient of HP possibly as part of multifocal fibrosclerosis has not been described earlier.