Aseptic hypertrophic pachymeningitis in a patient with Rheumatoid Arthritis - a case of involvement of the central nervous system by the disease?

Hypertrophic pachymeningitis (HP) is a rare clinical entity which uncommonly occurs in rheumatoid arthritis (RA) patients. We describe the case of a rheumatoid factor and anti-citrullinated protein antibody positive RA male that was diagnosed with HP and multiple mononeuropathy. Although histological evaluation was not performed, after excluding infectious and neoplastic causes, it was possible to determine a probable inflammatory etiology. He was treated with glucocorticoids and rituximab with a good clinical evolution. This case represented a challenging differential diagnosis but the need for an accurate diagnosis should not delay the introduction of an effective therapy for a potentially lethal disease.