Hypertrophic pachymeningitis during radiotherapy for locally advancedprostate cancer: A coincidental or causal relationship

Abstract

Hypertrophic pachymeningitis (HP) is a rare clinical disorder characterized by focal or diffuse thickening of the dura mater with various neurological manifestations. It is known to be associated with autoimmune diseases, infections, and neoplasms. However, a review of the literature did not reveal that HP occurs during radiotherapy for cancer. In this report, we present a rare case of HP during radiotherapy for cancer in a 71-year-old male patient with high-risk prostate cancer who developed a headache and abducens nerve palsy during radiotherapy following androgen deprivation therapy. Magnetic resonance imaging (MRI) revealed dura mater thickening without brain metastases. The cerebrospinal fluid analysis demonstrated elevated protein levels. The patient was diagnosed with HP and treated with oral prednisolone. Within 2 days of treatment, the headache subsided, and the abducens nerve palsy resolved completely after 6 months of radiotherapy. In view of these events, we suggested a possible correlation between radiotherapy and HP, particularly, if meningitis develops during radiotherapy in the absence of infection or cancer seeding.