Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 8 5 2024 03 13 198 202 Bhavna Arora Pt Bhagwat Dayal Sharma Post Graduate Institute of Medical Sciences, Rohtak, Haryana, India Vineet Mishra Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India 2023 05 03 2023 06 11 Chronic idiopathic hypertrophic pachymeningitis (IHP) is a rare inflammatory entity with unknown etiopathogenesis, resulting in dural thickening and fibrosis. This mimics the illuminated night view of the Eiffel tower on contrast-enhanced MRI. The authors report a characteristic MRI sign of chronic IHP on contrast-enhanced MRI. The authors present a case of a 30-year-old male presenting with a headache for the past 3 years with recent aggravation of symptoms. Laboratory and imaging results were reviewed. Follow-up imaging with ongoing treatment was also reviewed. The etiology could not be determined even after extensive investigations. Contrast-enhanced MRI revealed diffuse enhancing thickening of the pachymeninges along the posterior cerebral hemispheres, falx cerebri, and tentorium cerebelli, giving the typical ‘Night view of the Eiffel tower’ appearance on coronal images. There was cerebral venous sinus thrombosis secondary to IHP. The patient was treated with corticosteroids and anticoagulants. The follow-up scan revealed reduced thickness and enhancement of the meninges. https://crcp.tums.ac.ir/index.php/crcp/article/view/821