IgG4-Related Hypertrophic Pachymeningitis: A Great Clinical Imitator

We present a diagnostically challenging case of a 45-year-old woman with a long-standing clinical course characterized by episodic dysphonia, epistaxis, seizures, and cranial neuropathies. Extensive evaluations initially led to a suspected diagnosis of non-Hodgkin lymphoma. However, elevated serum IgG4 levels and histopathological reevaluation confirmed IgG4-related hypertrophic pachymeningitis. The patient responded well to methotrexate and prednisone. This case underscores the importance of considering IgG4-RD in unexplained meningeal syndromes and highlights the need for timely recognition to avoid invasive interventions.