Delayed Diagnosis of a Large Parietal Meningioma Presenting as Progressive Proprioceptive Loss: A Case Report and Review of Diagnostic Bias Across Specialties.

Meningiomas are common intracranial tumors, but their slowly progressive and atypical presentations are frequently mistaken for peripheral neurologic, musculoskeletal, or ocular conditions. We describe a 60-year-old left-handed man who developed several months of progressive right-sided gait imbalance, proprioceptive deficits, intermittent binocular visual blurring, and late cognitive changes. Evaluations by podiatry, chiropractic care, physical therapy, and optometry initially failed to uncover the cause. Brain MRI eventually revealed a large left posterior parietal dural-based mass with classic meningioma features, marked vasogenic edema, mass effect, and midline shift. Gross-total resection confirmed a WHO grade 1 meningioma (Ki-67 index 15 %). This case emphasizes an atypical presentation with progressive unilateral gait dysfunction accompanied by proprioceptive loss, pyramidal signs, visual symptoms, or cognitive decline. Refractory treatments should prompt early neuroimaging, even after negative peripheral workups. It also highlights how specialty-specific anchoring bias can delay recognition of central nervous system lesions.