Background Gradenigo syndrome is an uncommon complication of otitis media, first described by Giuseppe Gradenigo in 1904. The infection spreads from the middle ear to the petrous apex of the temporal bone, irritating cranial nerves V and VI. It classically presents with a triad: otorrhea, abducens palsy, and facial pain in the V1/V2 distribution. Although less common today due to antibiotics, diagnosis and management remain challenging, particularly when caused by atypical etiologies such as neoplasms. We present a rare case of Gradenigo syndrome secondary to a meningioma in a 78-year-old female, emphasizing the importance of considering neoplastic causes and utilizing neuroimaging in patients with progressive cranial neuropathies and a history of brain tumors. Case Presentation A 78-year-old female with a history of four meningiomas and immune thrombocytopenic purpura (ITP) presented with generalized weakness, 3-4 months of painless diplopia, and significant unintentional weight loss. Neurologic exam revealed bilateral lateral gaze palsies, left proptosis, suspected CN III/IV/VI palsies on the left, right CN VI palsy, and mild left facial droop. She also had left-sided hemiplegia from a prior stroke. Rinne test was positive on the right, negative on the left; Weber test was normal. Labs showed hemoglobin of 9.4, platelets 51,000 (rising to 78,000), and ESR of 120 mm/hr. Head CT showed no acute findings. MRI revealed a 3.7 cm enhancing lesion at the left cavernous sinus involving the dura, prepontine cistern, and sella, consistent with a meningioma compressing the pons. Another lesion at the petrous temporal bone was compressing cranial nerves. Neurosurgery was consulted, and outpatient follow-up was advised.

Discussion This case illustrates a rare instance of Gradenigo syndrome mimicking infectious petrositis but caused by a skull base meningioma. Persistence of symptoms despite antibiotics and absence of infection signs pointed to a structural lesion. Although the full triad was not present, many cases are incomplete. Accurate diagnosis requires maintaining a broad differential and early neuroimaging. Without it, tumors may be mistaken for infection, delaying care. Other mimics include skull base infections, thrombosis, coagulopathies, Lemierre’s syndrome, and neoplasms. While antibiotics are standard for infectious cases, mass lesions often require surgery, thus, early recognition of atypical causes is critical to prevent lasting deficits. Even benign meningiomas can present deceptively at the skull base, warranting timely imaging.