2025 Poster Presentations
P166: SKULL BASE INFLAMMATION: DIAGNOSTIC AND THERAPEUTIC CHALLENGES WITH AN EMPHASIS ON RADIOLOGIC MANIFESTATIONS.
Daniel Wang, MD; Ann Jay, MD; Rashmi Thakkar, MD; Medstar Georgetown University Hospital
Background: Skull base inflammation is a complex clinical entity with multifactorial etiologies, ranging from infectious to neoplastic processes. Many of these processes present with overlapping clinical and radiologic findings, which combined with complex skull base anatomy can pose diagnostic and therapeutic challenges. We aim to highlight the radiologic manifestations of various etiologies of skull base inflammation and provide recommendations for an approach to diagnosis and management.
Methods: Retrospective case review of patients diagnosed with skull base inflammation based on initial imaging was performed. Advanced imaging modalities were utilized to assess the extent, distribution, and characteristics of inflammatory changes. Clinical correlation and follow-up data were incorporated to evaluate the accuracy and utility of radiologic findings. Two illustrative cases of the case series are presented below.
Case 1: A 75-year-old male with a history of type 2 diabetes presents with worsening headache, neck pain, right sided hearing loss, and nasal congestion for two months. Pertinent labs include fever to 39.5 degrees, elevated CRP and ESR, and borderline leukocytosis. Brain MRI demonstrates soft tissue thickening and enhancement on the nasopharynx and retropharyngeal space, with inflammatory changes extending into the deep spaces of the neck with small abscess formation just below the skull base. Destructive changes with abnormal marrow signal to the clivus were seen. Imaging findings were most consistent with nasopharyngeal cellulitis with adjacent skull base osteomyelitis. Subsequent biopsy of the nasopharynx showed benign squamous mucosa with aggregates of acute and chronic inflammatory changes. Unfortunately, the patient was started on empiric antibiotics on admission, thus cultures were negative. The patient was continued on broad spectrum IV antibiotics with improvement.
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Case 2: A 75-year-old male who presents with headache, hoarseness, and left sided hearing loss. Nasal endoscopy showed subtle fullness of the left nasopharyngeal mucosa without obvious tumor. Biopsy was performed showing nonspecific lymphocytic aggregates, for which the differential included lymphoproliferative disorder or reactive process. Subsequent brain and neck MRI demonstrates an ill-defined infiltrative left nasopharyngeal mass with encasement of the left internal carotid artery and adjacent infiltrative changes to the clivus. Additional testing of the initial biopsy samples showed aggregates of lymphoid tissue most consistent with marginal b-cell lymphoma.
Discussion: Initial clinical presentation in both cases were similar, with both presenting with headaches and hearing related symptoms. Important clinical distinguishers were the presence of fever and elevated inflammatory markers in case 1. MRI appearances were also similar, with both cases demonstrating soft tissue thickening and enhancement in the nasopharynx with associated infiltrative osseous changes. In acute skull base inflammation, prompt biopsy and culture are essential to rule out an underlying malignancy and in the case of infection, a specific organism to direct specific antibiotic treatment.
Conclusion: The clinical and imaging findings of patients with skull base inflammation is often nonspecific, but there are methods to help narrow the differential as detailed above. Biopsy with histopathology and cultures are essential to tailor antibiotic coverage and rule out underlying malignancy.