2026 Poster Presentations
P009: SINONASAL DISEASE IN PROTEUS SYNDROME: A CASE REPORT AND REVIEW OF THE LITERATURE
George B Sankar, MD1; Nicholas Chapman, BA2; Neal R Godse, MD1; Andrew S Venteicher, MD, PhD2; 1Department of Otolaryngology-Head & Neck Surgery, University of Minnesota Medical School; 2Department of Neurosurgery, University of Minnesota Medical School
Introduction: Proteus syndrome (PS) is a rare disorder driven by a somatic activating mutation of the AKT1 gene, which encodes a serine/threonine kinase central to the PI3K/AKT signaling pathway. PS is characterized by a multi-organ mosaic overgrowth disorder, involving asymmetric overgrowth of connective tissue, bone, skin, and internal organs. As such, PS has a highly variable presentation, including increased risk for tumors, particularly meningiomas. Meningiomas in this context tend to be unilateral, reflecting the mosaic distribution of the AKT1 mutation. Notably, the co-occurrence of meningiomas with sinonasal pathology in PS has not been described in the literature.
Clinical Case: 62-year-old male with a history of PS, including left-sided multifocal meningiomas status post multiple resections followed by radiosurgery in the 2000s for recurrence, who presented to our rhinology clinic with nasal obstruction in the setting of a left-sided sinonasal lesion seen on imaging (Figures 1-2). Based on the patient’s imaging, the decision was made to proceed to the operating room for endoscopic endonasal resection of an anterior cranial fossa extradural skull base lesion. Final pathology revealed benign nasal polyps without obvious spread of meningioma into the nasal cavity. Unfortunately, in the interim the patient has since deceased.
Discussion: PS is a particularly rare disorder with fewer than 200 confirmed cases reported in the literature. While unilateral meningiomas are among the most common neoplastic processes seen in patients with PS, their frequency and character are poorly understood. Furthermore, there is a lack of literature exploring sinonasal disease in patients with PS. There is a limited body of data to suggest that dysregulation in AKT1-regulated pathways may play a role in the development of nasal polyps in patients with chronic rhinosinusitis. Indeed, if both disease processes are driven by activating mutations in the AKT1 gene or its downstream pathways, one would expect nasal polyps to be commonly seen in PS. However, there is no known literature demonstrating such a relationship. Notably, our patient’s significant polyp burden was on the ipsilateral side of the patient’s multifocal meningiomas, including a skull base meningioma. This presentation raises the question of whether the sinonasal disease may have been driven by chronic inflammation in response to a skull base meningioma or potentially related to the AKT1 dysregulation. While meningiomas are recognized neoplastic manifestations of PS, the simultaneous occurrence of sinonasal polyps has not been previously reported, posing an important consideration regarding the relationship between AKT1-driven disease, chronic mucosal inflammation in response to skull base meningiomas, and sinonasal disease in PS. Our case report is not without limitations, including limited literature exploring such a rare disease. Additionally, our tissue sample was not analyzed for AKT1 gene mutations.
Conclusion: There is a paucity of literature exploring the relationship between PS and sinonasal disease, particularly in the setting of a skull base meningioma.
Figure 1: Coronal T1 MRPAGE
Figure 2: Sagittal T1 MRPAGE
Figure 3: Axial T1 MRPAGE