Clinicopathological Patterns, Associations, and Management of Orbital Involvement in Sinonasal Malignancies: A Retrospective Study.

Background Sinonasal malignancies are uncommon head and neck tumors that frequently present at an advanced stage due to their deep anatomical location and nonspecific early symptoms. Orbital involvement represents an important indicator of locally aggressive disease and has direct implications for staging and treatment planning. This study was conducted to analyze the clinicopathological profile, radiological patterns of orbital invasion, and management strategies in patients with sinonasal malignancies involving the orbit. Methods A retrospective observational study was carried out in the Department of ENT - Head and Neck Surgery at the Pakistan Institute of Medical Sciences, Islamabad, Pakistan. Patients with histopathologically confirmed sinonasal malignancies and radiological evidence of orbital extension from April 2022 to March 2026 were included. Relevant demographic, histological, staging, orbital invasion patterns, treatment modalities, and discharge outcomes were extracted from hospital records. Data were analyzed using descriptive statistics, and associations were assessed using chi-square and Fisher's exact tests where appropriate. Results A total of 78 patients were included. The mean age was 57.6 ± 12.2 years, and 45 (57.69%) were male. Squamous cell carcinoma was the most common histological subtype (28, 35.90%), followed by adenocarcinoma (18, 23.08%) and sinonasal undifferentiated carcinoma (13, 16.67%). All patients presented with advanced disease, including 16 (20.51%) at stage III and 62 (79.49%) at stage IV. Eye-related clinical features were common, with ocular pain/discomfort in 56 (71.79%), proptosis in 48 (61.54%), and epiphora in 44 (56.41%) patients. A significant difference in mean age was observed across histological subtypes (p = 0.003), while no significant associations were found with gender (p = 0.92), stage (p = 0.41), or pattern of orbital invasion (p = 0.95). The highest level of erosion seen on radiology showed that only lamina papyracea erosion was the most frequent orbital involvement (31, 39.74%), followed by periorbital tissue (18, 23.08%), extraconal fat (13, 16.67%), extraocular muscles (10, 12.82%), and orbital apex (6, 7.69%). Orbit-preserving surgery was performed in 53 (67.95%) patients, while 16 (20.51%) underwent exenteration and 9 (11.54%) received chemoradiotherapy. A significant association was noted between histological subtype and surgical management (p < 0.001), with higher exenteration rates in sinonasal undifferentiated carcinoma and adenoid cystic carcinoma. Conclusion Sinonasal malignancies with orbital involvement most commonly presented at an advanced stage (predominantly stage IV), with squamous cell carcinoma being the most frequent histological subtype and the lamina papyracea being the commonest route of orbital extension. A significant variation in mean age was observed across histological subtypes, whereas no significant association was found between histology and gender, stage, pattern of orbital invasion, or overall treatment modality. However, histological subtype showed a significant association with surgical management, particularly the need for orbital exenteration.