Abstract:  Objective  To summarize the clinical characteristics of patients with nasal tumors presenting with diplopia as the initial symptom. Design  Retrospective case series. Participants  Fifteen patients presenting with diplopia as the initial symptom and ultimately diagnosed with nasal tumors at the Department of Neurology, Beijing Tongren Hospital, between January 2009 and December 2024. Methods  Clinical symptoms, signs, and imaging features of the 15 patients were retrospectively analyzed. The disease course, case characteristics, and their potential correlations were examined. Main Outcome Measures  Patient gender, age at onset, main clinical symptoms, neuro-ophthalmic examination findings, imaging results, and pathological diagnoses. Results  Among all 15 patients, 11 were male (73.3%), and ages ranged from 26 to 75 years (mean: 50.2±13.5 years). None exhibited nasal symptoms. Abducens nerve involvement was universal. Isolated abducens nerve palsy occurred in 10 patients (66.7%). Other presentations included abducens plus trigeminal nerve palsy (1 case), abducens, trigeminal, and oculomotor nerve palsy (2 cases), abducens palsy combined with trigeminal nerve palsy and Horner syndrome (1 case) and abducens palsy with papilledema (1 case). Pathological types were predominantly nasopharyngeal carcinoma (9 cases, 60%), followed by fibrosarcoma (2 cases), and one case each of adenoid cystic carcinoma, neuroendocrine tumor, Rosai-Dorfman disease, and lymphoma. Among the 10 patients with isolated abducens nerve palsy, 2 had lymph node metastasis and 1 had both lymph node and bone metastasis (metastasis rate: 30%). Of the 4 patients with abducens plus trigeminal nerve palsy, 2 (50%) showed no metastasis. Both patients with additional oculomotor nerve palsy developed metastasis (100%): one had lymph node metastasis, and the other had lymph node, para-aortic lymph node, and bone metastasis. Conclusion  This study showed that nasal tumors presenting with diplopia as the initial symptom were uniformly malignant and lacked significant nasal symptoms. Isolated abducens nerve palsy was the most common sole clinical manifestation. Concurrent involvement of the trigeminal and oculomotor nerves was associated with a high metastasis rate. 

Key words:  Diplopia, Nasal tumor, Abducens nerve palsy, Trigeminal palsy, Oculomotor nerve palsy