Abstract
RATIONALE: Orbital metastases are rare, partly because the orbit lacks lymphatic drainage. Metastatic disease initially presenting with isolated ocular symptoms is exceptionally uncommon. We report a case in which ocular manifestations were the first indication of metastatic renal cell carcinoma (RCC). PATIENT CONCERNS: An elderly man with no significant prior medical history presented with ocular distension and pain. He reported no systemic symptoms, such as low back pain or hematuria. DIAGNOSES: Computed tomography and magnetic resonance imaging revealed a well-circumscribed, round orbital mass with moderate enhancement on contrast-enhanced imaging. Preoperative differential diagnoses included hemangioma and schwannoma. Histopathological examination after surgery confirmed orbital metastasis from RCC. Subsequent abdominal computed tomography identified the primary tumor in the left kidney. INTERVENTIONS: Because of the lesion's proximity to the paranasal sinuses, the mass was completely excised through an endoscopic transnasal approach. The right sinus was entered, the lamina papyracea was exposed, and the tumor was removed completely. OUTCOMES: The patient was referred to a comprehensive medical center for further systemic management. At the 1-month follow-up, his ocular symptoms had improved significantly. LESSONS: This case highlights the importance of considering metastatic disease in the differential diagnosis of orbital masses, even in the absence of systemic symptoms. The rarity of orbital metastasis from RCC suggests possible organ-specific metastatic pathways and underscores the need for further investigation into tumor heterogeneity and the molecular mechanisms of site-specific metastasis. Awareness of the diagnostic and management strategies for orbital metastases is clinically important.