Supplementary Material for: Reactive orbital myositis as a first manifestation of renal cell carcinoma

We present the case of an 81-year-old male with orbital myositis (OM) as the first manifestation of metastatic renal cell carcinoma. The patient, with a history of age-related macular degeneration, presented with pain and limited eye movement in his left eye. A computed tomography (CT) scan revealed an osteolytic lesion in the left sphenoid that caused a reactive myositis. Further investigations uncovered a left renal mass with pulmonary and skeletal metastases. A core needle biopsy confirmed the diagnosis of renal carcinoma, and palliative treatment was provided. Despite interventions, the patient passed away six months after the debut of his symptoms. This case highlights the rare presentation of OM caused by metastatic renal carcinoma, underscoring the importance of thorough evaluation in atypical ocular symptoms