Electromyography and computed tomography scan-guided fine needle aspiration biopsy of discrete extraocular muscle metastases

Discrete or isolated metastasis to the extraocular muscles without an accom panying intraconal or extraconal mass is rare.(1) Although it is estimated that 5% of orbital metastasis involves extraocular muscles only,(2) to our knowledge there are no reports of discrete extraocular muscle involvement f rom renal cell carcinoma. With discrete extraocular muscle involvement, acc urate localization within the infiltrated region of the muscle is of paramo unt importance in achieving a safe and positive biopsy. We describe a case with discrete extraocular muscle metastasis from a renal cell carcinoma, wh ere a novel technique of FNAB (fine needle aspiration biopsy) of the medial rectus was undertaken, with EMG (electromyography) control and CT (compute rized tomography) scan guidance.