Computed tomographic localization for fine needle aspiration biopsy of orbital tumors.

Fine needle aspiration biopsy techniques have recently been applied to the evaluation of orbital masses. Ultrasound and CT examination have been useful in accurately localizing and characterizing such lesions prior to biopsy. Small retrobulbar tumors may be difficult to biopsy using blind needling, despite accurate localization. Preliminary studies on cadaver orbits confirmed that successful biopsy of the normal optic nerve could be accomplished using direct CT guidance. The technique was applied to 2 patients with monocular blindness due to small infiltrating optic nerve tumors and a histologic diagnosis was obtained in each case. This low morbidity procedure though applicable to only a small group of patients may spare them the morbidity of an orbitiotomy or craniotomy.