Abstract
Purpose: :
To describe and illustrate four surgical steps employed during diagnostic transvitreal fine–needle aspiration biopsy of solid intraocular tumors of the posterior segment to maximize the chance of obtaining a satisfactory, representative tumor specimen and simultaneously avoid major complications.
Methods: :
Retrospective descriptive report based on 25–year experience with over 400 fine–needle aspiration biopsies of solid intraocular tumors. Most diagnostic biopsies in our series have been performed via a transvitreal route using indirect ophthalmoscopy for visualization of the needle tip during its transit across the vitreous and into the tumor.
Results: :
The most important technical consideration in diagnostic transvitreal fine–needle aspiration biopsy of solid posterior intraocular tumors is secure fixation of the globe with traction sutures to ensure that it does not rotate during the biopsy. This step helps to avoid unexpected ocular rotation that might result in retinal tearing by the biopsy needle and gross bleeding from the tumor. The second important technical consideration is use of a connector tubing between the biopsy needle and the aspirating syringe during the biopsy. This step ensures that movements of the aspirating syringe during aspiration will not be transmitted directly to the biopsy needle. The third technical step to be emphasized is use of biopsy needles of appropriate size and shape. For most of our biopsies, we have found that a 25–gauge hollow lumen needle provides a reasonable balance between shaft rigidity and sufficient lumen size for aspiration. We bend the needle to an appropriate angle just above its bevel for FNAB of any tumor 3 mm or less in thickness. We then impale the tumor more tangentially to its surface than would be done with a straight needle and a thicker tumor. This step ensures that we do not puncture or perforate the sclera overlying the tumor during the biopsy. Finally, we currently recommend sampling three distinct regions of each tumor to improve our chances of obtaining a representative sample of the lesion and avoiding sampling errors.
Conclusions: :
The several technical steps of transvitreal fine–needle aspiration biopsy we describe and illustrate in this report improve the likelihood of recovery of a sufficient number of representative cells for correct cytodiagnosis and also minimize the risk of major biopsy related complications.
Keywords: pathology: human • pathology techniques • tumors