Abstract
Purpose :
Vitreous cytology is typically requested when diagnostic vitrectomies are performed to exclude vitreoretinal lymphoma. We describe a method for routine cytological assessment of therapeutic vitrectomies.
Methods :
Undiluted vitreous and vitreous washings from patients undergoing therapeutic pars plana vitrectomy (PPV) for indications including retinal detachment, macular hole, vitreous haemorrhage and epiretinal membrane were placed separately in RPMI at 1:1 dilution, kept at 4oC and transported to the cytology laboratory within 1 to 12h. Cytospin preparations were stained with Papanicolaou, Giemsa and Alcian Blue/PAS according to published methods.
Results :
Cytospin preparations of undiluted vitreous and washings showed similar cellularity and cytomorphologic preservation, negating the need to separately submit undiluted vitreous in this clinical setting. A delay of up to 12 hours between collection and processing did not affect specimen quality when RPMI was used. The AB/PAS was useful for highlighting inner limiting membrane and lens capsule (PAS positive) and the hyaluronic acid component of vitreous (AB positive). Excellent cytomorphological preservation was achieved with this protocol, allowing the identification of inner limiting membrane, epiretinal membrane and its constituent cell types, pseudoexfoliation material, retinal fragments, reactive macrophages/hyalocytes, other immune cells, lens capsule and asteroid hyalosis. CD3, CD20, CD68 and GFAP immunohistochemistry was performed in selected cases; however the lack of control slides is a potential limitation of this method.
Conclusions :
We describe a reliable method for cytomorphological assessment of therapeutic vitrectomies. The use of RPMI allows a delay of up to 12h between collection and processing, making this a user friendly protocol that can be readily incorporated into clinical and laboratory workflows. Routine cytological assessment of vitreous from therapeutic PPV confers the following advantages: (i) ‘tissue’ diagnosis for clinicopathological correlation; (ii) tissue auditing for surgical risk management; (iii) maintaining a laboratory skill set essential for the diagnosis of vitreoretinal lymphoma; (iv) characterisation of vitreous constituents in a range of non-neoplastic pathologies for research and potential prognostic purposes; and (v) diagnosing unsuspected pathology.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.