Use of impression cytology for the detection of unsuspected ocular surface squamous neoplasia cells in pterygia

Abstract

Purpose: To evaluate the agreement between the methodologies of impression cytology (IC) and histopathology regarding epithelial lesions clinically diagnosed as pterygium and also regarding the detection of unsuspected and associated ocular surface squamous neoplasia (OSSN). Methods: Thirty-two Brazilian patients were included and IC was performed on all pterygia before excision. Histopathogical examination was considered the gold standard and was performed by two experienced ocular pathologists in which consensus existed regarding pterygia diagnosis. IC accuracy was assessed by sensitivity and specificity with a 95% confidence interval. Results: From the 32 primary lesions studied, histopathological examination confirmed the diagnosis of pterygium without atypical cells in 19 cases (60%) and showed unsuspected and associated OSSN cells in 13 cases (40%). IC demonstrated one false-negative and one false-positive result for atypia. Statistical analysis showed an estimated sensitivity of 92%, specificity of 94%, positive predictive value of 92%, and negative predictive value of 94%. Conclusion: IC demonstrated high agreement with histopathological analysis in the detection of atypical epithelial cells in unsuspected OSSN in Brazilian pterygia patients.

Impression cytology as diagnostic tool in horses with and without ocular surface disease

“…ICS and CBS provided samples with equal cell quality in healthy and diseased horses. In human ophthalmology, ICS is used for the diagnosis of ocular surface tumours as cells harvested with ICS are of highest quality [4,9,10,25]. In the current study, the 2 cases of SCC were identified with both ICS and CBS.…”

“…ICS collects the most superficial layers of the ocular surface due to the adhering property of the sampling device [4]. ICS is now widely used in human ophthalmology to examine the healthy ocular surface [5] and to assess conjunctival and corneal alterations in contact lens wearers [6][7][8] Examination of eyes with ocular surface neoplasia [9,10] and keratoconjunctivitis sicca [11,12] are other indications for ICS. A major advantage of ICS is the arrangement of harvested cells in their natural layout; thus enabling clinical pathologists to examine an exact copy of the area of interest.…”

Impression cytology in the evaluation of ocular surface tumors: review article

“…Thus, the question of using IC for the detection of OSSN in the setting of concomitant ocular surface disease requires further studies. Recently, Barros et al reported that IC demonstrated high agreement with the results of the histopathological analysis for detecting atypical epithelial cells from unsuspected OSSN in cases of pterygia from Brazil, showing unsuspected and associated OSSN cells in 13 specimens (40%) (41) . IC presents great advantages: (1) it provides a source of intact and well-preserved epithelial cells from the ocular surface in any type of ocular surface pathology; (2) it is a nonsurgical, easy-to-perform, quick, and inexpensive technique that can always be performed on an outpatient basis; (3) only topical anesthesia is required, and no side effects or contraindications have ever been noted and thus it can be applied to children; (4) repeated IC sampling in the same patient over time is an excellent way to demonstrate changes due to a certain event, to monitor the progress of a disease, or to follow the effect of a therapeutic intervention; (5) IC maintains cell-to-cell contacts, preventing the problems of EC or brush cytology, which may destroy much of the cell morphology, cause overlapping of cells, and hamper clear visualization of the in vivo arrangement of the cells; (6) IC samples can be processed using any type of microscopy in addition to polymerase chain reaction (PCR), immunoblotting analyses, and/or flow cytometry.…”

“…IC presents great advantages: (1) it provides a source of intact and well-preserved epithelial cells from the ocular surface in any type of ocular surface pathology; (2) it is a nonsurgical, easy-to-perform, quick, and inexpensive technique that can always be performed on an outpatient basis; (3) only topical anesthesia is required, and no side effects or contraindications have ever been noted and thus it can be applied to children; (4) repeated IC sampling in the same patient over time is an excellent way to demonstrate changes due to a certain event, to monitor the progress of a disease, or to follow the effect of a therapeutic intervention; (5) IC maintains cell-to-cell contacts, preventing the problems of EC or brush cytology, which may destroy much of the cell morphology, cause overlapping of cells, and hamper clear visualization of the in vivo arrangement of the cells; (6) IC samples can be processed using any type of microscopy in addition to polymerase chain reaction (PCR), immunoblotting analyses, and/or flow cytometry. Based on all these advantages, IC has become the technique of choice for sampling ocular surface epithelium for being a very useful research tool in both basic and clinical aspects (41)(42) . …”

Histopathological Study of Primary Pterygium

“…McKelvie et al [5] have reported elastosis in 100% of their specimens, while a previous Brazilian study found elastosis in 81.4% [16]. In comparison, Tabrizi reported elastosis in 50% of the cases [17], whereas, Barros et al [18], observed elastosis in all pterygia.…”