Journal of Cytology

ORIGINAL ARTICLE
Year
: 2014  |  Volume : 31  |  Issue : 2  |  Page : 83--86

Comparative study of manual liquid-based cytology (MLBC) technique and direct smear technique (conventional) on fine-needle cytology/fine-needle aspiration cytology samples


Prajkta Suresh Pawar, Rasika Uday Gadkari, Sunil Y Swami, Anil R Joshi 
 Department of Pathology, S. R. T. R. M. C. Ambajagai, Beed, Maharashtra, India

Correspondence Address:
Prajkta Suresh Pawar
C/o Nilesh Gaddewar, Flat No. 411, Honey Archana Complex, Untakhana Road, Nagpur - 440 009, Maharashtra
India

Abstract

Background: Liquid-based cytology technique enables cells to be suspended in a liquid medium and spread in a monolayer, making better morphological assessment. Automated techniques have been widely used, but limited due to cost and availability. Aim: The aim was to establish manual liquid-based cytology (MLBC) technique on fine-needle aspiration cytology (FNAC) material and compare its results with conventional technique. Materials and Methods: In this study, we examined cells trapped in needles hub used for the collection of FNAC samples. 50 cases were examined by the MLBC technique and compared with the conventional FNAC technique. By centrifugation, sediment was obtained and imprint was taken on defined area. Papanicolaou (Pap) and May-Grünwald Giemsa (MGG) staining was done. Direct smears and MLBC smears were compared for cellularity, background, cellular preservation, and nuclear preservation. Slides were diagnosed independently by two cytologists with more than 5 years«SQ» experience. Standard error of proportion was used for statistical analysis. Results: Cellularity was low in MLBC as compared with conventional smears, which is expected as remnant material in the needle hub was used. Nuclei overlap to a lesser extent and hemorrhage and necrosis was reduced, so cell morphology can be better studied in the MLBC technique. P value obtained was <0.05. Conclusion: This MLBC technique gives results comparable to the conventional technique with better morphology. In a set up where aspirators are learners, this technique will ensure adequacy due to remnant in needle hub getting processed



How to cite this article:
Pawar PS, Gadkari RU, Swami SY, Joshi AR. Comparative study of manual liquid-based cytology (MLBC) technique and direct smear technique (conventional) on fine-needle cytology/fine-needle aspiration cytology samples.J Cytol 2014;31:83-86


How to cite this URL:
Pawar PS, Gadkari RU, Swami SY, Joshi AR. Comparative study of manual liquid-based cytology (MLBC) technique and direct smear technique (conventional) on fine-needle cytology/fine-needle aspiration cytology samples. J Cytol [serial online] 2014 [cited 2022 May 26 ];31:83-86
Available from: https://www.jcytol.org/text.asp?2014/31/2/83/138669


Full Text

 Introduction



Liquid-based cytology

Liquid-based cytology is a technique that enables cells to be suspended in liquid medium and spread in monolayer and thus better morphological assessment is possible. It includes the preparation and evaluation of cells collected in a liquid fixative. It is being introduced in developed countries to improve the sensitivity of the Pap test. [1] Liquid-based preparations are increasingly being used both for gynecologic (gyn) and nongynecologic (nongyn) cytology, including fine-needle aspirations. [2] Two technologies-ThinPrep (Hologic, Marlborough, MA, U.S.A.) and BD SurePath (BD Diagnostics-TriPath, Burlington, NC, U.S.A.) have been more widely used. [1]

The advantages of liquid-based cytology include improved sensitivity and specificity since fixation is better and nuclear details are well-preserved. Abnormal cells are not obscured or diluted by other epithelial or inflammatory cells. There is, therefore, a lower rate of unsatisfactory cervical cytology samples. The residual cell suspension can be used to make further cytological preparations or used for other tests like detection of human papilloma virus DNA. Other ancillary techniques like immunocytochemistry can also be performed on the residual sample. [1],[3]

The more widely used technologies for liquid-based cytology require expensive equipment. [1]

The aims and objectives of the study were to prepare cytology smears using the manual method of liquid-based cytology on material remaining in the needle hub and syringes after fine-needle cytology (FNC)/fine-needle aspiration cytology (FNAC), [4] observe morphological features, compare results of direct smear examination with manual liquid-based smears and correlate with histopathological findings in those cases in which a biopsy was also done.

 Materials and Methods



Patients attending cytology outpatient department for FNC/FNAC in a rural tertiary health care center were selected for study. All cases where definitive diagnosis can be made on conventional technique were included in the study, while cases where material was inadequate for diagnosis by either method were excluded from the study. Fifty cases were enrolled in this study approved by the Ethics Committee of the Institute. In this study, we used needle hub material because using entire material would necessitate second prick. This being first study for the establishment of the technique; for ethical reasons second prick was avoided.

Informed consent from all cases was taken. Conventional FNC/FNAC of the patients was carried out. One smear was wet fixed in 95% ethyl alcohol and Pap stained. Air dried smear was kept for May-Grünwald Giemsa (MGG) staining. Material remaining in the needle hub and the syringe was processed immediately for manual liquid-based cytology (MLBC) technique. Whenever, there was delay, samples were preserved at 4°C and processed subsequently for MLBC technique. For this purpose, we prepared the tubes in which molten paraffin wax was added at the base. Over the flat surface of the wax filter paper equal to the size of the bore of the tube was inserted carefully. The needles were removed from the syringes after the smears were made by the conventional method. 2 mL of phosphate buffer at the pH 7.4 was then aspirated into the syringe and the needle was attached to the syringe. The phosphate buffer was then expelled through the needle forcing the cells to be released with the buffer. Glacial acetic acid was added to the hemorrhagic aspirate. Our final tubes contained paraffin wax at the base, filter paper and material obtained in phosphate buffer at the top [Figure 1]. The tubes were centrifuged for about 8 min at 1200 rpm and the supernatant removed. Paper was withdrawn carefully from the tube and imprint was taken on a slide. Wet fixed smears were Pap stained. Air dried smears were MGG stained [Figure 2].{Figure 1}{Figure 2}

Standardization of the method

Various variables studied were, speed of centrifugation -tried 800, 1000, 1200, and 1500 rpm, and finally set at 1200 rpm. Time-samples centrifuged for 8, 10, and 12 min and finally set at 8 min. Tube - tried conical tubes, small size tubes and finally, selected the present tubes. Addition of fixative with albumenized slides was tried but it gave pinkish background so it was not used.

Parameters studied

Conventional smears and MLBC smears were compared under the heading of cellularity, background, cellular preservation and nuclear preservation.

Slides were diagnosed and parameters to be studied were graded independently by two cytologists with more than 5 years' experience. Final diagnosis on both slides was given. Analysis of 50 cases was done. Standard error of the proportion was used for background study analysis. Histopathological correlation was done wherever possible.

 Results



In our study, 50 cases were studied. All cases were having same diagnosis on conventional technique and MLBC technique. Histopathological correlation was done in 14 cases [Table 1]. Cellularity was low in (MLBC) as compared with conventional smears as we are using only material remained in the needle hub, but nuclei overlap to the lesser extent, so better cell morphology can be studied in the MLBC technique [Figure 3]. For background study, we applied standard error of proportion statistics to the data obtained. [5] In MLBC technique hemorrhage and necrosis was reduced as compared with the conventional technique, P value was obtained <0.05, which is highly significant [Figure 4], [Figure 5] and [Table 2]. Myxoid stroma, colloid and mucin was retained [Table 2].{Figure 3}{Figure 4}{Figure 5}{Table 1}{Table 2}

 Discussion



This study was conducted in a resource poor setting in a setup where FNAC is done by residents who rotate every 6 months. This is true for large number of hospitals attached to medical colleges. In this case, diagnostically important material remains in the needle hub and is wasted. This study fulfilled various needs in this scenario. There are no ethical issues in this study as the cellular material remaining in needle hub was used as an adjunct to routinely processed material. The patients in our setting are often diagnosed with advanced stage of disease, for example, caseating lymph nodes, large necrotic metastasizing malignancies. However, even in necrotic inflammatory or hemorrhagic smears malignancy can be underdiagnosed as demonstrated by early findings of RODEO study team. [6] Liquid based cytology is gaining popularity in non gynec FNAC, due to advantages of a cleaner background and reproducibility, better cellular morphology and ability to gain sample for ancillary techniques. [7] Compared to cell block MLBC technique has the advantage of viewing cell morphology comparable to conventional smear without presence of necrosis, hemorrhage. In thyroid FNAC study Saleh et al. [8] found ThinPrep (liquid-based cytology [LBC]) preparation superior to cell block technique to detect atypical/neoplastic thyroid lesions. We have attempted this manual technique considering limitations of our setup. All materials used in this technique are readily available in a modest pathology laboratory and the technique can be easily mastered. We can use better quality filter papers if available. In resource poor settings MLBC is viable approved alternative to automated LBC techniques. [9]

This method was found to retain diagnostically important material such as myxoid stroma, colloid, mucin and a larger study is needed to assess diagnostic accuracy and limitations in specific organs. Though this is the first study using this technique, other MLBC protocols have been tried successfully. Kavatkar et al. [1] found MLBC as cost-effective alternative to automated methods. Godwin et al. [4] studied MLBC on needle hub remaining material in breast malignancy cases and found it diagnostically useful. Alves et al. [10] compared manual and automated methods of liquid-based cytology and found MLBC as effective as in preserving cellular details as automated techniques. The choice of method will depend on price, availability and procedures involved. Maksem et al. [11] found manual method makes liquid-based cytology inexpensive and does not require specialized preparative devices.

 Conclusion



This simple technique using centrifugation, sediment cytology Preparation and layering due to flat surface on paraffin wax can be used as an adjunct in necrotic or large masses or as a diagnostic method after larger studies.

 Acknowledgment



To all teacher staff, technical staff, and PG colleagues who helped us in work.

References

1Kavatkar AN, Nagwanshi CA, Dabak SM. Study of a manual method of liquid-based cervical cytology. Indian J Pathol Microbiol 2008;51:190-4.
2Hoda RS. Non-gynecologic cytology on liquid-based preparations: A morphologic review of facts and artifacts. Diagn Cytopathol 2007;35:621-34.
3Ronco G, Cuzick J, Pierotti P, Cariaggi MP, Dalla Palma P, Naldoni C, et al. Accuracy of liquid based versus conventional cytology: Overall results of new technologies for cervical cancer screening: Randomised controlled trial. BMJ 2007;335:28.
4Godwin A, Iyiola S, Bankole J, Osiagwu D, Muhammad A. Liquid based cytology of cell remnants in needles used for breast fine needle aspiration. J Cancer Ther 2010;1:192-4.
5Altman DG, Bland JM. Interaction revisited: The difference between two estimates. BMJ 2003;326:219.
6Fregnani JH, Scapulatempo C, Haikel RL Jr, Saccheto T, Campacci N, Mauad EC, et al. Could alarmingly high rates of negative diagnoses in remote rural areas be minimized with liquid-based cytology? Preliminary results from the RODEO Study Team. Acta Cytol 2013;57:69-74.
7Veneti S, Daskalopoulou D, Zervoudis S, Papasotiriou E, Ioannidou-Mouzaka L. Liquid-based cytology in breast fine needle aspiration. Comparison with the conventional smear. Acta Cytol 2003;47:188-92.
8Saleh HA, Hammoud J, Zakaria R, Khan AZ. Comparison of Thin-Prep and cell block preparation for the evaluation of Thyroid epithelial lesions on fine needle aspiration biopsy. Cytojournal 2008;5:3.
9Nandini NM, Nandish SM, Pallavi P, Akshatha SK, Chandrashekhar AP, Anjali S, et al. Manual liquid based cytology in primary screening for cervical cancer - a cost effective preposition for scarce resource settings. Asian Pac J Cancer Prev 2012;13:3645-51.
10Alves VA, Bibbo M, Schmitt FC, Milanezi F, Longatto Filho A. Comparison of manual and automated methods of liquid-based cytology. A morphologic study. Acta Cytol 2004;48:187-93.
11Maksem JA, Finnemore M, Belsheim BL, Roose EB, Makkapati SR, Eatwell L, et al. Manual method for liquid-based cytology: A demonstration using 1,000 gynecological cytologies collected directly to vial and prepared by a smear-slide technique. Diagn Cytopathol 2001;25:334-8.