| Abstract|| |
Aim: To evaluate the role of sediment cytology of biopsy specimen fixatives in early diagnosis of oral neoplasms.
Materials and Methods: Cytological smears were prepared by centrifuging the fixatives in which the biopsy specimens were received. The smears were analyzed and the cytological results were compared with histological diagnosis.
Results: Of 20 lesions studied by sediment cytology, 8 were labeled as benign, 9 as malignant and 3 cases as inconclusive. Final histopathological diagnosis labeled 12 lesions as malignant and 8 lesions as benign. Comparing the cytological diagnosis with histological sections, 17 out of 20 cases were concordant. The overall diagnostic accuracy of 85% was achieved.
Conclusion: Biopsy sediment cytology is a good complimentary method to histopathology in the study of oral biopsy material.
Keywords: Fixative, oral neoplams, sediment cytology
|How to cite this article:|
Chaudhari VV, Dandekar R, Mahajan AM, Prakash N. Sediment cytology in diagnostic evaluation of oral neoplasms. Indian J Dent Res 2014;25:147-9
The scope of cytology in the early diagnosis of neoplastic lesions has markedly increased and routinely used. A new technique called "Sediment cytology" involves the study of smears prepared from sediment of the biopsy specimen fixatives. The fixative in which biopsy is received contains exfoliated cells from the cut surface of biopsy specimens. The sediment from this fixative is used to prepare smears and provides a potentially rich source for cytological material. Sediment cytology is more correctly called as "Biopsy Sediment Cytology" because sediment can be obtained from various other body fluids, whereas here it is obtained from fixatives in which biopsy specimens are received.  It is usually employed for malignant lesions, keeping in mind that the malignant cells are less cohesive and are readily shed in the fixative medium. Analysis of the sediment of the fixative and interpretation of the cytological picture with relevant clinical and radiological data allows diagnosis in a couple of hours.  Although the final diagnosis rests on histopathological study of original biopsy specimen, a preliminary diagnosis provided by sediment cytology could help in timely treatment planning.  Sediment cytology has been successfully evaluated in variety of lesions such as breast and cervix,  esophagus and stomach,  bladder,  lung,  bone lesions, , and ovarian neoplasms. 
|How to cite this URL:|
Chaudhari VV, Dandekar R, Mahajan AM, Prakash N. Sediment cytology in diagnostic evaluation of oral neoplasms. Indian J Dent Res [serial online] 2014 [cited 2020 Feb 21];25:147-9. Available from: http://www.ijdr.in/text.asp?2014/25/2/147/135904
Sediment cytology has a very bright scope as a rapid preliminary diagnostic method. The purpose for evaluation for sediment cytology in oral neoplasms is that, the oral biopsies that are received are usually small in size and fragmented, making the histopathological diagnosis of these specimens difficult. Often the tissue obtained is regarded as insufficient for diagnosis. Furthermore, the accidental loss of such small tissue specimens can occur during processing, in these cases the sediment from the fixative can be analyzed and a comment on provisional diagnosis can be made. Thus, a study was done to evaluate the efficacy of sediment cytology in oral neoplasms.
| Materials and methods|| |
Twenty oral biopsy specimens received in 10% formalin fixative were analyzed for this cytological study. The material required for this study was left over formalin from specimen bottles in which the biopsies were received. The received specimen was then transferred to a container with fresh fixative. The fluid from the original container was centrifuged at 3000 rpm for 5 min. The supernatant was discarded, and the sediment was washed twice in normal saline. The sediment was used to prepare smears on albuminized slides. Albumin coated slides were used as it ensured better adherence of cells. Smears were fixed in 95% ethyl alcohol and then stained by Papanicolau stain and mounted in distrene, plasticiser, xylene. Cytological smears were evaluated and reported as positive or negative for malignancy depending on the cytological criteria. The malignant smears would show increased cellularity, increased nuclear-cytoplasmic ratio, nuclear and cellular pleomorphism, hyperchromatic nuclei whereas the benign looking smears would show less cellularity and no dysplastic features.  The cytological smears were thus labeled as:
The cytological results were compared with histological diagnosis taking the latter as gold standard.
| Results|| |
Most of the smears were adequately cellular especially the malignant lesions. Smears from benign lesions showed less cellularity. In addition to isolated cells, smears often contained a number of microscopic pieces of tissue. The tissue fragments composed of single layer of cells showed tissue morphology clearly, whereas thick tissue fragments obscured the cellular morphology.
The smears that showed features of malignancy such as increased nuclear-cytoplasmic ratio, nuclear hyperchromatism, bizarre mitosis were labeled as malignant, which were histopathologically later confirmed as squamous cell carcinomas [Figure 1] and [Figure 2]. One of the smears showed large, atypical lymphoblasts with dusty chromatin and a peripheral rim of cytoplasm, and was histopathologically diagnosed as non-Hodgkin's lymphoma [Figure 3].
The smears that were labeled benign showed spindle shaped cells with few chronic inflammatory cells which were histopathologically confirmed as fibrous neoplasms [Figure 4]. Smears with large number of chronic inflammatory cells with few normal squamous cells were histopathologically diagnosed as radicular cysts. One of the smears showed large number of red blood cells with scattered inflammatory cells, this could either be extravasated blood from the cut surface of biopsy specimen or could be a vascular neoplasm. The histopathological diagnosis in this case was a capillary hemangioma.
|Figure 1: Papanicolau stained smear shows cluster of epithelial cells with nuclear hyperchromatism, increased nuclear-cytoplasmic ratio, and nuclear pleomophism suggestive of malignancy|
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|Figure 2: Papanicolau stained smear shows cluster of epithelial cells showing dysplastic features suggestive of malignancy|
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|Figure 3: Papanicolau stained smear shows atypical lymphoblasts with dusty chromatin and thin peripheral rim of cytoplasm|
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Of 20 lesions studied by sediment cytology, 9 lesions were labeled as malignant, 8 lesions as benign and 3 as inconclusive, as they were not sufficiently cellular to provide diagnosis. The final histological diagnosis labeled 12 lesions as malignant and 8 as benign as shown in [Table 1]. Out of 12 malignant lesions, there were 11 cases of squamous cell carcinomas and a nonHodgkin's lymphoma. Of 8 benign lesions 3 were inflammatory fibrous hyperplasias, 2 radicular cysts, 1 capillary hemangioma, 1 aggressive fibrous lesion and a fibroma.
|Table 1: Comparing the diagnosis of cytological smears with the histological sections, 17 out of 20 cases were concordant. 3 (15%) of the cases were found to be inconclusive which was quite satisfactory. The overall accuracy in diagnosing benign and malignant oral lesions was 85% |
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| Discussion|| |
This study adopted a new technique in rapid diagnosis of oral neoplasms. It has great significance in diagnosis of bone lesions as a long time is taken in obtaining a routine histopathological report because of the need for decalcification, that is required for these specimens. A rapid preliminary diagnosis can be provided within 1-3 h of specimen receiving.  It has also been significantly studied in rapid diagnosis of ovarian neoplasms where fine needle aspiration cytology is seldom performed. 
Apart from rapidity of diagnosis, the other advantages of this technique is that it is a simple process that does not require any additional armamentarium. Furthermore, the Papanicolau staining technique used is routinely available, long lasting and gives good details of cellular structure as well as of the matrix. Potentially valuable material is used instead of being discarded. Furthermore, it can be used as an adjunct to frozen sections since, in a developing country like ours, where the facility of frozen sections is not available at many centers, this simple and cheap technique can be of much help in rapid diagnosis. 
Of 12 malignant lesions, 9 lesions were correctly diagnosed and 8 out of 8 benign lesions were correctly diagnosed on sediment cytology while 3 cases were inconclusive. Thus, sediment cytology was found to be accurate in diagnosing 17 out of 20 lesions and an overall diagnostic accuracy achieved was 85%. Valiathan et al. studied the role of sediment cytology in bone lesions and got an accuracy of 79%, whereas Nagalotimath et al. achieved a 100% accuracy.  Shahid et al. achieved a diagnostic accuracy of 90.3% in ovarian neoplasms.  Considering the fact, that no such similar study has been performed on oral lesions, our findings were in accordance with above mentioned studies, presenting an overall diagnostic accuracy of 85%, which is quite acceptable. The limitation of the study was that the cytological smears only categorized the lesion as benign or malignant, but a conclusive diagnosis was not possible and a future study with a large sample size is imperative.
| Conclusion|| |
Biopsy sediment cytology is a good compliment to histopathology in the study of oral biopsies. The procedure is simple, inexpensive and rapid and can be utilized with potential benefit in any laboratory for a preliminary diagnosis.
| References|| |
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|3.||Shah S, Rahman K, Siddiqui F, Akhtar K, Zaheer S, Sherwani R. Bone lesions: Role of sediment cytology. Diagn Cytopathol 2009;37:397-401. |
|4.||Gupta RK. Cytologic examination of endoscopic and colonoscopic biopsy supernates. Acta Cytol 1989;33:137-8. |
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Vishakha V Chaudhari
Department of Oral Pathology and Microbiology, MGV'S KBH Dental College and Hospital, Nasik, Maharashtra
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4]