fine needle aspiration brief description

brief summary

1. Fine Needle Aspirate 1

2. INTRODUCTION Procedure to obtain cells and tissue fragments through a needle introduced into abnormal tissue and its study. First introduced in 1930s by Martin, Ellis, and Stewart in US 2

3. Objective: provide the referring physician information on the nature of the sampled tissue in order to focus appropriate diagnostic and therapeutic decisions, all at minimal risk to the patient. Viewed as a coordinated sequence of diagnostic events: Collection of pertinent clinical data Needle sampling of the abnormality Specimen preparation and staining Interpretation Communication and reporting. 3

4. FNAC are employable as initial diagnostic procedure : Cost effectiveness Lower risk than surgical biopsy Readily repeatable Useful for multifocal lesions Minimal physical and psychological discomfort for the patient Rapid reporting Bedside diagnosis of neoplastic , hyperplastic , and inflammatory masses 4

5. Therapeutic procedure for the evacuation of cystic lesions Permits the diagnosis of some benign conditions Renders unnecessary the need for excision biopsy in advanced disease, elderly patients, or in cases where the treatment is non-surgical. A rapid means of confirmation of recurrence of previously treated malignancy without surgery. 5

6. Sensitivity and Specificity of FNA Studies - sensitivity of FNAC in distinguishing benign from malignant salivary tumours varies from 58% to 98%, with specificity usually above 90% . 6 STUDY Seningen et al Specificity( % of cases correctly identified as negative among all cases identified as negative by excisional biopsy in the study) ranged from 81.2% to 100% . Zubaida et al 100 cases of Soft tissue lesions FNAC correlated with H/P examination revealed that the accuracy for benign soft tissue masses -94.38% &malignant soft tissue lesions-100%

7. Equipment/apparatus used during FNA NEEDLES Needle gauge is based on external diameter. Fine needles should be 23 gauge (ext. Diameter 0.6 mm) less (ext. Diameter 0.7 mm). Important to use smaller needles : Is less painful Causes less bleeding Risk of tumour seeding is considerably reduced Thicker needles (G18, ext. diameter 1.2 mm, or wider) carry an ever-increasing risk of complications including significant haemorrhage . 7

8. Syringes and syringe holders The Swedish-designed syringe holder ( Cameco AB, Taby, Sweden) is suitable, although alternatives are now available. 10 ml or a 20 ml sterile disposable plastic syringe can be used, depending on personal preference. 8

9. Slides, fixative and collection fluid Clean slides with frosted ends are required if direct smears are to be prepared at the time an aspirate Direct smears can be either wet-fixed by alcohol spray or immersion in 95% alcohol, or rapidly air-dried. There are two main types of transport media: Fixation fluid that kills organisms and cells, Non-fixative ⁄ culture fluid -keeps the material viable until processing Fixed cell preparations-alcohol-based fixative is satisfactory. Cell blocks are to be prepared-10% buffered formalin is satisfactory. Hank’s physiological saline and sterile normal saline, can also be used 9

10. Local anaesthetic 2% lignocaine is generally sufficient for local anaesthetic . Application of anaesthetic cream at the proposed puncture site is helpful in children and needle-phobic patients. Ethylene spray for skin anaesthesia and needle-free commercial kits for application of local anaesthetic can also be used . 10

11. Methods used in Fine Needle Aspiration Cytology Two methods: I.Suction fnac techniques: The needle is passed into the lesion and negative pressure is applied, usually by virture of a syringe attached to the needle, and often with the help of a syringe holder. Useful when draining a liquid from the lesion ( eg cyst fluid, ascites or pleural fluid) 11

12. II. Capillary method: Without the aid of suction, with a needle alone. The needle is passed into the lesion and multiple fast jabbing movements in and out of the lesion as well as in different directions are performed. Once the material is seen in the hub of the needle, there is usually sufficient materials for collection. 12

13. PROCEDURE I.Technique for Superficial FNA Under Direct Visualization: FNA biopsy is a safe and efficient method of obtaining cells for diagnostic cytologic evaluation of palpable superficial masses from breast, thyroid, salivary glands, lymph nodes, cysts and metastatic tumors, utsing a 20 cc syringe, 22 gauge needle and optional syringe holder. 13

14. II.Technique for Image Guided FNAof Deep Lesions: Non-palpable, deep lesions may be accessed by guiding the 22 gauge needle through a trajectory to its target under the guidance of ultrasound, fluoroscopy or computed tomography. The radiologist uses scans such as CT &/or USG. 14

15. Ultrasound-guided FNA Endoscopic ultrasound guided fNA (EUS-FNA) is a valuable and safe tool to obtain cellular material for cytological examination . US is readily available and provides a rapid, safe and inexpensive means of guiding FNAs and is increasingly used for breast, thyroid and head & neck aspirates 15

16. Computed tomography (CT) guided FNA Lesions less than 1 cm in diameter located deeply within the body can be reached with precision using this technique. 16

17. FNA limitations The limitations: Technical, related to the nature of the lesion itself Intrinsic (theses are limitations that are specific to FNA regardless of technique or lesion type). 17

18. Poor technique can mislead the unwary pathologist into making a false-positive diagnosis. Excessive application of force while spreading the smear can lead to crushing and nuclear distortion and dissociation (Crushing artefacts ), can result in the false impression of hyperchromasia . Delay in fixation of the smear for papanicolaou staining can result in cellular enlargement; comparison with air-dried giemsa stained smears can be helpful in avoiding such false-positive diagnoses. Technical limitations:

19. Limitations related to the lesion itself: some lesions share similar features on FNA and are difficult to differentiate from each other. Certain types of lesions can lead to false-negative diagnoses. Also, it is difficult to aspirate fibrous lesions, and samples are often hypocellular and haemorrhagic . The smears may show only stromal fragments. In a proportion of cases, further investigation with imaging modalities and core biopsies may be necessary 19

20. Intrinsic limitations: cytological appearances of papillary lesions, which range from benign papilloma to invasive papillary carcinoma, can be similar. In addition, benign papillomas can harbour areas of ductal carcinoma in situ. it can sometimes be difficult to distinguish between a mucocele -like lesion and mucinous carcinoma on cytology. Diagnosis is indefinite in some conditions such as follicular adenoma vs. carcinoma of the thyroid, Samples taken may not be representative of the lesion, Difficulty of cytological diagnosis in some conditions e.g. lymphomas 20

21. FNA contrasted with Core Biopsy Both methods have a high degree of sensitivity and specificity. The use of core biopsy has increased, especially in the evaluation of lesions that are associated with high inadequacy rates with FNA cytology . However, core biopsy requires local anaesthesia and may result in more discomfort post-procedure, and its results usually take longer to be obtained. Disposables and equipment required to perform FNA are less expensive than for core biopsy. 21

22. The fundamental indication for FNAC is a lesional mass that is palpable or visible by a radiological imaging method. May also assist in establishing a specific diagnosis for radiolucent lesions of the jaw. Thinning or destruction of cortical bone permits the use of thin needles to aspirate such abnormalities. 22

23. There is a relatively large volume of literature documenting the effectiveness of FNA for diagnosis of head and neck and salivary gland lesions. Scant literature that’s explore the potential of FNA for the diagnosis of intraoral and lesions of the maxillofacial region.

24. STUDY 1 ( Singh S et al) FNA-performed on 50 patients Out of 50 , a definite + ve diagnosis of malignancy or benignancy was given in 45 cases (90%). 21 were proved malignant & 19 were benign on biopsy.5 cases-biopsy n/a 14 cases diagnosed as malignant on FNA were proved malignant on biopsy. 3 cases which were reported suspicious of malignancy were also confirmed on h/p as malignant-overall diagnostic accuracy of 100% for + ve malignant FNA 24

25. 25 CONCLUSION: FNAC is a highly accurate procedure for differentiating benign and malignant lesions. Specific cytological diagnosis may be difficult to make in the absence of characteristic architectural patterns. Diagnosis of aspirates from cystic lesions may be less specific than the solid lesions due to paucity of specific lesional cells in the former and also due to superimposed infection .

26. STUDY 2 ( Sakarwal N et al) 26 A total of 82 cases were studied. Aspiration was performed with 22-23 gauge needle attached to a 20 ml disposable syringe. The needle was introduced into the target suction was applied by retracting the syringe plunger to the 1-2 ml mark. The needle moved back and forth 4-5 times in same plane to ensure minimal bleeding. Aspiration was taken from proliferative or ulcero -proliferative lesions. ,

27. In 28 cases, biopsies were taken, and histopathological diagnosis was given which were then correlated. Correlation of FNAC with Histopathology Reports Most of the benign and malignant lesions reported in FNAC correlated with the h/p results. There was one false positive result in the benign group where aspiration showed SCC, but the h/p showed keratosis only. There was one false negative where fnac showed chronic inflammatory lesion and the h/p report showed SCC

28. Sensitivity The present study which had a high sensitivity of 94.44% Specificity Study showed a specificity of 85.71% CONCLUSION Cytological examination of the oral cavity is an accurate and reliable diagnostic tool in the pre-operative work-up of patients with intraoral lesions. Detailed cytomorphologic examination coupled with clinical data, and appropriate immunocytochemical study can lead to an accurate diagnosis. Although most cases are not problematic, few cases can be challenging to the cytopathologists , especially minor salivary gland masses. 28

29. Study 3 (Gupta N et al) The cases were retrieved from the records of the department of cytology and gynecological pathology in a tertiary care centre in North India. FNAC was performed without radiological guidanceusing a 22–23 G needle and 20 cc disposable syringe, fitted on Cameco’s handle. 157 cases of intraoral/ oropharyngeal lesions could be retrieved. The sites was the palate , tongue, buccal mucosa , floor of the Mouth, tonsil , alveolus, retromolar area &posterior pharyngeal wall three cases 29

30. 30 Diagnostic accuracy in the present series was 87.7% with eight false-negative and one false-positive case. False-negative cases were mainly sampling errors with a single case of interpretation error in salivary gland tumor. Gunhan et al.experienced high accuracy in diagnosing oral cavity and jaw bone lesions by FNAC. Scher et al.had no false-positive diagnosis in malignant lesions. Shah et al. (1999)[11] had a sensitivity of 93.9% and specificity of 85.7% in their study.

31. CONCLUSION Study illustrates the role of FNAC in the diagnosis of a variety of benign as well as malignant lesions of the oral cavity & oropharynx . Deeply situated oral/ oropharyngeal lesions are sometimes difficult to aspirate. FNAC saved over 50% of patients from surgery/excision biopsy in the present study. FNAC is highly accurate for the malignant lesions which can be of great help in early planning of the definitive course of management.

32. Generally, the advantages of FNA cytology are: the possible availability of results within a few hours, few complications and good patient acceptability . In addition, with careful selection of suitable lesions, and when performed and examined by experienced operators and cytologists, FNA cytology is highly specific for the detection of malignant cells.

33. CONCLUSION The FNA remains an indispensible tool in diagnostic Cytopathology despite some of its limitations. Its accuracy, sensitivity or specificity is a function of the technique applied during sample collection and the skill of the Aspirator. constant training of personnel involved in FNA and review of FNA approach may reduce the limitations in using FNA in diagnostic communities. It is technically advantageous to come combine certain procedure such as FNA and Core biopsy or cell block rather than depending on a single procedure.

34. References Singh S, Garg N, Gupta S, Marwah N, Kalra R, Singh V, Sen R. Fine needle aspiration cytology in lesions of oral and maxillofacial region: Diagnostic pitfalls. J Cytol 2011;28:93-7. Sakarwal N, Awasthi S, Dutta S, Nizammudin S, Kumar A, Ahmad F, Vyas P. Fine Needle Aspiration Cytology: A Diagnostic Tool for Oral Lesions. Int J Sci Stud 2015;3(2):90-94. Gupta N, Banik T, Rajwanshi A, Radotra BD, Panda N, Dey P, et al. Fine needle aspiration cytology of oral and oropharyngeal lesions with an emphasis on the diagnostic utility and pitfalls. J Can Res Ther 2012;8:626-9. 34