Radiologically guided fnac

Radiologically guided fnac

1. Radiologically guided FNAC:Techniques,advantage and pitfalls Dr.Sonali Timaniya

2. Introduction Cytology is a useful tool to screen and diagnose various pathological lesions in the body without causing significant trauma to the patient.

3. Cytopathology Methods Exfoliative cytology Abrasive cytology Fine needle aspiration cytology

4. Exfoliative cytology Spontaneously shed cells in body fluids Urine CSF Sputum Effusions in body cavities (pleura, pericardium, peritoneum)

5. Abrasive cytology Dislodges cells from body surfaces Imprint Scraping Endoscopic brushing of mucosal surfaces Washing ( lavage ) of mucosal or serosal surfaces Swab

6. Fine Needle Aspiration Cytology FNAC is widely used for deep seated lesions of the body. This helps avoid open biopsy or laproscopic surgery in many situations. Superficial nodules and organs easily targeted Deep organs –radiological guidance is needed

7. Indications of image guided deep seated lesions To diagnose the character & type of primary lesion To assess non palpable and deep seated lesion To know the staging of malignant lesion To collect material for ancillary studies such as flow cytometry , microbial culture etc.

8. Advantages of guided lesions Area of interest or more representative part of tissue can be sampled. Small lesion can be sampled. Non palpable and deep seated lesion can be asessed . Injury of major structure is avoided. Necrotic tissue or cystic area is avoided.

9. Imaging modalities The deep seated lesions can be aspirated under the guidance of – Ultrasonography - Computerised Tomography - Magnetic Resonance Imaging - Fluoroscopy - Ultrasound guided Endoscopy

10. Ultrasound Ultrasound is the only real-time guidance which allows imaging in any plane and only suitable guidance for biopsy of fetal tissue. If the suspected tumor is in the deeper planes and cannot be seen or felt by the physician, then the patient is asked to get an ultrasound-guided biopsy. High frequency sound wave is applied and the reflection of the wave from tissue interface is recorded to construct the image.

11. Technique of USG guided biopsy The longest part of examination is identifying the lesion, positioning the patient, identifying the site of puncture and direction of the needle. The depth of the lesion from the skin surface is measured to determine the length of the needle required. Continuous real time ultrasound is used to visualize the needle entering the lesion and also during aspiration to ensure that the needle stays within the lesion.

12. Procedure Preprocedural evaluation Patient consent and pre-procedure targeted physical examination A pre-procedure targeted ultrasound examination Equipment 22 gauge to 27 gauge needle with a stylet . Generally a 3.5 – 5 Mhz transducer is used for biopsy, however a linear/superficial probe is useful in case of neck masses and breast lesions. 1%/2% lidocaine without epinephrine Betadine and spirit swabs 50cc and 20cc syringes 10 glass slides for tissue separation

13. Positioning For most of the lesions as in case of liver, pancreas, GIT, neck etc., the patient is positioned in supine or lateral decubitus position with maximum access to the location of the lesion. For lung or pleural biopsy patient can be either made to sit upright or lie down in lateral decubitus position . For FNA biopsy from breast, patient is positioned in the dorsal decubitus or lateral decubitus . Probe Sterilization The transducer must be sterilized before its use by betadine and spirit swabbing.

14. Biopsy procedure The transducer is ideally held in the optimal longitudinal position to visualize the lesion. Prior to insertion of needle ,the alignment of transducer is checked. Under real time guidance the needle is introduced through skin,1-2 cm proximal to the transducer and then advanced along the line of the transducer. The length of the needle should become visible and tip is seen to puncture the lesion, then inserted few more millimeters. It is only when the needle and lesion are in line ,that a successful puncture can occur.

15. Indications a suspicious solid mass a distortion in the structure of the viscera an area of abnormal tissue change Sites thyroid non-thyroid neck breast liver lymph nodes lung gastrointestinal tract Mediastinum Pancreatic mass

16. Advantages Real time Easy to do Portable No radiation exposure Angular approach can be done Better precision

17. Disadvantages Significant obscuration due to air or bone may affect the image. Not very high resolution Completely operator dependant

18. Postprocedural care There is no standardized postprocedure care for FNA. Compression of the biopsy site with gauze is common to control minor local bleeding. If the lung is biopsied, a post procedure radiograph may be obtained. In case of liver and pancreas biopsy, patient is made to lie in right lateral and prone positions respectively.

19. Complications 3 Uncommon with appropriate FNA technique, usually limited to bleeding or infection. Pneumothorax is a risk of lung biopsies. Either a postprocedure radiograph or ultrasound may be obtained to look for this complication.

20. Endoscopic ultrasound-Guided FNAC Technique: At first, lesion is localised by endoscopic ultrasound. A 22 guage needle with an internal stylet is used for FNAC. The needle with stilette is introduced through endoscope to the mass under EUS guidance. The stilette is withdrawn and aspiration is done with the help of 20 cc syringe by applying negative suction. After suction the needle is withdrawn and material is expelled by reintroducing the stilettewithin needle.

21. Endoscopic Cytology Can Be Used in Staging of esophageal, gastric and rectal cancer Evaluation of abnormalities of the gastrointestinal wall or adjacent structures ( submucosal masses, extrinsic compression) Evaluation of thickened gastric folds Diagnosis and staging of pancreatic cancer Evaluation of pancreatic abnormalities (suspected masses, cystic lesions including pseudocysts , suspected chronic pancreatitis)

22. Staging of ampullary neoplasms Diagnosis and staging of cholangiocarcinoma Diagnosis and evaluation of deep seated lymphadenopathy Diagnosis of diseases of spleen Parasitic infestation EUS guided mediastinal lymph node FNA

23. Gastrointestinal Endoscopic Cytology Important modality in the evaluation of luminal gastrointestinal diseases as well as diseases of the spleen, pancreas, gallbladder and biliary ductal system. Sampling techniques can be 1.Blind lavage 2.Blind abrasive 3.Directional brush and wash method using an endoscope

24. Sample Collection After introduction of the endoscope , the upper G I is inspected, any lesion found is photographed, then first cytological and then biopsy sample is obtained. Cytological sample can be collected by two ways: Directional brush and Directional wash

25. Directional Brush Sampling For brush sample collection smaller brushes enclosed within transparent teflon sheath ,. The brush sample when obtained, is pulled back within the teflon sheath, and the whole sheath is withdrawn. To obtain the sample the brush is plunged firmly and briskly into the mucosa 5 – 10 times so that the lamina propria is penetrated. Otherwise it fails to obtain a reliable sample and may lead to a false-negative result . Cytological brushing also has the many advantages such as acceptance by the patients, good penetration to the basement membrane, collecting cells from all three epithelial layers and early diagnosis of upper GIT lesions.

26. Directional Wash Sampling Simple To obtain the wash sample, the opening of a teflon tube is directed at a particular lesion at close quarters and forceful injection of buffered saline solution is aimed at the site. Immediate suction with a syringe that injected the fluid results in salvage of cells in that area.

27. Wash v brush For collection from the stomach, washing is superior, but in both the esophagus and colon, brushing techniques are more accurate.

28. Limitation

29. Advantage Fiber cells

30. Gastrointestinal Stromal Tumor The cellular aspirate from a obtained from a duodenal mass reveals sheets of spindled cells with wispy cytoplasm. The nuclei are elongated with some showing nuclear angulation

31. EUS FNA Of Pancreatic Lesions ERCP permits visualization of pancreatic duct and hepatobiliary tree. EUS FNA has become a preferred method for localization and aspiration biopsy of the pancreatic lesions. Objective: To detect and determine the extent of the lesion To obtain pre operative tissue diagnosis and staging for malignancies for a clinically suspicious malignancy.

32. Approaches to perform EUS FNA for lesions located at different sites in pancreas. Location of the lesion Approach Head/Uncinate process Transduodenal Body/Tail Transgastric

33. Solid Pancreatic Masses Differential Diagnoses For Solid Pancreatic Masses Benign Malignant Chronic pancreatitis Carcinoma Islet cell tumour Ductal adenocarcinoma and its variant Abscess Metastatic carcinomas Infection Acinar cell carcinoma Malignant islet cell tumour Metastatic non epithelial malignancy

34. Cystic Pancreatic Masses Differential diagnoses for pancreatic cystic lesions Non neoplastic Neoplastic Pseudocyst Mucinous cystic neoplasms Lymphoepithelial cyst Intraductal papillary mucinous neoplasm Dermoid cyst Solid cystic papillary neoplasm Islet cell tumours Serous microcystic adenomas Macrocystic adenomas

35. Normal ductal epithelial cells

36. Chronic Pancreatitis Endoscopic ultrasound-guided fine-needle aspiration sample from a case of chronic pancreatitis that shows a cohesive 2-dimensional group of ductal epithelial cells. Individual cells show a preserved nuclear/cytoplasmic ratio and regular nuclear membrane (Papanicolaou, ×40)

37. Malignant cells ( adenocarcinoma ) cluster of pleomorphic cells

38. Respiratory Tract Cytology By Bronchoscopy Flexible fibreoptic bronchoscope is used to carry out the endoscopic cytology of respiratory tract Techniques Bronchial aspirate and washing Bronchial brushing Bronchoalveolar lavage Transbronchial FNA

39. Bronchial Aspirate and Washing Introduction of the bronchoscope into the lower respiratory tract enables the examiner to obtain samples by means of a suction apparatus that aspirates the secretion. Washing from the visualized area may also be collected by instilling 3 – 5 ml of balanced salt solution through the bronchoscope and re-aspiration of resulting material.

40. Bronchoalveolar Lavage Bronchoalveolar lavage involves the infusion and re-aspiration of sterile saline solution in distal segments of lung via fiberoptic bronchoscope . Diagnostic use Lung cancer Evaluation of interstitial lung disease Opportunistic infection in immuno compromised patients

41. Bronchoalveolar Lavage Therapeutic use Pulmonary alveolar proteinosis Cystic fibrosis Pulmonary alveolar microlithiasis Asthma

42. Complications of Endoscopic Cytology Complications related primarily to sedation (cardiovascular and respiratory depression, aspiration) Perforation Bleeding Pancreatitis ( ERCP) Cholangitis ( ERCP) Wound infections

43. Computed Tomographic scan guided FNAC Computed Tomographic scan is one of the popular imaging modalities to guide FNAC. CT uses X-ray beam to create multiple tomographic or cross sectional images of the body depending on the ability of the tissue to block the Xray . This ability of the tissue to absorb radiation depends on the tissue density.

44. It provides detailed cross sectional images of the body which are not limited by same physical properties as are ultrasound images, such as interference from bowel gas and bone. The computer accumulates the data and produces multiple images in different planes.

45. Advantages : High resolution Exact localisation of needle possible Operator independent Deep lesion near vital structure needs CT guidance Disadvantages: Costly Time taken procedure Good radiation exposure

46. Magnetic resonance image guidance Radiofrequency energy is used No radiation exposure Costliest Time consuming Special euipments are needed to avoid the disturbanced of magnetic field Selected cases in breast, lung and soft tissue of head and neck regions are done.

47. Pitfalls in aspiration biopsy Occasional errors may include: Maintaining negative suction while withdrawing the needle, aspirated tissue is then sucked into the syringe Excessive suction: only 1-2 cc of suction via 10ml syringe is required to provide adequate tissue, greater aspiration pressures increase blood aspirates and may traumatize the tissue. Deviation of needles: This may be due to tissue planes or tough capsules on lesion,e.g-fibroadenoma , which causes the tip to deviate around mass.

48. Obtaining bloody aspirates : The use of longer coaxial needle may prevent hemorrhagic aspirates. French technique can be use to avoid bloody aspirates. Maintaining a fixed system which can tear tissues. It is important not to hold the needle while the patient is breathing or moving. Poor aspiration technique: Needle manipulation must be practiced-it should be oscillated 1-2 cm depending on size of the lesion.

49. Poor smearing technique: smearing the aspirate on slide should perform by trained cytologist. Forgetting to remove the stilette from needle when using french technique where no aspiration is used.