Laboratory diagnosis of cancer

Laboratory diagnosis of cancer (FNAC & Histopathology)

1. Laboratory Diagnosis of Cancer (FNAC & Histopathology) Dr. MD. SAIDUZZAMAN SAYID MBBS, BCS (Health) Lecturer Department of Pathology Dinajpur Medical College, Bangladesh

2. Laboratory Diagnoses of Cancer Cytology Histopathology Immunohistochemistry Molecular and cytogenetic diagnosis Flow cytometry Tumour markers Electron microscopy

3. Cytology: Study of individual cells Fine needle aspiration cytology (FNAC) Direct Image guided Exfoliative cytology Abrasive cytology

4. FNA consist of four coordinates steps Palpation Aspiration Smear preparation Fixation & Staining Microscopy

5. FNAC with aspiration

6. PROCEDURE: EQUIPMENTS NEEDLES: Routinely 22-23 gauge needle used. Syringes: 5-10 ml syringe Pistol handle

7. FAILURE TO OBTAIN A REPRESENTATIVE SAMPLE Needle has missed the target tangentially Needle in central cystic/necrotic/hemorrhagic area devoid of diagnostic cells. Needle in dominant benign mass missing a small adjacent malignant lesions. Fibrotic/ desmoplastic target tissue giving a scant cell yield.

8. PITFALLS OF FNAC Deviation of needle Poor aspiration technique Poor smearing technique Maintaining negative suction while with drawing the needle. Excessive suction Forgetting to remove the stilette from the needle Obtaining bloody aspirate.

9. FIXATIVES Fixatives commonly used 95% ethyl alcohol.

10. STAINS Smear stain by Papanicolaou stain.

11. ADVANTAGE OF FNAC Simple technique , no hospitalization is required Wide patient acceptance due to less trauma. Rapid diagnosis Economical Sampling from multiple sites in the same sitting High diagnostic accuracy Many techniques such as bacterial culture, immunocytochemistry , flow cytometry , cytogenetics , polymerase chain reaction, etc. are possible from FNAC material.

12. DISADVANTAGE OF FNAC Loss of tissue architecture Capsular invasion and lymphovascular invasions cannot be detected Difficult to differentiate in situ versus invasive carcinoma Considerable training is needed for accurate interpretation. May produces complications, e.g. Bleeding, infection.

13. FNAC Complications FNA is considered one of the safest invasive diagnostic procedures though complications were estimated at 0.03% of cases. 1)Hematomas 2)Infection 3) Pneumothorax

14. Contraindication Bleeding Obstructive Emphysema or pulmonary hypertention Pancreatitis Bacteraemia/septicemia

15. THE PRACTICE OF FNAC Success of FNAC depends on four fundamental requirement: Samples must be representative of the lesion investigated. Samples must be adequate in terms of cells & other tissue components Samples must be correctly smeared and processed FNAC must be accompanied by relevant and correct clinical/radiological information.

16. Radiological aids in FNAC Plane X-ray film: for lesion in bone and for lesions in the chests CT:for lesions in chest and abdomen USG guidance: which allows direct visualization of needle placement in real time and free from radiation hazards Image amplified fluoroscopy

17. Histopathology Histopathology : Gross & microscopic study of diseased tissue. Biopsy : Removal of tissue from living body for diagnostic purpose. Autopsy : Removal of tissue from dead body to find out the cause of death.

18. Differentiation and Anaplasia Differentiation : Refers to the extent to which neoplastic cells resemble comparable normal cells, both morphologically and functionally. Anaplasia : Lack of differentiation is called anaplasia .

19. GRADING The grade of a cancer is an assessment of its degree of malignancy or aggressiveness. Grading is done on degree of differentiation of the tumor cells (degree of resemblance to normal counterparts). Classified as grades I to IV with increasing anaplasia .

20. GRADING Grade I : More than 75% cell differentiation. Grade II : 50 to 75% cell differentiation. Grade III : 25 to 50% cell differentiation. Grade IV : Less than 25% cell differentiation.

21. STAGING Staging : Extent of spread of cancer Staging of cancer is based on: Size of the primary lesion Extent of spread to regional lymph node The presence or absence of blood borne metastasis

22. STAGING TNM system: TNM staging varies for specific forms of cancer, but there are general principles. T for primary tumor N for regional lymph node M for metastases

23. STAGING With increasing size of primary tumor: T1-T4, in situ-T0 N0 → No nodal involvement N1 to N3- involvement of increasing number and range of node M0 → No distant metastases M1 and M2-present of blood borne metastases Grading of cancer has proved less clinical value than staging.

24. IMMUNOHISTOCHEMISTRY Immunological method of recognizing a cell, based on recognition of specific components called “antigens”

25. IMMUNOHISTOCHEMISTRY: USES Categorization of undifferentiated malignant tumor Specific typing of leukemias /lymphomas. Determination of site of origin of a metastatic tumor. Detection of molecules that have prognostic & therapeutic significance, e.g.,ER -PR receptors in carcinoma breast. Expression of protein products of oncogenes . Differentiating benign from malignant lesions.

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