Cytology Diagnostic Aids PDF

Cytology Diagnostic Aids FdSc Veterinary Nursing Level 5 Cytology Cytology = Study of cells (Histology = study of tissues) Look for: - cells which are abnormal - cells which indicate inflammation/infection Also use samples to look for: - bacteria/fungi/protozoa...

Cytology Diagnostic Aids FdSc Veterinary Nursing Level 5 Cytology Cytology = Study of cells (Histology = study of tissues) Look for: - cells which are abnormal - cells which indicate inflammation/infection Also use samples to look for: - bacteria/fungi/protozoa - protein and other biochemical tests - general appearance of sample 2  Fluids Others haematology swab urine sediment scrape thoracentesis Cytology body cavity impression smear pericardio- fluids Samples centesis endoscope brush abdominocentesis tap fine needle wash aspirate joint CSF bronchus prostate 3 ‘-centesis’ -centesis – from Greek Greek ‘to puncture’ ie use needle and syringe Sometimes called a ‘tap’ Thoracentesis/thoracocentesis Abdominocentesis Pericardiocentesis Arthrocentesis Myelocentesis 4 BODY CAVITY EFFUSIONS 5 Abdominocentesis Needle/butterfly (19g), can attach to syringe via 3-way tap Sterile preparation, may need LA block Standing (or lateral) Manual restraint Most dependent part ventral midline (or 4 quadrant) 6 Thoracentesis (thoracocentesis) iv catheter (19g) (or needle/butterfly) attached to syringe via 3-way tap Sterile preparation, may need LA block Sternal or standing Manual restraint or light sedation 7th intercostal space, ventral 1/3 , at an angle to minimise risk of entering lung Pneumo- thorax reduction Risk lung damage Thora- centesis 7 Pericardiocentesis iv catheter (19g) (or needle/butterfly) attached to syringe via 3-way tap Sterile preparation, may need LA block, side decided after X-ray Usually sternal recumbency Manual restraint or light sedation Usually enter 4th-5th ic space 8  Microscopy: - Cells - Bacteria Refractometer protein Culture and Sensitivity Analysis of fluids Haematology PCV Biochemistry Urine dipstick: -WBC -RBC 9 Evaluation of Effusion Samples Appearance – colour, smell, turbid, floccular (bits in it) Total protein (TP) Total nucleated cell count (TNCC) Cytology – smear may see? Biochemistry e.g. creatinine, bilirubin 10 Classifying Effusions TP + TNCC – used to classify effusions Total Protein (TP) Measure with refractometer, urine test strips, biochem analyser Ideally determine albumin and globulin concentration Total Nucleated Cell Count (TNCC) May be serous membrane (mesothelial) cells or leucocytes Measure with haematology analyser or haemocytometer (special slide) 11 Causes of Effusions Leak from viscus e.g. bladder, gall bladder, gut Torn vessel – blood or lymph Leakage from intact blood vessels 12 Leak from Viscus Digestive tract Biliary tract 13 Urinary tract Types of Effusion: Leak from Viscus Effusion A – initially low nucleated cell count, low total protein, high creatinine (> 2 x serum) Effusion B – initially low nucleated cell count, low total protein, green-brown or yellow-brown, high bilirubin (> 2 x serum) Effusion C – high nucleated cell count, high protein, ± foul smelling, ± food debris A B C 14 Leak from torn vessel Blood vessels Lymph vessels Leak: Leak: Haemothorax Chylothorax Haemoabdomen Chyloabdomen NB After lymph has picked up fats from intestine, it looks like15milk and is called ‘chyle’ Types of Effusion: Vessel Tears Effusion D: Very high nucleated cell count (esp lymphocytes), high total protein, high fat Lymphocytes in chylous effusion Effusion F: Many RBC (PCV> 5%), high nucleated cell count, high total protein erythrophagocytosis 16 Effusion: Leakage from Blood Vessels Low protein transudate: Low protein in plasma → water leaks High protein transudate: ↑ blood pressure → water and protein leak Exudate: leaky capillaries due to inflammation → water, protein and cells leak 17 Types of Effusion: Transudate and Exudate Low protein transudate – low nucleated cell count, low total protein Causes? High protein transudate – low nucleated cell count, high total protein Causes? Exudate – high nucleated cell count, high total protein Causes? Low protein High protein Exudates transudate Transudate 18 Types of Effusion Effusion Total Total Appearance Other nucleated Protein features cell count (TP) (TNCC) Torn Viscus Urinary tract Low Low Pale yellow High creatinine Clear Biliary tract Low Low Yellow or green High bilirubin Clear Digestive tract High High Yellow or brown May see gut Turbid, floccular contents Torn Vessels Blood High High Red or brown Many RBC Turbid Lymph High High White or pink Much fat & Turbid lymphocytes Leaky Vessels Transudate – Low Low Pale or colourless - low protein Clear Transudate – Low High Yellow - high protein Clear Exudate High High Yellow - 19 Turbid MYELOCENTESIS: SPINAL TAP 20 Myelocentesis – why do it? Indications Investigate CNS disease of unknown cause Contraindications Requires GA, so anything which contraindicates this Increased intracranial pressure – could be brain herniation 21 CSF Sampling Cisterns – where there is a widening of space filled with CSF GA, full prep, insert spinal needle – allow fluid to drip out (do NOT use syringe) ~ 1ml/5kg Plain and EDTA collect cells 22 ARTHROCENTESIS: JOINT TAP 23 Arthrocentesis – why do it? Joint disease of unknown aetiology Joint effusion Disease of multiple joints (sample at least 3 joints) Suspected infective arthritis Pyrexia of unknown origin (PUO) 24 Arthrocentesis Sample Collection GA or heavy sedation/LA Aseptic prep (wear sterile gloves to palpate landmarks) Attach syringe to needle prior to insertion and apply gentle suction. In dog usually 0.1-1.0ml fluid per joint Fluid → EDTA, plain and blood culture bottles + squash or smear 25 Normal Appearance of Joint Fluid Clear to slightly yellow Clear Viscous 26 RESPIRATORY TRACT CYTOLOGY 27 Obtaining Samples Samples obtained by: Transtracheal aspiration Endotracheal tube Flexible endoscope – bronchoalveolar lavage (BAL) 28 Why do it? Investigate chronic airway/lung disease e.g. due to inflammation, infection, neoplasia Contraindications – insufficient gaseous exchange… definitely not if dyspnoeic! 29 Bronchoalveolar Lavage GA Oxygen therapy before and 10 min after; monitor carefully! Cat may need bronchodilator Insert endoscope into bronchus. Large volume of saline injected flooding the alveoli associated with that bronchus (10ml for cat/small dog, 25ml for large dog) Aspirate fluid - only a small proportion of sample is aspirated – improve by coupage Plain, EDTA, smear/squash 30 FINE NEEDLE ASPIRATE 31 FNA Indications Differentiate between masses which may be: infectious/traumatic/inflammatory/neoplastic If considering surgical removal of a mass, FNA can aid in determining the margins needed. Can be performed conscious 32 Method: With Aspiration 33 Method: Without Aspiration Capillary action pushes cells up needle. Useful for masses where cells break away easily and if cells likely to burst if much pressure e.g. lymphoma 34 Needle and Syringe Size Needle Soft masses: 23-25g Firm masses: 21-22g Syringe No aspiration – syringe doesn’t matter Aspiration – soft mass: 1-3 ml – firm mass: >3ml – apply more pressure 35 Potential Problems Good Miss target Centre filled with necrosis/pus Benign lesion Fibrosis and next to scar tissue 36 malignant Fine Needle Aspiration Device Used to apply exact amount of pressure 37  FNA: Slide Preparation Squash preparation – aspirate expelled onto middle of slide, a second slide is placed on top at right angles to spread sample, then spreader drawn smoothly across bottom slide. NO pressure or rupture cells! NB Often spreader gives best smear. 38 Summary Cytology involves collecting cells from the body and examining under microscope (may also see other cells e.g. bacteria, fungi) Cytology can be performed on: – Fluids e.g. effusions in body cavities, cerebrospinal fluid, joints – Lavage samples – sterile fluid is added and then aspirated – Solid masses e.g. final needle aspirate, bone marrow aspirate Effusions – often measure protein and cells within fluid to determine what the fluid is. Need EDTA tube + plain tube + smear 39