RCI I Cytology and Histopathology-MVIC PDF

Integrated Masters in Veterinary Medicine Cytology and Histopathology Integrated Clinical...

Integrated Masters in Veterinary Medicine Cytology and Histopathology Integrated Clinical Reasoning I 2024/2025 Marisa Vicente BSAVA PGCertSAM, MSc, MRCVS [email protected]  Cytology Non-invasiveness Availability Often times no need for sedation/ anaesthesia Good evaluation of cell morphology FNA – Fine Needle Aspiration Minimal haemorrhage risk Cost effective FNB – Fine Needle Biopsy No information on tissue arquitecture Cytology - Sampling Techniques Fine Needle Aspirates Impression smears Scrapings Swab smears Cytology – Sampling Techniques Fine-Needle Aspiration Soft Tissue Masses Cutaneous lesions Lymph nodes Intra-thoracic or intra-abdominal masses Effusions from body cavities Cytology – Sampling Techniques Fine-Needle Aspiration Cytology – Sampling Techniques Fine-Needle Aspiration Equipment Needed Glass slides with a frosted end for labelling 5 ml syringe (10ml if very firm mass) 20 – 22G needle Pencil for labelling Cytology – Sampling Techniques Anatomy of a Syringe and Needle Shaft Cytology – Sampling Techniques Fine-Needle Aspiration Technique Non-Aspiration Aspiration Technique Technique Poorly exfoliative Highly vascular masses masses or organs Very firm masses Cytology – Sampling Techniques Fine-Needle Aspiration “Aspiration Technique” Imobilize the mass FNA of intra-cavity Needle with attached with one hand and the organs/ masses Desinfect skin syringe is inserted into syringe and needle should be done under the lesion with the other ultrasound guidance pull back Plunger is withdrawn and Fill syringe with 3-5 ml while maintaining of air and reattach to Remove needle and Detach syringe from negative pressure, needle to expel the syringe after releasing needle redirect the needle to aspirate gently on the the plunger aspirate diferente regions glass slide. of the mass/organ Cytology – Sampling Fine-Needle Aspiration Techniques “Aspiration Technique” Cytology – Sampling Techniques Fine-Needle Aspiration Non-Aspiration Technique Needle- Needle and alone syringe pre- technique filled with air Cytology – Sampling Techniques Fine-Needle Aspiration Slide Preparation Expulsion Rotating Smear Squash Cytology – Sampling Techniques Slide Preparation Expulsion Immediately after sampling Syringe pre-filled with If bloody or abundant 3-6 mL of air and material, it can be attach to the needle more gently expulsed containing the sample and distributted Quickly depress the Angle the needle bevle plunge to propel side down close to sample towards the proximal (frosted) edge slide Cytology – Sampling Techniques Fine-Needle Aspiration Smear ✓ Fluid material → 45º angle ✓ Gently to avoid cell rupture ✓ Highly viscous fluid → 25º angle (eg synovial fluid) Cytology – Sampling Techniques Fine-Needle Aspiration Squash Cytology – Sampling Techniques Fine-Needle Aspiration Slide Preparation Expulsion Rotating Smear Squash Cytology – Sampling Techniques Fine-Needle Aspiration Rotating  Cytology – Sampling Techniques Use different sample collection and slide Do at least 3 slides from preparation methods to each lesion maximize chances of getting a diagnostic slide If analyzing in house - Keep a slide to yourself if keep one unstained to possible send to a pathologist Cytology – Sampling Techniques Ultrasound- Guided Fine Needle Aspiration To determine if a lesion represents inflammation, infection or neoplasia Staging for neoplastic disease Abdominocentesis, pleurocentesis, pericardiocentesis Cytology – Sampling Techniques Ultrasound- Guided Fine Needle Aspiration Cytology – Sampling Techniques Locations Suitable for Ultrasound- Guided FNA Abdominal Thoracic Cervical Liver Lungs Thyroid Glands Gallbladder Mediastinum Parathyroid Glands Spleen Pleural and Thoracic Wall Regional Lymph nodes Gastrointestinal Tract Lesions Adrenal Glands Pancreas Prostate Gland Bladder Kidneys Ovaries Uterus Lymph Nodes Mesenteric Masses Abdominal cysts and abscesses  Cytology – Sampling Techniques https://todaysveterinarypractice.com/diagnostics/ultrasound-guided- fine-needle-aspiration-and-core-biopsy/ Potential Complications of Ultrasound- Guided FNA Cytology – Sampling Techniques Impression Smears/ Imprints Exsudative Lesions – Slide Dry lesions/skin – sellotape Only collects cells from surface of lesion Bacterial contamination more likely Cytology - Sampling Techniques Fine Needle Aspirates Impression smears Scrapings Swab smears Cytology – Sampling Techniques Scrapings Cytology – Sampling Techniques Swab Smears Ear canal Vaginal Fistulous tracts Cytology Slide Processing – External Laboratory Give as much information about the lesion to the pathologist as possible. Cytology Slide Processing – Inhouse Evaluation At low speed. Fixative – Eosinophilic Basophilic – Methanol - Eosin Thiazine 10 Dips, 1 10 Dips, 1 5 Dips, 1 sec sec each sec each each Cytology Microscopic Evaluation of Cytological Specimens Scan at low magnification (4X or 10X Assess celular objective) to identify composition with the áreas of increased 20X objective. cellularity 40X objective and 100X oil immersion lens allows evaluation of cell morphology in greater detail  Aim to answer these questions … Microscopic Evaluation of Cytological Is que quality of the specimen good enough to evaluate? Specimens Are the cells present normal for this anatomical site? Is the lesion inflammatory, reactive or non-inflammatory? If inflammatory, what is the predominant inflammatory cell type/s and is an aetiology agent presente? Eg bacterial/ fungal infection If non-inflammatory, is the lesion neoplastic, hyperplastic or dysplastic? If neoplastic, what is the origin of the cells present and is the lesion benign or malignant?  Cytological Terminology Term Definition Anisocytosis Variation in cell size Anisokaryosis Variation in nuclear size Hyperplasia A reversible increase in cell numbers, caused by increased mytotic activity in response to a stimulus Neoplasia Uncontrollable cell multiplication, progressive and irreversible. Neoplastic proliferation of cells is driven by somatic mutations/ alterations in cell cycle control, and cell differentiation is often impaired Metaplasia Reversible process where one mature cell type is replaced by another mature cell type. Dysplasia Reversible proliferative celular changes that occur in response to irritation or inflammation. Characterized by abnormal size, shape and organization of mature cells. Anaplasia Lack of celular differentiation. Poorly differentiated tumours are generally more malignant. Chromatin pattern Microscopic appearance of the nuclear chromatin. It becomes more coarse as malignant potential increases.  Histopathology Study of tissue samples from various organs, such as the liver, spleen, skin, and lymph nodes, to examine and identify any abnormalities or diseases present.  Cytology VS Histopathology Feature Cytology Histopathology Focus Individual cells Whole tissue structure Sample Biopsies, surgical Aspirates, fluids, smears specimens Purpose Initial screening, cellular Detailed diagnosis of abnormalities tissue-based diseases Invasiveness Minimally invasive Invasive Turnaround time Faster Slower Accuracy Gold standard for Good for initial screening diagnosis Histopathology - Biopsies Minimally Invasive Techniques Trucut Endoscopic Histopathology - Biopsies Minimally Invasive Techniques Trucut Automatic Semi-automatic Economical and Needle tip is precise NOT ejected Needle tip is beyond the ejected beyond needle the needle visualization placement point point Histopathology - Biopsies Minimally Invasive Techniques Trucut 14 – 18 – gauge Better visualization on ultrasound Superior samples Higher rate of complications – haemorrhage Patients must be heavily sedated or anaesthetized Biopsies - Minimally Invasive Techniques Trucut Fine Needle Aspiration Versus Trucut Biopsy Indications FNA Trucut Biopsy Small, solid masses Cystic lesions Highly vascular lesions Diffuse infiltrative disease Large masses Histopathology desired Biopsies - Minimally Invasive Techniques Endoscopic Endoscopic biopsies sample a tiny percentage of the mucosa. Take multiple (6–10) biopsies of each site. Fast recovery Lower risk of complications (e.g. dehiscence, septic peritonitis) Upper GI access only to stomach and duodenum; lower GI tract preparation and endoscopy is needed to assess and sample the ileum and colon. Lesions in jejunum may be missed No sampling of liver, lymph nodes etc. Samples may be subject to artefacts (crushed and fragmented samples) Expertise performing endoscopy and specific equipment required Histopathology - Biopsies Punch Biopsies Histopathology - Biopsies Punch Biopsies Diffuse disease – sample several sites to get a range of the lesions Avoid áreas of necrosis, ulceration and secondary infection as they may obscure the primary lesion Biopsy intact vesicles or pustules Large lesions – multiple biopsies. Histopathology - Biopsies Specimen Sizing The larger the specimen, the higher the probability of getting a diagnosis. Excisional Biopsy Incisional Biopsy “First, do no harm” Client Preference Cost Histopathology - Biopsies Specimen Sizing Incisional Biopsy Excisional Biopsy Interface between lesion and healthy tissue – maturation of reactive tissues, invasive growth of malignant tumours, margins. Histopathology - Biopsies Incisional Biopsy - GIT https://drstephenbirchard.blogspot.com/2013/09/intestinal-biopsy- A sample that includes all the layers in the stomach or small intestine can be obtained. During surgery, all the parts of the small intestine can be accessed and biopsied, as necessary. Any areas that are seen to be abnormal from the outside layer can be specifically tested. Biopsies can also be taken from lymph nodes and other organs in the abdomen such as the pancreas and liver at the time of surgery. Risk of dehiscence and septic peritonitis. when-and-how.html Histopathology - Biopsies Biopsy Specimen Place tissue in neutral Submit in leak and buffered 10% formalin shatter proof, Fixation (up to 48 Macroscopic immediately after collection. 10:1 formalin labelled, hours) examination to tissue volume. container. Microtomy and Processing (2 – Embedding in placing sections Staining overnight) paraffin wax into glass slides Histopathology - Biopsies Submission Form Signalment and clinical history Species, breed, reproductive status, pertinent clinical signs, previous treatment, response to treatment, weather others in the environment are affected… Lesion description Nº, location, distribution, size, colour, shape, consistency, other. Differential diagnosis and specific questions Clinicopathologic correlation  Biopsy Tecniques Modified graph from Stromberg, P.C. (2009) The principles and practice of veterinary surgical pathology. Questions? References