TV4101 - Cytology Part 2 - Lymph Nodes

Lymph node cytology

Enlarged lymph nodes - disease

Top 5 cytological findings?

1. Reactive or hyperplastic lymph node

2. Lymphoma

3. Lymphadenitis

4. Metastatic disease

5. Accidental salivary gland aspirate

Lymph node cytology

Enlarged lymph nodes - disease

Reactive or hyperplastic lymph node

Occurs when?

Cell Features?

With local or systemic immune stimulation

Cells

• Small Lymphocytes predom

• 15 - 25% inc in medium & large lymphocytes

• Reactive class- if inc plasma cell numbers

Lymph node cytology

Enlarged lymph nodes - disease

Reactive or hyperplastic lymph node

What is the red arrow? Features of each?

Blue arrow?

Red -Plasma cell

• <5%

• Eccentric nuclei

• Condensed chromatin

• Abundant deeply basophilic cytoplasm with a perinuclear clear area (golgi region)

• Similar size to neutrophil

Blue arrow - Neutrophil

Lymph node cytology

Enlarged lymph nodes - disease

Lymphoma

Features of this?

Most common haemopoietic tumour in dogs & cats

Neoplastic malignant proliferation of lymphoid cells arising in peripheral lymphoid tissue (e.g. lymph nodes & spleen)

Lymph node cytology

Enlarged lymph nodes - disease

Lymphoma

Cyto Dx?

• Majority ( > 50%) of lymphocytes are immature (lymphocytes are intermediate or large)

• Easier if lymphocytes contain prominent nucleoli

  (finely granular to dispersed chromatin)

• Small cell lymphoma difficult to DX

Lymph node cytology

Enlarged lymph nodes - disease

Lymphoma

Classification

Main principles include?

Main principles:

Anatomic location

Cellular morphology

Tissue architecture,

Immunophenotype and genetics

Lymph node cytology

Enlarged lymph nodes - disease

Lymphoma

Classification and cytology aspect?

Cytology: use morphology to classify into high – grade and low grade & then distinguished by phenotype (T or B cell)

Lymph node cytology

Enlarged lymph nodes - disease

Lymphoma

Classifications - Important Parameters and Lymphoma types

Lymph node cytology

Enlarged lymph nodes - disease

Lymphoma

How it Mitotic Index determined?

Counting the number of mitoses in 5 HPF (on 50x objective)

Lymph node cytology

Enlarged lymph nodes - disease

What is this?

Large cell high grade lymphoma

Lymph node cytology

Enlarged lymph nodes - disease

What is this?

Small cell low grade lymphoma

Lymph node cytology

Enlarged lymph nodes - disease

Submandibular lymph node was enlarged and underwent FNA - what can we see here?

DX?

White arrows - Cohesive clusters of vacuolated, secretory epithelial cells from salivary gland

Blue - RBCs

Black - Nuclear remnants of ruptured cells

Accidental salivary gland aspiration

What is this?

Describe what we can see?

DX?

Windrowing

Lining up of RBCs in a linear array due to the viscosity of saliva (eosinophilic material in the background)

Accidental salivary gland aspiration

Lymph node cytology

Metastatic disease

What do we see?

A marked increase in cells ( & clustering) found in lymph nodes (e.g. mast cells)

Presence of cells not expected in a lymph node (e.g. epithelial cells – raise suspicion)

What is this?

Metastatic Dz

Body cavity effusions

Health (canine & feline)

Normal features?

Body cavity effusions

“Simplified” laboratory criteria for classification

Need to know detail:

Step 1 [protein]

Step 2 [cell]

Body cavity effusions

What should we observe to help dx?

1. Macroscopic appearance of fluid (colour – yellow, red; smell – urine)

2. Measure protein (g/L) concentration

3. Determine automated total nucleated cell count (x 109/L)

4. Cytology – evaluate direct and cytocentrifuged preparations

Body cavity effusions

Transudative effusions

Colour?

Protein?

Nucleated cells?

Cell Characterisitcs?

Body cavity effusions

Exudative effusions

Predominantly characterised by? Why? Steps involved?

High cellularity and high protein concentration because they are formed due to an inflammatory process

Body cavity effusions

What is this? Why?

Exudate - sterile or septic

Cloudy & sediment

Body cavity effusions

What is this?

Why?

Sterile or Septic Exudative Effusion

Predominantly neutrophils – degenerate morphology if infectious (septic)

Body cavity effusions

What is this?

Why?

Exudate viral – FIP

Moderately Yellow

Body cavity effusions

What is this?

Why?

Granular proteinaceous (high protein) background & low cellularity

Exudative effusion – FIP

Body cavity effusions

Haemorrage - trauma, coagulopathy, neoplasia

Acute version

Colour?

Nucleated characteristics/ Microscopy?

Body cavity effusions

Haemorrage - trauma, coagulopathy, neoplasia

Chronic version

Colour?

Nucleated characteristics/ Microscopy?

Body cavity effusions

What is this?

DX?

Haematoidin crystal

Chronic Haemorrage

Body cavity effusions

What is this?

DX?

Haemosiderophage

Chronic Haemorrage

Body cavity effusions

What is this?

DX?

Erythrophagocytosis

Chronic Haemorrage

Body cavity effusions

Lymphorrhage - means what?

How does it occur? Result?

Lymphatic Effusion from obstruction (physical or functional) to lymphatic flow (thoracic duct into venous system) → Increased pressure and dilation of lymphatics (lymphangiectasia)

Body cavity effusions

Lymphorrhage

Specific ways it occurs?

Body cavity effusions

Lymphorrhage

Types of effusion?

Chylous effusion and Nonchylous lymphatic effusion

Body cavity effusions

Lymphorrhage - Chylous effusion

Features (general)

Lymphatic vessel btw SI and thoracic VC is affected

Effusion from damaged lymphatic vessel or 2ndary to inc hydraulic psi in cranial or CVC

Chylothorax more common in cats (cardiac disease, neoplasia, trauma, idiopathic)

Chyloabdomen rare

Body cavity effusions

Lymphorrhage - Chylous effusion

Colour, Protein, MS?

Body cavity effusions

Lymphorrhage - Chylous effusion

Unique chemical characteristics in chyle?

What tests are done?

Criteria for DX?

Effusion is high in triglyceride & low in cholesterol

Biochemical test on effusion & blood

• Triglycerides

• Cholesterol

What is this? Describe why

Small lymphocytes predominate (left picture), macrophages (middle picture), foamy macrophages (left picture)

Latter neutrophils as effusion is irritant

Body cavity effusions

Lymphorrhage - Non-chylous effusion

Features (general)

(other lymphatics, not triglyceride rich lymph just high in lymphocytes)

(lymphatics not in the drainage path from intestine to thoracic duct)

Body cavity effusions

Rupture of hollow organ or viscous (e.g. bladder or biliary tract)

Indications? Tests for each? Criteria for DX?

Body cavity effusions

What is this? Why?

Lymphorrage - Chylous effusion

Opaque/white- pink (typical)

Exudative effusion – FIP (exception)

Ratio aspect?

Exudative effusion - FIP Exception

Colour/opacity?

Total protein?

Nucelated cells?

MS fx?

Exudative effusion - Sterile or Septic versions

Colour/opacity?

Total protein?

Nucelated cells?

MS fx?

Body cavity effusions

Transudate

Sub classes?

Pathogenesis?

Body cavity effusions

Exudate

Sub classes?

Pathogenesis?

Body cavity effusions

Lymphorrhage and haemorrage

Sub classes?

Pathogenesis?

Body cavity effusions

Transudate low protein & Transudate high protein effusions

The fluid that leaks from the vessels depends on the blood vessels X?

(Previous X) is an indication of X?

This can be roughly determined by?

Body cavity effusions

Transudate low protein & Transudate high protein effusions

Common causes for each?

Normal lymph node morphological features

Look at the arrows, features for each?

90% small well differentiated lymphocytes (grey arrow)

10% of nucleated cells are composed of medium sized lymphocytes (red arrow) scant large lymphoblast (black arrow)

Normal lymph node morphological features

Lymphocyte Types and Features?

lymph node morphological features

What are the red arrows?

Lymphoglandular bodies – basophilic cytoplasmic fragments of lymphocytes (red arrow)

lymph node morphological features

What is this?

Tingible body macrophages – contain phagocytosed apoptotic lymphocytes