TV4101 - Cytology 1

Cytology Pros?

Quick
Atraumatic

Cheap

No anaesthetic

Well tolerated mostly

Cytology Cons?

Screening - may need furhter tests

Suscept to sample bias

May be inconclusive due to low cellularity or artefacts

Unable to evaluate tissue architecture

Cytological criteria of malignancy overlap with

dysplasia

Types of Tissue Cells
Which is which?

Left - Round cells

Middle - Epithelial Cells

Right - Mesenchymal Cells

Types of Tissue Cells - Round cells

Describe shape?

Cellularity of slides?

Distribution on slide?

Round

Well defined border

High cellularity

Distribution: Exfoliate individually, evenly across slides

Types of Tissue Cells - Epithelial Cells

Features?

Cellularity of slides?

Distribution on slide?

Polygonal to cuboidal or columnar

Usually distinct cell borders/margins

High cellularity

Distribution

• In clusters or sheets

• Some adherenace btw cells

• Malignant cells may lose adhesion

Types of Tissue Cells - Mesenchymal Cells

Shape?

Borders?

Cellularity?

Fusiform, spindle or oval to stellate (some may be more plump and round e.g. cells from bone) '

Cell borders may be indistinct or wispy cytoplasmic tails

Cellularity: Usually low due to adherence of cell in matrix, but malignant tumours might have a moderate to high yield.

Types of inflam cells

Detailed classification

Morphological Interpretation?

What is this?

Describe the cells

Behaviour?

Histiocytoma (round cells)

Round cells - uniform, lots of cytoplasma that is clear, fine chromatin pattern, round nucleus (Like fried eggs)

Benign and respond spontaneously (If not gone in 2 months or inc and dec in size → is not histio but mast cell tumour_

What is this?

Describe the cells

What do?

Mast Cell Tumour (MCT) - Round cells

Middle photo - Well granulated with purple granules

Right photo - Agranular version

Have clinically and medically staged and graded - have they got to the local lns (FNA or biopsy)

• Sx removal then ask pathologist for margins and grading

What is this?

Describe the cells

Lymphoma

Round cell, prominent nucleoli

What is this?

Describe the cells

Behaviour?

Plasmacytoma - Round cells

Cells have eccentric nuclei

Course chromatin pattern aka clock face

Very blue cytoplasm

Benign but require Sx removal (generally curative)

• If in BM v bad as causes multiple myeloma

What is this?

Describe the cells

TX?

Transmissible venereal tumour

Round cells - vacuolated

Surgically debulked then tx with vinchrinstine

Round cell tumours - Histiocytoma

Common app?

Single smooth pink raised hairless mass oft on head, pinnae

Round cell tumours - MCT

Common app?

Single/multiple white-light yellow or haemorrgic masses/plaques

Ulcers common

Visceral involvement possible

Round cell tumours - Lymphoma

Common app?

Multi offwhite/red to purple nodules on skin

Round cell tumours - Plasma Cell Tumour

Common app?

Single raised pink nodule on head, trunk or limbs

Round cell tumours - Transmissable veneral tumour

Common app?

Single or more oft multi pedunculated to cauliflower-like masses on ext genits of sexually active dog

Round cell tumours

Cyto charactersitics?

Histiocytoma

• Moderately pale

• Slightly granular cytoplasm

• Round to slight indented nucleus

Mast Cell Tumour

• Purple cytoplasmic granules in pale cytoplasm

Lymphoma

• Slightly blue cytoplasm

• Mitotic figures common (in high grade ones)

• High nucleus-to- cytoplasm (N:C) ratio

• Finely granular chromatin

Plasma cell

• Large round eccentric nucleus

• Abundant blue cytoplasm oft with perinculear clear zone

• Mitotic figures maybe

Venereal Tumour

• Round nuclei

• Moderate amount of pale cytoplasm with few

• Small distinct cytoplasmic vacuoles

• Mitotic figures maybe

Round cells - Which is which?

Top Left - Histiocytoma

Top right - MCT

Middle Left - Lymphoma

Middle Right - Plasma Cell Tumour

Bottom - Transmissable Venereal Tumour

What is this?

Behaviour?

What do?

Sebaceous adenoma/hyperplasia - Sebaceous epith cells

Benign

Sx removal if bothering animal

What is this?

Features?

Trichoblastoma (Basal cell tumour)

Basal eptihelium cells

Pretty uniform

High nucelo to cytoplasmic ratio

What is this?

Features?

Perianal gland hepatoid adenoma - Epithelial cells

Hepatoid as cells mimic hepatocytes

What is this?

Features?

Lipoma (benign) or Liposarcoma (malignant) - Mesenchymal (Spindle) cells

Lipoma most common - Generally don’t have to remove unless issues in locomation or bothersome

Neoplastic mass of adipocytes

What is this?

Features?

Fibrosarcoma (Spindle/Mesenchymal cells)

Spindle cells making fibroid

What is this?

Features?

Haemangiosarcoma (HSA)

Very Malignant

Seen at spleen, liver, heart and skin

What is this?

Features?

Where can it be found commonly in dogs?

Osteosarcoma (Mesenchymal/Spindle cells)

Types of tissue cells - what can we see

Slide not drying due to fat = Lipoma or Liposarcoma

Criteria of malignancy

(predominantly applied to ?)

What broad parts of the cells do we observe and rank which are more important / give more confidence whether mass is benign or not?

Predominantly applied to epithelial & mesenchymal tumours

1. Nucleoli

2. Nuclear

3. Cytoplasmic (be careful of dysplasia)

Criteria of malignancy - Nucleoli

Features that are abnormal?

Description?

Criteria of malignancy - Nucleoli

Describe the cell - malignant or no? Why?

Macrokaryosis

Macronucleoli

Macrocytosis

(Increased nucleolar, nuclear & cell size)

Malignant

Criteria of malignancy - Nucleoli

Describe the cell - malignant or no? Why?

Pleomorphic nucleoli with varying size and shape

Macronucleoli

Angular nucleoli

= malignant neoplasia

Criteria of malignancy - Nucleoli

Describe the cell - malignant or no? Why?

Multiple nucleoli

Anisonucleoliosis

= malignant neoplasia

Criteria of malignancy - Nucleoli

Describe the cell - malignant or no? Why?

Abnormal mitotic figures

Malignant

Criteria of malignancy - Nuclear Features

Includes?

Description?

Criteria of malignancy - Nuclear Features

Describe the cell - malignant or no? Why?

Anisokaryosis = nuclear variation in size

Malignant

Criteria of malignancy - Nuclear Features

Describe the cell - malignant or no? Why?

Multiple nuclei = malignant neoplasia

Criteria of malignancy - Nuclear Features

Describe the cell - malignant or no? Why?

Nuclear molding (hugging nuclei) - Malignant

Criteria of malignancy - Nuclear Features

What are we comparing?

Theory behind it?

Describe each

Nuclear features – chromatin pattern (theory: coarser than usual suggests malignancy)

How do diff tissue cells metastatise?

▪ Round cells & epithelial tumours metastasize via lymphatics

▪ Mesenchymal predominantly metastasize via blood vessels (but occasionally via lymphatics – usually a sign of more aggressive disease)

Types of TIssue cells - the other category