cytology of tumours

Indications for cytology

Lesion palp/ on imaging

Organomegaly

Cavity effusion

Staging

Pyrexia of unknown origin

What can cytology tell use

Infl, neoplasia, benign/malignant, type of neo

Sensitivity + specificity of cytology (diagnostic quality slides)

Sen= 75-89%

Spec= 97-100%

Which tumours can be identified with cytology

Lymphoma, MCT, histiocytoma

Advantages of cytology

Non invasive

Cheap

In house

Quick results

DisAdvantages of cytology

Non diagnostic/ representative

No definitive diagnosis

Approach to slide evaluation

Macro - labels, smear

Micro- cellularity, stain, populations, morphology

Causes of Common sample quality issues - unstained smear

Too thick

Dec time

Not dry before staining

Causes of Common sample quality issues - Overstained

Inc staining time

Causes of Common sample quality issues - Ruptured cells

Inc aspiration P

Inc P in smearing

Causes of Common sample quality issues - Cells balled up

Slowly dried

Common artifacts

US gel

Hb crystals

Clot activator

Pollen

Spit

Stain precipitate

Formalin fumes

Infl vs neoplasia

I - infl cells, microorganisms, fibroblasts

N- monomorphic, infl, matrix, necrosis

Causes of infl in neoplasia (commonly SCC, mammary carcinoma, fibrosarcoma, MCT)

Tumour invasion, necrosis, secondary inf, immune response

Types of infl - neutrophilic causes (>85% neutrophils)

Immune mediated, irritants, bact, Protozoa, fungi

Types of infl - histiocytic.macrophagic causes

FB reaction, fungi, bact (mycobacterium)

Types of infl - mixed (neutro+macro) causes

FB reaction, fungal inf, bact (nocardia, actinomyces)

Types of infl - eosinophilia causes (>10% eosinophils)

Hypersensitivity, parasites, fungi, insect bites, cancer

Types of infl - lymphocytic/lymphoplasmacytic causes

Ag stimulation, viral inf, chronic infl

Cytomorphological tumour types

Epithelial

Mesenchymal

Round cell

Naked nu

Benign vs malignant morphology

B- uniform size, defined borders, uniform nu, small nu, even chromatin, norm cytoplasm, low mitotic count

M- pleomorphic, inc nu:cytoplasm, irregular nucleoli, clumped chromatin, atypical cytoplasm, inc mitotic count

Criteria of malignancy

Pleomorphic

High nu:cytoplasm

Anisokaryosis

Coarse chromatin

Nucleoli changes

Multi nu

Abnormal mitosis

Criteria of malignancy - pleomorphism def

Variation in size, shape, maturation of cells + nu

Cells common in MCT

Eosinophils

Criteria of malignancy - Anisokaryosis def

Variation in nu size → high / varied nu:cytoplasm

Criteria of malignancy - Chromatin appearance

Ropy/ clumped

Criteria of malignancy - Why does abnormal nu shape occur

Rapid growth in tight space

Criteria of malignancy - Multi nu can also occur when

Hyperplasia

Criteria of malignancy - Abnormal mitotic figures

Abnormal chromosomes

Epithelial tumours - general cytology

Clumps/sheets

Large round/polygonal cells + distinct borders

Round/oval nu

Epithelial tumours - sebaceous adenoma cytology

Sebocytes + foamy cytoplasm with small dense central nu

Epithelial tumours - perianal/hepatoid gland tumour cytology

Sheets of cells looking like hepatocytes (large oval cell, round nu, 1 nucleolus)

Epithelial tumours - SCC cytology

Large polygonal cells

Pleomorphism

Perinu vacuole

Neutrophilic infl

Epithelial tumours - mammary carcinoma cytology

Sheets/clusters/ acini

Pleomorphism

Norm epi tumour appearance

Basophilic

Mesenchymal tumours - general cytology

Exfoliative individual / in matrix

Oval/ fusiform

In district cytoplasmic border

Long nu

Mesenchymal tumours - soft tissue sarcoma examples

Fibrosarcoma, liposarcoma, leiomyosarcoma, perivascular tumour, rhabdomyosarcoma, peripheral nerve sheath tumours

Mesenchymal tumours - lipoma cytology

Benign adipose

Mesenchymal tumours - osteosarcoma cytology

Round/ spindle cells

Basophilic cytoplasm

Eccentric nu + prominent nucleoli

Osteoclasts

Pink osteoid matrix

Round cell tumours - general cytology

Exfoliate individually

Round

Distinct borders

Round nu

Round cell tumours - examples

TVT, MCT, lymphoma, plasmacytoma

Round cell tumours - histiocytoma cytology

Oval cells + nu

Lightly basophilic cytoplasm

Regressing lesions

Round cell tumours - plasmacytoma cytology

Cutaneous = benign

Mono/pleomorphic

Deep blue cytoplasm, lighter around nu

Round nu

Round cell tumours - lymphoma cytology

Round cells

High nu : cytoplasm

Large monomorphic lymphocytes

Round cell tumours - MCT cytology

Eosinophils

Granular + nu variation

Round cell tumours - MCT common breeds

Boxer, pug, Boston Terrier

Which stain to not use for MCT + why

Diff quik - granules not visible

Endocrine/neuroendocrine tumours - general cytology

Loose sheets

Free nu (naked nu)

Indistinct cytoplasm borders

Round/ polygonal

Round nu

Endocrine/neuroendocrine tumours - thyroid carcinoma cytology

Blood in background

Cell clusters + naked nu

Dark cytoplasm

Colloid

Endocrine/neuroendocrine tumours - pheochromocytoma cytology + effects as from adrenal medulla

Pale blue cytoplasm + naked nu

Catecholamine release

Tumour types - a

Epi

Tumour types - B

Mesenchymal

Tumour types - C

Round cell

Tumour types - d

Endo/ neuroendo

Malignant melanoma features

Variable pigment, infiltrative, ulcers, infl

Pleomorphic, dark granules masking nu/ no granules , large nucleolus