Cytology of neoplasia

tissue cell type

There are three basic cell types which may be seen in neoplasia,

(1) round cells-round, individual and discrete.

(2) epithelial cells--usually angular to polygonal (it may depend on their exact type) and often have tight junctions between cells.

(3) spindle cells --individual, or occasionally clustered, and may be spindle, caudate, or stellate in appearance.

nature of neoplasm

It is important for your patient to determine if the neoplasia is benign or malignant. This will have significant implications on prognosis.

‘nature’ of neoplasm

Anisocytosis and Anisokaryosis-> Pleiomorphism

» Anisocytosis is variable cell size

» Anisokaryosis is variable nuclear size

» Pleiomorphism is cell variability – which may encompass a range of changes

• For the majority of mature tissues there is usually little variation in the cells

(Exceptions)

• Granulation tissue

• Lymphoid tissue

• Mesothelial cells

nuclear atypia

» Anisokaryosis- variation in nuclear size

» Multinucleation – dividing cells may have two nuclei (or four in certain cell lineages) for specific stages of cell division.

• But uneven numbers of nuclei indicate errors in cell division/replication

• (Exceptions macrophages, mesothelial cells ?)

» Nucleoli

• Prominent

• Multiple

• Large (approaching red cell size)

• Atypical shape (not round)

» Mitotic figures

» Lagging chromosomes

» Cytophagia- ‘cell cannibalism’

» Karyomegaly (large nucleus)

» Nuclear moulding (nuclear shape appears to adapt around another nucleus)

Cytoplasmic inclusions, Perinuclear vacuolation and Cell cannibalism

benign neoplasms

benign neoplasms

malignant neoplasms

round cell tumours

round cell tumours-lymphoma

epithelial tumour - acinus and tubule

» This gives an overview of how to construct a basic concept map of skin

neoplasia in the dog.

» You may like to add in more facts that you obtain from your reading, or

construct it in a totally different manner that makes more sense to you.

» You may like to consider whether this would look different for the cat, eg would

the mast cell tumour be closer to the benign or malignant area of the map

when looking at cutaneous masses.

» You may also like to think how this might look different for the horse

5Y FN Boxer- small raised skin lesion

2Y ME Springer Spaniel- swelling between digits- right fore

9Y ME Boxer- perianal raised mass

9Y ME Boxer- perianal raised mass

5Y MN Labrador – small thoracic mass