Page 582 - The Veterinary Laboratory and Field Manual 3rd Edition

Necropsy guidelines 519

remains stable for up to 48 h post-mortem. This • Shape: keep it simple: round, oval, irregu-
can be particularly useful if investigating suspect lar, smooth, papilliferous, nodular, fusiform,
fatal calcium or magnesium deficiency in cattle. reniform, flat, miliary and so on.
The aqueous humour should be collected via • Colour: again, keep it simple: red, brown,
needle and syringe and stored in a plain blood green, yellow. Reserve using ‘black’ for obvi-
tube prior to laboratory analysis. ously melanocytic lesions and ’white’ for
bone or mineralized tissue. If something is
very pale but not mineralized use ‘tan’ or
Excretion
‘off-white’.
Many toxins are excreted in the urine. Fresh kid- • Consistency: simple. Again. Soft, firm, hard.
ney and urine samples should always be retained As an example, forehead is hard, tip of nose
in these cases. is firm, and lips are soft.
• Location: be as accurate anatomically as you
can to describe where abouts in an organ or
A2.7 description of findings tissue the lesion is located.
• Number: if lesions are multiple count them
It is beyond the scope of this chapter to cover up to ten. After that use ‘tens’, ‘hundreds’,
in detail how to describe and interpret lesions. ‘thousands’ to give a more accurate picture
However, it is useful to have some idea as to rather than using ‘few’ or ‘many’.
how to describe lesions and begin to broadly • Inflammation: in life inflammation is char-
categorize them according to the most likely acterized by an increase in blood flow to an
underlying pathogenesis. It is also useful to be affected tissue (reddening), increase in vascu-
able to systematically and logically describe the lar permeability (oedema), leading to outflow
gross appearance of a lesion for several reasons. of plasma proteins (fibrin) and inflammatory
First, you may simply be looking for the input cells. All of these changes persist after death
and advice of a more experienced pathologist and can be used to detect an inflammatory
and need to describe the lesion in question accu- process in an organ.
rately and concisely to them. Second, by going • Acute: the prime hallmark of acute inflam-
through the process of forming an accurate mation post-mortem is the presence of
description it can aid the prosector in interpret- fibrin. Fibrin is a polymerized plasma pro-
ing and understanding a lesion. tein produced during blood clotting and the
Descriptions of each lesion should be in the acute inflammatory response. It often forms
follow terms. strands of soft, tan, friable material but in
less abundant quantities can impart a sub-
• Size: if a lesion is focal or focally extensive tle rough texture to the surface of affected
(for example, a mass within an organ) it organs (Figures A2.5 and A2.6). Affected tis-
should be measured as accurately as pos- sues may also seem reddened or swollen with
sible using metric units. If a lesion is diffuse an excessive amount of fluid exuding from
it can be useful to weigh the affected organ. the cut section.
If the lesion comprises a change in colour • Chronic: Fibrosis is the hallmark of chronic
or texture of the surface of an organ or a inflammation and should be considered if
mucosal surface, giving an estimate of per- an organ or tissue is shrunken and firm. In
centage of the total area affected can be very addition, inflammatory mass lesions such
useful. as abscesses (a fibrous capsule filled with

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