CPD ACCREDITED ARTICLE
8. The pathologist usually lacks corroborative data.
9. The clinician will believe the diagnosis is accurate
and act on it.
10. The patient is still alive, so the diagnosis better be
correct.
The World of Veterinary Oncology
Clinicians and pathologists inhabit very different parts
of the oncology world and have become isolated from
one another geographically as well as scientifically.
Such barriers need to be broken down to achieve the
best possible outcome for patients and this requires
careful, timely and accurate communication among
all the parties involved in the biopsy process. This
breakdown in communication accounts for most of
the problems, mistakes and complaints.
The objective of the biopsy
The objective is to obtain a sample of tissue from a living
patient to identify or characterize a neoplastic process.
The surgeon or clinician is involved in the decision to
biopsy, the sampling of the tissue, preparation of the
tissue and submission of the samples to the laboratory.
The pathologist and the laboratory team continue the
process, create the microscopic slides, evaluate the
specimens and communicate the information back to
the clinician.
New and minimally invasive techniques are being
applied in surgical pathology and to justify the cost of
these techniques, one must maximise the diagnostic
and therapeutic yields from the procedure. As a result,
clinicians are wanting more useful information from
each sample and with the trend toward smaller and
smaller pieces of tissue, increases the pressure for
an accurate diagnosis on the first samples submitted.
With the cost involved with these new procedures it is
unlikely that a second biopsy would be an option if the
first one did not yield a useful diagnosis.
Total patient evaluation
Clinicians practice the principle of total patient
evaluation when making judgments about diagnosis
and treatment. They consider all of the data and
facts at hand in reaching their conclusions. Likewise,
pathologists should not base their diagnosis just on
what they see on the slide. Unfortunately, in many
scenarios none of the data facts are provided to
the pathologists and all that they are left with is a
slide to evaluate in isolation. Pathologists should
describe what they see in the biopsy but make a final
interpretation or diagnosis in context of all the relevant
information about the case. This ability for pathologists
to perform a total patient evaluation depends almost
entirely on the clinician.
•
Total patient evaluation for pathologists: read a
slide but interpret a patient.
•
Total patient evaluation for clinicians: give the
pathologists what they need to make a patient
interpretation.
Outcomes of the biopsy procedure
• Best outcome: rapid, accurate diagnosis of a
specific neoplasia and timely application of
appropriate therapy.
• Worst outcome: no diagnosis made and therapy
is delayed or inappropriate.
• The middle route: a partial diagnosis is made
but does not translate into a specific entity. The
non-specific nature does not meet the clinicians
expectations or the patient’s requirements.
The particular outcome category depends largely on
total patient evaluation information being provided
pathologist.
Getting a diagnostic biopsy
This remains the most important task of the clinician
in his workup of the tumour case. So, what constitutes
a diagnostic biopsy?
1. Adequate amount of tissue.
2. Representative of the neoplastic process.
3. Sufficiently free of artefacts to permit a definitive
evaluation.
4. Signalment, history, description of the lesion.
5. The clinicians differential diagnoses, rule out’s,
thoughts.
Adequate amount of tissu e
Clinicians had a wide array of techniques at their
disposable with which to obtain surgical biopsies for
tumour diagnosis. Pathologists should never question
first technique used by the clinician, as this is often a
1st rule of medicine (do no harm) decision. However,
clinicians should be fully aware of the limitations and
potential problems associated with their choice of
biopsy technique.
A) Fine needle aspirates
• Advantage: easy,
inexpensive.
minimally
• Use: when significant conclusions can be drawn
by evaluating individual dissociated cells and
is largely employed to distinguish between
inflammation and neoplasia.
• Disadvantage: it is extremely limited as no
architectural detail can be examined.
Issue 04 | SEPTEMBER 2018 | 5
invasive
and