The Abdomen
Ken Wyatt FACVSc
Zoe Lenard FACVSc
Nola Lester DipACVR
Tim Caporn FACVSc
Diagnosis and Therapy
When is surgical exploration indicated?
– curative intent surgery
– diagnostics on multiple lesions or multiple
biopsies from diffuse lesions
Diagnostics
FNA
Needle core
Endoscopic biopsy
Surgical incisional biopsy
Excisional biopsy
FNA
Rule out round cells
– Inflammation
– Lymphoma and related diseases
– Mast cell tumour
– HS, nephroblastoma
Rule in tentative diagnosis
Best when cell type is atypical for location
May seed ovarian and bladder tumours
Felix
4 year old domestic short hair
10 day history of lethargy and decreased
appetite
Both kidneys are markedly enlarged and
knobbly
CBC, chemistry, U/A = renal azotaemia
Ultrasound = no other organs involved
Felix
DDx:
– Lymphoma
– Carcinoma
– Other neoplasia, especially Nephroblastoma
– Amyloidosis
– Glomerulonephritis
Felix
Lymphoma is most likely
Both kidneys are not resectable!
Best approach:
– Either
FNA to diagnose lymphoma (round cell and
tentative diagnosis and wrong cell type for organ),
then needle core if not adequate, or
Needle core
Needle core
Seeds tumour so best for:
– Non-resectable disease
Good for tumour type, less so for grade
Poor for non-neoplastic liver disease
Endoscopic biopsy
GI disease:
– Diffuse
– High, or low location
– Superficial
Unable to differentiate IBD & lymphoma
Good for differentiating different processes
– E.g IBS vs IBD
Incisional biopsy
Safer than needle core re haemorrhage
control
Large sample more diagnostic
Best use: classic exploratory laparotomy
for multifocal organ signs
Coco
10 year old retriever cross
3 months of borborygmus and flatulence
Occasional diarrhoea
Diffusely thickened intestine on ultrasound
Rapidly declining PCV
Giardia RIM positive
Coco
DDx: inflammatory vs neoplastic
Inflammatory
– ‘just’ Giardia
– IBD
– Allergic
– Immune
Neoplastic
– Lymphoma
– Carcinoma
Coco
Not surgically resectable
Rapidly declining PCV forces an urgent
complete diagnosis
Main differentials are neoplastic vs non-
neoplastic lymphocytes
Tissue architecture needed to differentiate
Exploratory laparotomy
– Diagnosis = Giardia
Excisional biopsy
Best when curative intent surgery is clearly
necessary prior to a diagnosis
E.g. large splenic mass
– With normal CBC & abdominal ultrasound
FNA Needle core Endoscopy Incisional Excisional
GI R/O Non- Diffuse Single mass
lymphoma neoplastic
Liver R/O Multi-focal Diffuse Single mass
lymphoma
Kidney R/O Bilateral Single mass
lymphoma
Spleen Small, Single mass
multiple,
diffuse
Bladder Typical TCC Resectable
location
Nodes Metastatic Improve
stage
Adrenal Refer
Relate signs to disease
Once a diagnosis is made:
– Are the signs explained by the diagnosis
– If not, is the disease incidental?
Jonathon
Grade II mast cell tumour removed
completely from the ventral abdomen
Routine staging was done
– Ultrasound of the abdomen revealed a
thickened area in the trigone of the bladder
– BTA test positive
Jonathon
Important points
– No signs of lower urinary tract disease
– The BTA test is unreliable
– Degree of contraction of the bladder can
cause wall irregularities
Jonathon
Most likely – he does not have a bladder
tumour
Plan
– The owner closely monitors for signs of
urinary tract disease
– Ultrasound is repeated 1 month later and no
‘mass’ is seen.
Jonathon
Alternative and appropriate plans
– Immediate cystoscopy or surgery
– Immediately repeat the ultrasound
Specialist
Inflate the bladder if uncertain
Choice depends on the ‘situation’, the
owner, the dog.
Is the mass resectable?
Mobility
– E.g. splenic tumour
Imaging
– Radiographs of limited use
– Ultrasound
Good to rule OUT metastatic disease
Useful at ruling out surgery
– Unreliable at ruling IN
– CT and MRI
Superior over all other techniques
Imaging dilemmas
Why should I bother with abdominal
radiographs these days? Can’t you just tell
everything from ultrasound?
We can miss pathology without radiographs!
Ultrasound requires preparation
Spinal disease