1. University of Cambridge
Evaluation of the necessity of clinical staging in Mast Cell Tumors (MCT): A retrostective study on a referral population of 237 dogs ( )
Isabel Amores – Fuster MRCVS
William Newbury MRCVS
Dr Jane M Dobson DECVIM MRCVS

2. Introduction
Canine Cutaneous Mast Cell Tumors: Variable behaviour and metastatic potential.
Traditionally a full clinical staging is recommended:
CBC and biochemistry
Thoracic and abdominal radiographs
Abdominal ultrasound (Liver and spleen)
FNA of the loco-regional lymph nodes
Bone marrow biopsy…

3. Hypotesis
Canine Cutaneous Mast Cell Tumors always metastasize to the loco-regional lymph nodes before they spread to other organs.
So… full clinical staging will not be necessary if there are no evidences of metastasis to the loco-regional lymph nodes.

4. Material and Methods
237 dogs with cutaneous MCT referred to QVSH (Cambridge) between 1998 and 2008.
Full clinical staging:
FNA of palpable loco-regional lymph nodes
Thoracic radiographs
Abdominal ultrasound
CBC and biochemistry
Follow up: Telephonic interviews with referring vets and owners.

5. Population data
Breed: Labrador (31%), Golden Retriever (12.8%), Boxer (9.8%), SBT (7.2%).
Age: Mean age at presentation 7.4 years
Sex: 102 males and 132 females. No significant differences between sexes.

6. Of 237 cases… 142  Complete clinical staging and follow up.
29  Complete clinical staging but partial follow up.
20  Complete clinical staging no follow up.
39  Incomplete clinical staging or relevant history. Excluded.

7. Tumor grade Diagnose  Histological or cytological findings.
23 cases grade I.
154 cases grade II.
20 cases grade III.
8 cases  Multiple tumors on presentation.
22 cases  Only by cytology.
7 cases  disagreement between pathologists.

8. Tumor grade

9. Metastasis 69 cases  LN involvement (29.2%)
16 cases  LN and distant metastasis (6.2%)
1 case  Distant metastasis but no LN (0.4%)
105 cases  No metastasis (64.2%)

10. Metastasis (cont) 6 cases  Grade I 42 cases  Grade II
11 cases  Grade III
The rest  Cytology or disagreement in the grade.

11. Discussion Age, breed and sex results consistent with literature.
All dogs with distant metastasis also had LN involvement but one.
This case had clinical and radiographic findings consistent with a concurrent pulmonary neoplasia.

12. Conclusion
FNA of the loco regional LN should be performed in all cutaneous MCT cases.
Further clinical staging in absence of LN involvement ????
Unless there are other clinical signs or a possible treatment that justify it.

13. Aknowledgements Jane Dobson, Malcolm Brearley & Frances Taylor
The owners and referring vets that participate in the study

14. Any questions?