PetCancerVet

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CASE HISTORIES

Renal lymphoma

An elderly cat was presented, off his food, drinking a lot and losing weight. His kidneys were 3 times normal size. Ultrasound scan showed generalised enlargement of the kidneys and FNAB showed lymphocytes. Blood tests showed that he still had adequate kidney function.

He was treated with Cyclophosphamide, Vincristine, Methotrexate and Dexamethasone weekly. He regained his appetite within 2 days and his kidneys returned to normal size within 2 weeks. His treatment was continued for 3 cycles of 4 weeks with 4 week gaps and he coped well.

After he finished his 3rd cycle, he was monitored and remained well, with no treatment for 6 months. The problem then recurred but the owners didn't want to give him chemotherapy again so he was given cortisone. The kidneys reduced in size again and he is currently receiving the cortisone.

Bladder Carcinoma

The patient was a 7 year old Bearded Collie bitch. She presented with haematuria and the presence of a bladder tumour was rapidly demonstrated on ultrasonography.
As it was clearly in the cranial pole, a partial cystectomy was performed. Histopathology showed a Transitional Cell Carcinoma.

The prognosis for this tumour is poor. Adjuvant chemotherapy was given, consisting of Methotrexate, Cyclophosphamide and Prednisolone for 6 cycles of one month on/one month off. There were no significant side-effects, and the dog was fit and active throughout.

The dog lived 6 years before being put to sleep with unrelated problems but with no evidence of tumour related disease.

Thyroid Carcinoma

This 12 year old Labrador was well except for her large thyroid mass. It was removed surgically, but there was no chance of getting any surgical margin. Histopathology confirmed a Thyroid Adenocarcinoma.

Adjuvant chemotherapy was indicated as the risk of local recurrence and of metastasis were both high. She received Methotrexate, Cyclophosphamide and Prednisolone for 6 cycles of one month on/one month off. She had mild gastrointestinal side-effects at one stage, but these were easily alleviated and dose modification prevented a repetition.

The dog was put to sleep for unrelated reasons two and a half years later. There was no evidence of tumour.

Nasal Adenocarcinoma

This 10 year old male labrador had a 2 month history of nasal irritation, discharge, sneezing and recent slight epistaxis. X-rays showed a typical soft tissue mass with loss of turbinate detail.

A rhinotomy was performed and the affected nasal chamber cleared. The tissue submitted for histopathology showed an Adenocarcinoma. These tumours have a high metastasis rate so adjuvant chemotherapy was given.

Methotrexate, Cyclophosphamide and Prednisolone for 6 cycles of one month on/one month off caused some bouts of diarrhoea, but these were tolerable. The dog then enjoyed 2 years of normal active life before developing a pancreatic carcinoma for which he was put to sleep. There were no signs to relate to the nasal carcinoma.

Mastocytoma

This was a sad case: delightful dog and owner but poor outcome. I hope that now, with more detailed staging, I could at least predict the problems.

She was an 8 year old Golden Retriever and had developed a soft mass in the right sublumbar region: a 'typical lipoma'. FNAB yielded well differentiated mast cells.

A wide margin was removed at surgery and the entire excised material was sent for histopathology and for checking margins. The results were very encouraging: well differentiated mastocytoma with wide clear margins. The surgical wound healed reasonably well, a small area of breakdown by second intention.

Two months later there were 3 small nodules along the scar line! FNAB yielded well differentiated mast cells. I began to make arrangements for referral to a specialist oncological surgeon with reconstructive expertise, but the dog became ill. She was semi-collapsed with abdominal swelling. This was clearly due to splenomegaly. FNAB of the spleen yielded well differentiated mast cells, and a few were found on a buffy smear.

Chemotherapy with Vinblastine and Prednisolone combined with Cimetidine to protect her gastric mucosa was begun. There was no noticeable response and the dog was put to sleep.

Four months later I discovered and obtained an AgNOR stain kit. I obtained sections from the tumour from the lab and stained them. This showed an average AgNOR count of 4.5. Published data shows that a count over 3.5 is highly suggestive of high malignant potential.

Grading of Mastocytomas is fraught with problems. AgNOR staining adds an extra level of accuracy.

Lingual squamous cell carcinoma in a cat

This cat was one of a series I have treated. The critical aspect is that this was a very early case: many of these cats had significant invasion of the tongue muscle and successful tumour destruction led to scarring and shrinkage of the tongue which then became immobile.

The cat was 13 years old and had been salivating for 3 days when first presented.

The lesion under the tongue was biopsied and impression smears taken which showed typical SCC (confirmed on histopathology). Treatment was begun immediately with 2 drugs: Bleomycin and Methotrexate. Cortisone was given by injection to relieve the pain of the lesion rapidly.

Ten days from the beginning of treatment the cat was eating normally and the tumour had regressed 75%.

Treatment was continued for 3 months by which time the tumour had shrunk to a 3mm nodule. This was removed surgically and chemotherapy continued. Sadly the cat disappeared and was found a few days later dead from major injuries, presumably from a road accident.

The treatment had caused no side-effects and we were starting to hope for a prolonged remission.