Chemotherapy at CFVC

A 6 year old female-spayed Collie presented to me in September of 2013 with a growth in the mouth, right out in front of the left incisors. It didn’t respond to initial antibiotic and anti-inflammatory therapy, so surgery was scheduled to get a biopsy.

Leigh-LeighAcanthamatous ameloblastoma

The result: Acanthamatous amelobastoma

From IDEXX Laboratories:

Oral mucosa: The submucosa is expanded by an unencapsulated, invasive mass composed of anastomosing cords and broad sheets of polygonal cells and a prominent peripheral layer of palisading columnar cells within a minimal fibrovascular stroma. Neoplastic cells have distinct cell borders, abundant eosinophilic cytoplasm, and prominent intercellular bridging. There is mild anisocytosis and anisokaryosis. Nuclei are round to oval with vesicular chromatin. Lesional tissue extends to the apparent deep margin of the submitted specimen.

Acanthomatous ameloblastoma (acanthomatous epulis) has an aggressive local behavior and frequently invades the bone of the underlying mandible or maxilla. Golden Retrievers, Akitas, Cocker Spaniels, Shetland Sheepdogs, and Old English Sheepdogs are predisposed. The mean age at presentation is 7-10 years, and sex predisposition is unlikely. The rostral mandible is the most common site. They do not metastasize.

At the time, we spoke about rechecking in 4 to 6 weeks. It did, in fact, return and it was angry. Her owner brought a study to my attention using a chemotherapy drug called Bleomycin. As I’m not an oncologist, and I rarely get into advanced chemotherapy beyond prednisone for Lymphoma, this treatment was news to me, and I happily read the study. The survival times looked encouraging, but when I got to the part about adverse effects, I thought some of them were a little startling.

Adverse effects were limited to wound formation with bone exposure (n = 4), mild tissue reactions (n = 3), local swelling (n = 2) and local infection (n = 1)

The small sample size was also noteworthy. Not much is known about how this form of cancer responds to treatment… any treatment or combination of treatments.

After a conversation with the owner, and some thought on his part, he decided to move forward. We committed to 6 weekly treatments. The anesthetic protocol and Bleomycin administration protocol was strictly followed, we needed to reach for antibiotics on some occasions, and we stayed the course for 6 treatments. Follow the progression of photographs below.


January 24, 2014:
Acanthamatous ameloblastomaAcanthamatous ameloblastoma
January 31, 2014:
Acanthamatous ameloblastomaAcanthamatous ameloblastomaFebruary 7, 2014:
Acanthamatous ameloblastoma

February 14, 2014:
Acanthamatous ameloblastomaAcanthamatous ameloblastoma

February 21, 2014:
Acanthamatous ameloblastomaAcanthamatous ameloblastoma

February 28, 2014:

Acanthamatous ameloblastomaAcanthamatous ameloblastoma
Acanthamatous ameloblastoma

 

I was very pleased with the relative lack of horizontal bone loss. It took only a short time for the ulcer to heal, and at seven weeks, there was some thickness to the surrounding soft tissue, though there is no visual evidence of recurrence.

This dog’s results were very similar to the dogs in the study. This, in the owner’s opinion and my opinion, is a win!

Summary, Before & 7 Weeks Post-Chemotherapy

Acanthamatous ameloblastomaAcanthamatous ameloblastoma

Update: July 8, 2014

Leigh-Leigh

Update: April 10, 2015

Acanthamatous ameloblastoma, 14mos post

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