Saturday, September 17, 2011

Cancer Part 2: Lymphoma

In the previous post we discussed lymph nodes as common places for cancer to metastasize to, but there can also be primary cancer of the lymphatic system.  This is known as Lymphoma or may sometimes be called Lymphosarcoma.   Dogs with Lymphoma (LSA) commonly present with the complaint of lumps, swellings or masses around the head and neck.  These are the submandibular and prescapular lymph nodes that the owners are feeling as they pet or groom their dog.  The diagram below shows the locations of the external lymph nodes you can feel in a dog.

Typically, once the veterinarian examines the dog they will find that most or all of the above nodes are enlarged.  There can be two reasons for this 1) systemic illness or infection (remember the lymph nodes clean or drain infection away from the cells) or 2) cancer of the lymph nodes=lymphoma.

Diagnosis can usually be made by cytology/fine needle aspirate but sometimes a surgical biopsy is needed.  Note than most dogs are feeling fine at the time of diagnosis.

This is what a cytology of lymphoma looks like
I tried to find a normal lymph node for comparison but that was harder than anticipated.

Enlargement of the lymph nodes is the most common form of LSA accounting for greater than 80% of cases.  Cutaneous (skin), splenic, intestinal and other extra-nodal forms make up the rest.  Lymphoma is one of the most common canine cancers and occurs in an estimated 24/100,00 dogs annually. 

While LSA typically affects middle aged to older dogs, this disease does not discriminate against age.  I have diagnosed dogs as young as 2-3 years old.  That's really not something you want to do-people do not expect their tail-wagging two-year old dog to be diagnosed with a terminal illness.  Breeds with increased incidence include Boxers, Bassets, St. Bernards, Airedales, and Bulldogs. 

LSA is a rapidly progressive disease.  Without treatment survival times are approximately 1 month.  Treatment options include prednisone, single agent chemotherapy or multi-drug chemotherapy.  Prednisone alone can extend survival to 2-3 months.  This is a very inexpensive option for owners who don't want or are unable to pursue traditional chemotherapy.  Multi drug protocols are the most successful with 60-80%  of dogs obtaining remission. There are a variety of protocols available, many of which involve weekly or twice monthly treatments sometimes with oral medications given daily.  These protocols can involve a significant time and financial commitment on the part of the owner but can achieve survival times of up to 12 months. 

Incidence of feline lymphoma is estimated to be 200/100,000 annually.  Feline lymphoma is not typically limited to the nodes but can include internal organs, intestines, blood and bone marrow.  A significant amount of cats with lymphoma are Feline Leukemia positive.  Radiation therapy is appropriate for certain forms of lymphoma with multi drug chemo protocols being used for the rest.  Remission rates are approximately 60% with an average 40 week survival time.


Kathy said...

wow, that makes it all sound pretty straight forward and easy to understand. Is it heriditary- Does it run in certain lines more often if it affects certain breeds more?

Nicki said...

While the fact that certain breeds are predisposed indicates at least a partial genetic link I don't know if it runs more in certain lines.

Paulette said...

Two sibling female Golden Labs (yellow lab/golden retriever mix) reg. vet exams, no indication of illness. Born 2011 (our #4 & #5 large dogs). Several months ago, one dog began horse choking after eating; diagnosis: "reverse sneezing." Worsened & rear legs weak; vet recommended neurologist. Following exam, consult, decided needle aspiration of mass found in chest x-ray. Lymphoma suspected. We asked for MRI aware of expense to confirm severity. Our gentle beautiful pup diagnosed last week with lymphoma. Survival 2-3 months taking daily prednisone, 2-3weeks on no meds. Surgery not possible, tumors chest & spine visible on MRI. Prednisone causing lethargy, incontinence. Healthy sibling has lost her playmate, sad to watch. Lost our beloved 130 lb. Shepard 2011 @ 13 1/2 yrs.& pray for a peaceful ending for our young Siena. We are heartbroken but can only hope there truly is a "Rainbow Bridge."

Anonymous said...

My 3 year old Boston Terrier actually just got diagnosed with lymphoma today, all his lymph nodes are swollen. The doctor prescribed prednisone and we are going back in a week to see if he feels better. He has had these swollen lymph nodes for about 4 months now. What are the chances that he'll make it?

Anonymous said...

Hi I'm so sorry this is late but 4 days ago my beautiful 2 year old dogue de Bordeaux was diagnosed with lymphoma. We took her in on the 23rd of December and they prescribed anti biotics after 3 weeks lympnodes were still swollen..a biopsy was taken after a huge, hard, hot lump in between her legs came up after that she became in severe pain and prescribed tramadol. 7 days later we were called in for the results which devastated us to find out she had the late stages of lymphoma and without treatment would survive only 1-2 months. The pain got so worse for her she could not walk and was yelping in pain through the night, 3 days later after diagnoses we had to make the decision to have her put to sleep to stop her pain as it would have only been the beginning and I couldn't let her go through any more suffering she didn't deserve it, I feel for every one who has had to deal with this as it is absolutely heart breaking, I still can't believe my baby was taken away at 2 years old. Let's all hope there is some peace for them now and I hope she is always with me.