Once-in-a-career case

Last week's rotation was oncology.

The oncology patient I saw with a senior student on Tuesday morning with a senior student was strongly suspected to have lymphangiosarcoma.

Lymphangiosarcoma is a super-rare malignant cancer derived from the endothelial cells that line the lymphatic vessels. The lymphatic system drains excess fluid from the tissues all around the body and helps that fluid get back into the blood vessel circulation where it belongs.

Of the 5 or so veterinary oncologists on the rotation with us students last week, only 1 of them had ever seen another case of lymphangiosarcoma -- and there are only 16 cases of it documented in the veterinary literature.

The patient, "Sunny," was a sweet, medium-sized, portly 6-year-old mutt. She came in from her owners' backyard a few weeks ago with what looked like an abrasion on her hind leg -- which was unusual, because it spanned most of the inner surface of the leg -- a strange place to have gotten a large abrasion without any other obvious trauma.

Over the next few days, the suspected abrasion developed a lot of bruising around it and appeared to spread -- not only on the inner surface of the leg, but up into the inguinal and caudal abdominal tissue as well.

Even though Sunny's regular vet put her on antibiotics for possible infection, her leg just continued to get worse. After a few more days, the vet decided Sunny had a bad case of vasculitis and referred her to the vet school.

Sunny presented to the VTH's Dermatology service a week before she ended up at Oncology. The clinicians in Derm that week agreed that Sunny probably had a very bad case of vasculitis and cellulitis that would just take awhile to resolve. But, they pointed out to Sunny's owners that they couldn't rule out a cancerous process just by the way things looked.

So the dermatologists offered Sunny's owners a biopsy to definitively diagnose the condition that was causing horrible swelling and oozing all up and down her hind leg. Fortunately, Sunny's mom and dad agreed to the procedure, because the biopsy results (taken from 4 different locations on Sunny's leg and inguinal region) showed "angiosarcoma."

"Angiosarcoma is a semi-broad term that can encompass 2 different types of cancer: (1) Hemangiosarcoma, a cancer of the cells that line the blood vessels, or (2) lymphangiosarcoma, cancer of the cells lining the lymphatic vessels. Because both types of vessels are lined by endothelial cells, it can sometimes be difficult to differentiate their origin when you look at a cancerous tissue sample microscopically.

Hemangiosarcoma (HSA) is much more common than lymphangiosarcoma. Actually, HSA is one of the more common types of cancer seen in dogs. However, HSA is usually found in the organs -- the spleen, liver, and heart. It less commonly appears in a skin or subcutaneous form, like what Sunny might have.

But after consulting with all of the experienced oncologists, and reviewing what little information is available in case reports and textbooks pertaining to lymphangiosarcoma, it was felt that that was more likely to be the cancer that poor Sunny was facing.

So what to do for Sunny? Unfortunately, not cure her illness. Her disease had an extremely rapid onset and progression of her disease (over just a couple weeks' time). The inability to differentiate neoplastic lymphatic vessel cells from neoplastic blood vessel cells on her biopsies indicated that the cancer was probably a very progressive form. If it weren't so aggressive, or had been treated within a couple days of appearing, perhaps Sunny could have been treated by amputating her affected leg and hoping the cancer hadn't spread locally or metastasized. But with biopsy samples confirming the spread of disease past her leg and onto her abdomen, amputation couldn't cure her.

This was a really sad case. Sunny's owners were not only faced with a dog who had at best 6 months to live even with the best medical treatment, but also had financial concerns about how they would be able to afford her treatment. Not including the money spent at their referring vet and in Dermatology for her workup and biopsy, they faced a $120 consult fee with Oncology, plus around $170 for thoracic radiographs to check for metastasis to the lungs and $300 for abdominal ultrasound to look for abdominal organ involvement.

One of the toughest things Sunny's mom and dad had to handle was the fact that, from a hygienic point of view, Sunny's quality of life wasn't great. Her affected leg was very swollen and constantly oozed a copious amount of reddish fluid -- to the point that Sunny's mom would apply compresses to her leg multiple times a day and drain out maybe a half cup of fluid, but the leg would fill back up again with the same amount of fluid within 10-15 minutes.

Because of her messy leg, poor Sunny was restricted to certain parts of the house -- the dining room with hard floors, a carpeted section of the house where her owners had laid down plastic sheeting, and the patio and backyard. Sunny wasn't happy being away from her owners, and they weren't happy being apart from her, and not being able to have her sleep in bed with them.

One of the sort of neat treatments that Sunny's owners opted to try with her was some palliative radiation treatment. Radiation therapy can be used in one of two ways: (1) with "curative intent," or (2) to make the animal more comfortable. Radiation can reduce pain and inflammation and also sometimes dries up the irradiated tissue, which the oncologists hoped would help with the constant oozing and dripping from Sunny's leg.

Other than that, there wasn't a whole lot that even my university's renowned animal oncology department could offer Sunny and her family. She was enrolled in a clinical trial for a new chemotherapy drug that she's scheduled to start this week, but nobody was too optimistic about that.

Sunny's case was tough to handle emotionally, but provided some good insight into the type of cases that the oncologists see every day -- or at least every week. They kept telling me that "not all cases are this sad!" but it sure seemed like I just got luck of the draw with the bad ones all week.

My case on Monday was an older miniature Schnauzer who came in because her owners were worried about 7 skin masses. We aspirated 6 of the masses which turned out to be lipomas (benign fatty tumors). The 7th came back as a nerve sheath tumor. However, on physical exam, the oncology resident detected some liver and spleen enlargement during her abdominal palpation. Little Schnauzer headed over to radiology for an ultrasound, and went to emergency surgery just a couple hours later to have her huge, cancerous spleen removed -- later diagnosed as a hemangiosarcoma. It was sort of funny (in a morbid way) that this little dog presented for skin masses, one of which turned out to be bad, but the thing that would have killed her (the splenic tumor) was something the owners and referring vet had no idea about.

My Wednesday case was a sweet little 13 year old terrier mix -- tan in color but shaped and sized like a largish Jack Russell. He showed up at his regular vet about 5 months previously for a mass on his hip. He went on antibiotics and the mass went away; he stopped antibiotics and after a few weeks the mass came back; he had more antibiotics and the mass shrunk but didn't disappear this time. Finally his rDVM did a fine needle aspirate to look at some of the cells from the mass microscopically. As the owner put it, "Dr. RDVM said he had no idea what the cells were and he said that meant we should go to the teaching hospital." Sadly, by the time the little terrier presented to us, he had multiple other masses and enlarged prostatic lymph nodes indicating that his disease had already spread beyond the point of much treatment. He's probably also headed for some palliative radiation, mostly to shrink his sublumbar lymph nodes enough to let him defecate comfortably for as long as possible. At the time I left the case, his mass was suspected to be histiocytic in origin.

After 3 depressing cases (hey, some dogs come in with a leg tumor, get it amputated, and they're all better!), I opted to spend all of Thursday morning hanging out with the radiation technicians in the radiation therapy department. I got to meet some cool patients who were having either intensity-modulated-radiation-therapy (usually treated 5 days a week for 3 or 4 weeks) or stereotactic-radiation-therapy (treated 3 days in a row, then that's it). I got to see the difference between the palliative therapy and the 'curative-intent' treatments. And I got to meet the dog with the huge skull tumor between his eyes who is affectionately referred to by the oncology staff as "our unicorn"!