Introduction

Lymphoma is generally defined as a cancer of lymphocytes, which are a type of white blood cell that is present throughout the entire body. Lymphoma usually arises from lymphoid tissues such as the spleen, lymph nodes and bone marrow, but can arise from almost any tissue in the body. It is one of the most common forms of cancer in felines and is the most common tumor type found in the feline gastrointestinal (GI) tract.

Feline GI lymphoma can be categorized as one of three types based on histopathology and immunohistopathology findings. The three types of feline GI lymphoma include low-grade alimentary (LGAL), intermediate or high-grade alimentary (I/HGAL), and large granular lymphoma (LGL).

Felines with large cell GI lymphoma (HGAL) often present with non-specific GI signs and weight loss that have acutely progressed. They are more likely to present with a palpable abdominal mass, enlarged mesenteric lymph nodes or liver than those with LGAL. Icterus also more commonly coincides with large cell GI lymphomas. They are often diagnosed via abdominal imaging and cytology from an abdominal/mesenteric lymph node or lesion found in the GI tract.

The prognosis for felines with HGAL is, unfortunately, poor. The disease is very aggressive and is often difficult to treat. Even with aggressive chemotherapy, only about 30% of felines respond and typically have an average survival time of two to three months. There is a very small percentage of felines who completely respond to chemotherapy and can survive for close to a year.

Case History

Guido, a 15-year-old neutered male Bengal feline was presented to the ISU Emergency service for progressive lethargy, anorexia, and weight loss. He was 5% dehydrated and anemic with a hematocrit of 24% on presentation. An abdominal ultrasound revealed a 3 cm jejunal thickening and multiple enlarged mesenteric lymph nodes. Due to the vascular nature of the intestinal lesion, fine needle aspirates were taken of the regional lymph nodes. The results were suggestive of large cell lymphoma.

Treatment Methods

Guido received a blood transfusion due to his anemia. The purpose of the transfusion was to better perfuse and oxygenate his tissues, which would hopefully improve his clinical condition. His anemia was most likely due to blood loss via the intestinal wall mass found on abdominal ultrasound.

An esophageal feeding tube was placed under general anesthesia. This was recommended due to his hyporexia, and to offset the breakdown of muscle and fat at a higher than normal rate that occurs when a patient has cancer. His feeding tube remained in place for the entirety of his treatment and remission and allowed his owner to be actively involved in his care. She was able to medicate, hydrate and feed him via the esophagostomy tube when necessary.

Surgical excision of the intestinal lesion was discussed to achieve a definitive diagnosis. Although his risk of GI perforation was significant, surgical removal of the lesion was declined.

Guido was started on a CHOP chemotherapy protocol. He was treated weekly for 3 weeks with Vincristine (week 1), Cyclophosphamide (week 2), and Doxorubicin (week 3) followed by a one-week break. This cycle was completed 6 times for a total of 24 weeks of treatment and appropriate treatment delays/substitutions as needed for expected toxicity. Guido was switched from Doxorubicin to Mitoxantrone during the course of his treatment due to progressive kidney disease. In felines, Doxorubicin can cause a cumulative nephrotoxicity, unlike canines, who can experience cardiotoxicity, and should be used with caution when feline patients have underlying renal disease. Mitoxantrone is much less nephrotoxic to felines and can be a reasonable alternative when Doxorubicin is contraindicated.

An abdominal ultrasound was performed on the day of his last chemotherapy treatment, and he was found to be in remission at that time. After receiving his final dose of Mitoxantrone, a long term recheck plan was made, and Guido continued to receive recheck abdominal ultrasounds every month to look for evidence of disease progression. He also received routine blood work evaluations to monitor his anemia and kidney disease. During his treatment and remission, he received multiple blood transfusions due to progressive non-regenerative anemia of undetermined etiology after extensive diagnostics.

Results and Outcomes

Guido’s remission lasted for 17 months after finishing his full CHOP chemotherapy protocol. He defied the odds and outlived even the smallest percentage of felines by five months. During the course of his treatment and remission, Guido battled multiple co-morbidities that we, as his medical team were challenged to balance. These co-morbidities included renal disease, glaucoma, cardiac disease, non-regenerative anemia, demodex, and seizures. He was humanely euthanized a year and a half after his initial diagnosis due to clinical decline and suspected progression of his lymphoma.

Moving Forward

Guido has been a very influential patient during my career in Oncology. Moving forward, I will always be an advocate for esophagostomy tubes in my feline lymphoma patients. As we all know, felines can be tricky to treat and medicate. I truly learned the value of a feeding tube with Guido and I feel that it should be standard of care for our feline patients going through chemotherapy. It not only makes it easier to provide them with essential nutrients during chemotherapy, but it increases their quality of life and allows their owners to take an active role in their treatment.

In addition, I would also advocate for venous access port placement in felines receiving multiple rounds of chemotherapy. Guido did not have a port during his treatment, and it was the most stressful part of his care for both of us. His veins were unforgiving and there were days when IV catheters were not able to be placed safely and treatment was delayed. Often times, the prognosis for felines with lymphoma is poor, so placing a port is not seen as the most cost-effective procedure when weighing it against expected survival times.

References

1.  Vail DM, Thamm D, Liptak, J. Withrow and MacEwen’s Small Animal Clinical Oncology. E-Book. 6th ed. Elsevier Health Sciences; 2019.

2.  O’Keefe DA, Sisson DD, Gelberg HB, et al. Systemic toxicity associated with doxorubicin administration in cats. J Vet Intern Med. 1993;7:309–317.