Case Study

Lymphoma in a 15 year old MN DSH cat

A 15- year-old MN DSH cat was presented with a history of vomiting hairballs and weight loss in three years before this visit. Physical exam at that time was unremarkable. Blood chemistry found hyperphosphatemia, hypercholesterolemia, hypercalcemia, hypernatremia, hyperchloremia, hyperamylasemia, hypermagnesemia, and a high calculated osmolality. CBC revealed leukopenia, neutropenia, lymphopenia, and thrombocytopenia. The urinalysis, and urine microalbumin were all within normal reference range. The T4 was high and methimazole treatment was initiated.

A 15- year-old MN DSH cat was presented with a history of vomiting hairballs and weight loss in three years before this visit. Physical exam at that time was unremarkable. Blood chemistry found hyperphosphatemia, hypercholesterolemia, hypercalcemia, hypernatremia, hyperchloremia, hyperamylasemia, hypermagnesemia, and a high calculated osmolality. CBC revealed leukopenia, neutropenia, lymphopenia, and thrombocytopenia. The urinalysis, and urine microalbumin were all within normal reference range. The T4 was high and methimazole treatment was initiated. However, the weight loss continued over the next 2 years despite treatment with methimazole. Recheck blood chemistry revealed hypoglycemia, and an elevated urea. CBC found thrombocytopenia and lymphopenia. The cat developed an infection of the upper respiratory tract a few months later and radiographs of the thorax (three views) were performed, which did not reveal any obvious masses.

DX

Lymphoma, lymphoblastic (high grade), likely alimentary in origin.

Sonographic Differential Diagnosis

Mesenteric lymphadenopathy or mass. Lymphoma, round cell neoplasia or granulomatous disease. Dry form FIP

Image Interpretation

A dramatically hypoechoic lymph node mass is evident in the mesenteric root. Complete loss of detail is evident with reactive hyperechoic surrounding fat. Mesenteric vasculature is evident on power Doppler assessment. A slight amount of free fluid is noted adjacent to the lymph node consistent with inflammatory fluid or potential transudate owing to lymphatic strangulation.

Outcome

Cytology results were consistent with lymphoblastic (high grade) lymphoma, likely alimentary in origin. The patient was referred to an oncologist and chemotherapy was initiated. A re-evaluation was performed by the rDVM at which time a firm abdominal mass was palpated. A second course of chemotherapy was started. However, the patient did not improve and was humanely euthanized.

Clinical Differential Diagnosis

Gastrointestinal, hepatic or pancreatic neoplasia (lymphoma, adenocarcinoma, leiomyoma, leiomyosarcoma, mast cell tumor); severe inflammatory bowel disease which progressed to lymphoma.