Case Study

Intestinal lymphoma in a 14 year old MN DSH cat

A 14-year-old neutered male DSH cat, previously managed for hyperthyroidism, was presented for chronic soft stool and weight loss with decreased appetite. The physical exam revealed diffusely thickened small intestine, cachexia, and mild dehydration. The CBC showed moderate leukocytosis with a left shift, elevated monocytes, and elevated eosinophils. Blood chemistry demonstrated mildly elevated amylase and mildly elevated lipase with a moderately excessive T4 value and mildly decreased magnesium.

A 14-year-old neutered male DSH cat, previously managed for hyperthyroidism, was presented for chronic soft stool and weight loss with decreased appetite. The physical exam revealed diffusely thickened small intestine, cachexia, and mild dehydration. The CBC showed moderate leukocytosis with a left shift, elevated monocytes, and elevated eosinophils. Blood chemistry demonstrated mildly elevated amylase and mildly elevated lipase with a moderately excessive T4 value and mildly decreased magnesium.

DX

Intermediate intestinal lymphoma

Sonographic Differential Diagnosis

Infiltrative neoplasia is most likely (lymphoma, mast cell). Severe inflammatory bowel disease is also possible.

Image Interpretation

Diffuse areas of the distal small intestinal exhibit mucosal and muscularis thickening. There is echogenic mesentery and hyperechoic mesenteric root lymphadenopathy.

Outcome

The patient was administered a protocol of prednisone/chlorambucil with antibiotics and adjustment of the methimazole therapy on the presumption of small cell lymphoma or aggressive inflammatory bowel disease as the underlying pathology.

Clinical Differential Diagnosis

Intestinal lymphoma/other neoplasia, severe IBD, FIP, pancreatitis, complications to hyperthyroidism, GI foreign body.

Sampling

Ultrasound guided FNA was performed as a cursory sampling procedure given the owner’s reluctance for full thickness surgical biopsies as well as aversion to US-guided tru-cut biopsies. 22g and 20g FNA of the echogenic mesenteric LN and intestinal mucosa was performed utilizing the corkscrew technique (the jab technique did not provide an adequate sample). Cytology of the lymph nodes revealed a highly cellular sample with increased intermediate prolymphocyte percentage suggestive for intermediate lymphoma. Cytology of the small intestine revealed a mixed lymphocytic inflammation; both inflammatory bowel disease and small cell lymphoma are possible.