Case Study

Intestinal lymphoma (Intraoperative ultrasound) in a 17 year old FS DSH cat

This 17-year-old FS DSH cat was presented for anorexia and weight loss. The physical exam revealed palpably thickened small intestine and mild dehydration. The original CBC revealed moderate leukocytosis with a left shift and mild anemia. The patient was treated with broad spectrum antibiotics. Ten days later, the cat exhibited mild persistence of signs. The recheck blood work demonstrated mild leukocytosis with mild elevations in BUN, ALT, and amylase. The T4 value was high normal with a severely elevated free T4.

This 17-year-old FS DSH cat was presented for anorexia and weight loss. The physical exam revealed palpably thickened small intestine and mild dehydration. The original CBC revealed moderate leukocytosis with a left shift and mild anemia. The patient was treated with broad spectrum antibiotics. Ten days later, the cat exhibited mild persistence of signs. The recheck blood work demonstrated mild leukocytosis with mild elevations in BUN, ALT, and amylase. The T4 value was high normal with a severely elevated free T4. The coagulation panel demonstrated twice normal PTT and mildly elevated fibrinogen. Urinalysis showed PH 6.5, USG 1.042, cloudy appearance, protein 1+, and microalbuminuria twice normal.

DX

Low-grade intestinal lymphoma

Sonographic Differential Diagnosis

IBD with focal complicating regional detail loss. Suspect regional LSA, mastocytosis, F.I.P. or complicated inflammatory bowel disease.

Image Interpretation

Diffuse intestinal thickening with relatively uniform hypertrophy of the muscularis. Regional severe muscularis hypertrophy with focal loss of mural detail in the submucosa. Regional area of detail loss appears resectable.

Outcome

The patient was prescribed an oral, bland chemotherapeutic protocol of immune suppressive prednisolone, chlorambucil and broad spectrum antibiotics. The cat responded well to therapy, gaining weight with a strong appetite 5 months post diagnosis.

Comments

After consultation with the pathologist, the hypertrophy of the muscularis was physiological in response to functional obstruction or a “pseudohypertrophy syndrome.” Only islands of cross over infiltrative lymphoma were visualized within the submucosa and muscularis; the diagnosis was consistent with diffuse, low grade mucosal lymphoma typical of older cats. In his opinion, these patients tend to respond better to therapy and have a less aggressive form of lymphoma than the forms that involve the submucosal and muscularis layers in a diffuse manner. Since the regions of detail loss of the intestinal layers were minimal, physiological hypertrophy of the muscularis is most consistent with the sonographic presentation as opposed to infiltrative disease of the muscularis/submucosa. The minor areas of detail loss between the muscularis, submucosa and mucosa may have corresponded to the “islands” of cross-over infiltrate that the pathologist had described (see Image 3). Concurrent mast cell disease of the mesenteric lymph node was considered a complicating factor but would most likely not be treated differently. Regardless, the owner declined aggressive chemotherapy.

Clinical Differential Diagnosis

Hyperthyroidism, IBD, neoplasia, pancreatitis, trichobezoar.

UA PH

6.5

UA PH

6.5

Sampling

Intraoperative ultrasound and surgical resection of the area of detail loss revealed focal lymphoma. Regions of lack of detail loss revealed inflammatory bowel disease. See comments.