Case Study

Colonic mast cell tumor in a 10 year old MN DSH cat

10-year-old MN DSH was presented for fresh blood in stools, stranguria and vomiting. A mild monocytosis was present on the CBC. The blood chemistry revealed a hypercholesterolemia. A urinalysis was not performed.

10-year-old MN DSH was presented for fresh blood in stools, stranguria and vomiting. A mild monocytosis was present on the CBC. The blood chemistry revealed a hypercholesterolemia. A urinalysis was not performed.

Sonographic Differential Diagnosis

Annular descending colonic mass-obstructive. Colonic carcinoma, lymphoma, mast cell disease, other neoplasia, minor potential for granulomatous disease.

Image Interpretation

A mural mixed hypoechoic annular mass is noted in the descending colon. The hyperechoic luminal dirty shadow to the left of the mass suggests obstructive pattern. The lesion satisfies neoplastic criteria.

DX

Colonic mast cell tumor

Outcome

A total colectomy was recommended, however, the owners elected to treat medically with oral prednisone. The patient was lost to follow-up.

Clinical Differential Diagnosis

Neoplasia of the urinary tract causing a partial obstruction and in turn stranguria. Other causes of stranguria involving the lower urinary tract pathology: idiopathic cystitis, urolith, polyp, urinary tract infection (which can occur in older cats, particularly secondary to the presence of urolithiasis or nephrolithiasis. Gi pathology: gastrointestinal neoplasia (lymphoma, adenocarcinoma, leiomyoma, leiomyosarcoma, mast cell tumor), foreign body, granuloma or abscess of a surrounding organ (intestine, lymph node) causing compression of the urinary bladder and in turn causing stranguria (due to compression of the urinary bladder), vomiting and blood in the stool.