Case Study

Pyogranulomatous inflammation of enlarged mesenteric lymph nodes in a 15 year old MN DSH cat

A 15-year-old MN DSH with history of constipation and inappropriate defecation was presented for lethargy, decreased appetite, and hypersalivation. Physical examination was limited due to the aggressive nature of the patient. The owner was advised to add a second litter box to the house and monitor his behavior. The patient presented a month later for not himself. Physical examination was again limited due to patient’s aggression. Radiographs showed a moderately filled colon, and the heart rotated laterally.

DX

Open. Mesenteric lymph node: hemorrhage and pyogranulomatous inflammation.

Sonographic Differential Diagnosis

Aggressive mesenteric root lymphadenopathy. Rule out mast cell disease, lymphoma, granulomatous disease, FIP, bacterial lymphadenitis.

Image Interpretation

The gastrointestinal tract was largely normal, however two enlarged mesenteric root lymph nodes were noted; one was 1.8 x 1.4cm and another was 0.9cm. There was hyperechoic mesentery in this region. The patient was visibly painful upon imaging of these structures. There were sampled by fine needle aspirate with attempt at drainage. Fine needle aspirate recovery was solid. This is highly suggestive for lymphoma or aggressive lymphadenitis.

Outcome

The patient was recommended for treatment with broad spectrum antibiotics, Vitamin B injections, and potential low-dose Prednisone. The patient was treated with subcutaneous fluids, Convenia, Dexamethasone, and discharged with oral Buprenex. The patient continued to do poorly, owners reported having to force feed cat otherwise he refuses to eat. The patient was treated with Convenia and Diazepam, and discharged with Cyproheptadine. The patient continued receiving force feedings at home, but started intermittently vomiting. The patient was given Mirtazapine and I/D diet. Several weeks later due to poor quality of life and no improvement, the patient was humanely euthanized.

Comments

Given the lack of response, dry form FIP, neoplasia such as lymphoma with secondary inflammation, or resistent bacterial infaction (MRSA or similar), would be consistent with the outcome. Unfortunately post mortem was not a possibility.

Clinical Differential Diagnosis

GI tract – IBD, neoplasia, motility disorder, foreign body, dietary, infectious (bacterial, fungal). Liver – cholangio-hepatitis complex, infectious, toxin, neoplasia. Neurological – cognitive dysfunction, neoplasia.