Case Study

RAD – US – Suspected lymphoma supported by FNA/tele cytology in a 8 year old MN Labrador Retriever dog

History: An 8-year-old NM Labrador Mix with a history of being on Rimadyl for 6 months was presented for evaluation of intermittent vomiting, inappetence, and lethargy for a week. On physical examination, ascites was present. Urinalysis was with reference limits. Abnormalities on CBC and serum biochemistry were mild anemia (33%) and elevated ALT activity (310). The ascitic fluid was quantified as a modified transudate

DX

Suspect lymphoma

Sonographic Differential Diagnosis

Lymphoproliferative presentation. This is strongly suggestive for round cell neoplasia or similar neoplastic event involving mesenteric, sublumbar and hepatic lymph nodes. Potential concurrent right adrenal gland pathology, yet obscured by underlying inflammation. If FNA of the lymph nodes are not diagnostic or free fluid is not definitively diagnostic then exploratory surgery with full thickness biopsies would be necessary

Image Interpretation

Rads of the thorax and abdomen – A large elongated retroperitoneal mass effect with marked reduction of the retroperitoneal detail is noted. A regional decrease in peritoneal detail is noted as well. The peritoneal viscera are displaced ventrally. Neither the left nor the right kidney can be clearly delineated. The mass effect is elongated in the craniocaudal direction and cannot be fully delineated within the hypogastrium. The peritoneal stripe highlighting the enlarged retroperitoneal space is well delineated. The mass effect is bilateral, but appears to be more pronounced on the right side. A maldigestion pattern is noted. There is moderate hypovolemia with microcardia and under-perfusion of the lung. A generalized age related reticular pattern is noted as well as multiple pulmonary osteomas/pleural plugs. No mediastinal enlargement is noted.

Ultrasound –

Sonographic Interpretation: The abdomen in this patient revealed similar ascites compared to the prior sonogram. Regional lymph node was enlarged and measured 1.32 cm. Free fluid and distorted lymph node marked as pancreas in the pancreatic region measured 6.7 x 1.87 cm. Regional inflammation was noted throughout the abdomen and encompassed primarily around the mesenteric root. Sublumbar lymphadenopathy was noted. An enlarged lymph node was noted near the aortic trifurcation and measured 3.0 x 2.0 cm. This is likely hepatic lymph node. Nodular omentum was noted throughout the midabdomen.

Outcome

Age related changes of the skeleton and lung.
Consider renal or adrenal neoplasia with retroperitoneal carcinomatosis, neoplastic effusion or hemorrhage as well as hydronephrosis/hydroureter/urinoma with retroperitoneal urine or inflammation, pyonephrosis/pyoureter/renal abscessation with retroperitoneal cellulitis.
Further definition requires a full abdominal ultrasound.
Administer supportive care and rehydrate with IV fluids.

Comments

Follow-up abdominal ultrasound: Left kidney slight pyelectasia and thickened cortices; right kidney swollen with slight pyelectasia and regional free fluid. Enlarged sublumbar lymph nodes. Significant inflammation deriving from lymph node pathology present around right adrenal wich was not visualized. Minor liver portal markings. Regional inflammation and enlarged lymph nodes throughout cranial abdomen. Free fluid with echogenic debris.

Assessment: free fliuid likely derived from lymphatic strangulation and lymphatic obstruction with fluid produced from hydrostatic pressure within the lymphatics.

Recommend FNA/cytology of lymph nodes and liver

Followup ultrasound 3 days later: similar ascites as in the previous scan. Right adrenal obscured by reactive fat. Slightly enlarged spleen with heterogenous changes. Regional lymph node was enlarged and measured 1.32 cm. Free fluid and distorted lymph node marked as pancreas in the pancreatic region measured 6.7 x 1.87 cm. Regional inflammation was noted throughout the abdomen and encompassed primarily around the mesenteric root. Sublumbar lymphadenopathy was noted. An enlarged lymph node was noted near the aortic trifurcation and measured 3.0 x 2.0 cm. This is likely hepatic lymph node. Nodular omentum was noted throughout the midabdomen.

Clinical Differential Diagnosis

Ascites – neoplasia, chronic-active hepatopathy, portal hypertension, pericardial effusion;
Rimadyl induced gastritis/gastric ulceration

Sampling

FNA and tele cytology of
1. abdominal fluid: primarily atypical lymphoid cells suggesting lymphoma, likely leaking from another organ
2. lymph node: supportive of moderate eosinophilic lymphadenitis, likely draining from intestine
Recommend continued evaluation of abdominal masses for high grade lymphoma.