Case Study

Prostatic mass with likely metastatic lung disease in a 19 year old MN Chihuahua

A 19-year-old canine, NM Chihuahua was presented for evaluation of pleural effusion and an abdominal mass. Abnormalities on serum biochemistry were azotemia and elevated cholesterol and triglycerides. Thoracic radiographs revealed pleural effusion and normal cardiac silhouette.

Sonographic Differential Diagnosis

Prostatic and sublumbar LN masses likely prostatic carcinoma. Likely thoracic metastasis with secondary pleural effusion or paraneoplastic effusion-pneumonitis.

Image Interpretation

Prostatic mass with mineralization suggestive for carcinoma. Lymph node metastasis is most likely the cause of sublumbar mass. Normal echocardiogram (not shown) with undefined pleural effusion. Hemorrhagic pleural effusion is a significant concern in this patient; it is likely the abdominal mass has metastasized to the lungs causing necrosis of vasculature and secondary hemorrhage. Prognosis is extremely guarded to poor.

DX

Prostatic mass likely carcinoma, sarcoma less likely.

Outcome

The patient passed away.

Comments

A thorough physical exam with caudal abdominal and rectal palapation would have narrowed the region of interest to the caudal abdomen in this patient. However, the presence of pleural effusion in a dog always indicates an abdominal sonogram to assess for a potential primary tumor.

Clinical Differential Diagnosis

Mass – neoplasia, granuloma, abscess, hydronephrosis, splenic torsion. Pleural effusion – transudate, modified transudate (neoplasia, lung lobe torsion, heart disease), septic exudate, non-septic exudate (blood, chyle).