This week’s case is an 11 year old male neutered domestic medium haired cat. Thoracic radiographs for routine staging of a left pelvic limb fibrosarcoma. On physical exam, there was a firm mass over the pelvis. Abdominal respiratory effort was noted, as well as an arrhythmia, but no murmur was ausculted. What are your findings?
On lateral projections of the thorax, the cardiac silhouette is markedly enlarged and misshapen, with a prominent caudal bulge. The caudal vena cava is not clearly visualized. There is retraction of the lung lobes and increased soft tissue in the pleural space, indicating pleural effusion. There is also a diffuse, patchy alveolar pattern throughout the lungs. In the portion of the abdomen included, the hepatic silhouette is not visible. The stomach is positioned cranially near the diaphragm. On the v/d projection, tbe pulmnonary vessels are enlarged and the cardiac silhouette occupies the width of the thorax. The central portion of the diaphragm is not clearly visible.
The most likely differential diagnosis is peritoneal pericardial diaphragmatic hernia to explain the lack of hepatic silhouette in the abdomen and the marked enlargement of the cardiac silhouette. The pleural effusion and alveolar pattern are most consistent with heart failure. Since the cardiac silhouette cannot be fully evaluated on the radiographs, echocardiography is recommended. Abdominal ultrasound can be used to confirm the diaphragmatic defect and investigate the organs in the pericardial sac.
Peritoneal pericardial diaphragmatic hernia with pericardial effusion and left heart failure due to unclassified cardiomyopathy.
PPDH is a congenital failure of the diaphragm to close. A diaphragmatic remnant may sometimes be identified ventral to the caudal vena cava (1), however was not visible in this case. This cat was asymptomatic for the PPDH which was discovered on screening thoracic radiographs. The cardiac failure complicated the diagnosis and limited options for therapy.
- Berry, C.R. et all. Dorsal peritoneopericardial mesothelial remnant as an aid to the diagnosis of feline congenital peritoneopericardial diaphragmatic hernia. Veterinary Radiology 1990:(31) 5, p 239-245