Muffled lung sounds often noted with thymoma

Muffled lung sounds often noted with thymoma

Jan 01, 2004

Signalment: Canine, West Highland White Terrier, 10 years old, male neutered, 20 lbs.

Clinical history: The dog was diagnosed with ascites and pleural effusion by the family veterinarian. There has been some weight loss of about 5 lbs. noted for the last month. The dog is eating and drinking fine.

Table 1: Results of laboratory tests
Physical examination: The findings include a rectal temperature of 101.5° F, heart rate of 120 beats/min, respiratory rate of 80 breaths/min, slightly depressed attitude, severe dental disease, distended abdomen and muffled heart sounds. There was 750 ml of fluid removed from the thorax. Therapy has included enrofloxacin, furosemide and spirolactone. The ECG shows a heart rate of 110 bpm and a normal sinus rhythm.

Laboratory results: A complete blood count, serum chemistry profile and urinalysis were performed and are outlined in Table 1.

Ancillary tests: The thoracic and abdominal fluid analysis shows the fluid to be a transudate. The Snap 3Dx test is negative.

Radiograph examination: The thoracic and abdominal radiographs were done.

Image 1, 2, and 3.
My comments: The thoracic radiographs show evidence of pleural effusion, dilated intrathoracic trachea and possible cranial mediastinal mass. The abdominal radiographs show thickened gastric and intestinal walls.

Ultrasound examination: Thorough thoracic and abdominal ultrasonography was performed.

My comments: The liver shows an increased mixed echogenicity in its parenchyma. The caudate liver lobe is prominent. There are hypoechoic irregular-shaped lesions in the left medial and left lateral liver lobes. No masses noted within the liver parenchyma. The gall bladder is mildly distended, and its walls are not thickened or hyperechoic. The gall bladder is filled with sludge material. The spleen shows an inhomogeneous texture in its parenchyma. No masses noted. The left and right kidneys are similar in size, shape and echotexture. Each kidney shows an inhomogeneous texture in the renal cortex. No masses or calculi were noted in either kidney.

The urinary bladder is distended with urine and contains some urine sediment material. No masses or calculi noted. The left and right adrenal glands are similar in size and shape. The stomach and intestinal walls are slightly thickened. The colon is normal. The pancreas shows an inhomogeneous texture in its parenchyma. There is a mild to moderate amount of pleural effusion noted. The echocardiogram is basically normal except for mild thickening of the mitral valve. There is an irregular-shaped, mass-like structure seen attached to the external wall of the right heart.

Case management: In this case, cranial mediastinal mass and chronic protein-losing enteropathy is the clinical diagnosis. This cranial mediastinal mass is usually a lymphoma or thymoma. Thymoma is most likely in this case and surgical removal of this intrathoracic mass may not be possible. Fine needle aspirations of the cranial mediastinal mass for cytologic examination are warranted to confirm the diagnosis of thymoma. The chronic protein-losing enteropathy is most likely because of chronic inflammatory bowel disease and secondary lymphangiectasia.