Canine, mixed breed, 10-year-old, male castrated, 88 lbs.
The dog presents today for coughing for the last 1.5 weeks and labored breathing and wheezing for the last few days. The dog's
appetite is somewhat decreased. The dog has a clinical history of springtime sneezing, coughing and wheezing for many years
now. Therapy has included the administration of Theo-Dur, cephalexin, Drontal Plus, and dexamethasone, and started the day
before the examination.
The findings include rectal temperature 102.8° F, heart rate 110/min, respiratory rate 32/min, pink mucous membranes, normal
capillary refill time and normal heart sounds. Abnormal findings showed weight gain of about 11 lbs., distended abdomen, bilateral
crackles for lung sounds, audible wheeze on inspiration, normal respiratory rate but some diaphragmatic breathing pattern
noted, mild pyoderma, slightly enlarged popliteal lymph nodes and a slight limp of the right hind leg.
Table 1: results of laboratory tests
A complete blood count, serum chemistry profile and urinalysis were performed and are outlined in Table 1.
Survey thoracic and abdominal radiographs were done. The thoracic radiographs show a generalized increase in interstitial
lung pattern and a mild rounding of the cardiac silhouette that is normal for the dog's conformation of the thorax.
Photos 1 & 2; Radiographic pics
The abdominal radiographs show an enlarged liver, caudal displacement of the stomach, large soft tissue mass located at the
tail of the spleen, mild spondylosis, lumbosacral instability and osteoarthritis of the coxofemoral joints.
Thorough abdominal ultrasonography was performed. The dog was positioned in dorsal recumbency for the ultrasonography. The
ultrasound images provided are from this dog's cranial abdomen.
The liver shows a uniform increase in mixed echogenicity. No obvious cancerous masses noted within the liver parenchyma, but
there are a lot of echogenic changes noted in this dog's liver parenchyma. The gallbladder is mildly distended, and its walls
are not thickened or hyperechoic.
Photos 3 - 5; Ultrasound pics
The gallbladder does contain some sludge material. The spleen shows uniform echogenicity except for the tail region of the
spleen where there is an irregular mixed echogenic mass with distinct borders that could be located within the splenic parenchyma.
The left and right kidneys are similar in size, shape and echotexture. No 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 stomach wall appears
to be normal.
In this case, possible splenic mass and seasonal bronchitis from inhaled allergens is the clinical diagnosis. At this point,
an exploratory laparotomy should be performed for possible spleen removal and histopathologic examination.
At surgery, the surfaces of the liver lobes and regional lymph nodes should be inspected for possible metastatic disease.
No obvious evidence of neoplasia was noted in the thoracic cavity. Management of the seasonal bronchitis should be continued.
Two days later, an exploratory laparotomy was performed. Two lobulated masses (each lobulated mass measured 12 cm x 12 cm)
with omental adhesions and about 1.5-2 inches of involved anti-mesenteric wall of the jejunum were found at surgery. These
lobulated masses were removed by ligating omental vessels and a jejunal resection done. The tail of the spleen was free of
obvious mass lesions. Therefore, what appeared to be a soft tissue mass of the tail of the spleen was actually a soft tissue
mass affecting the jejunum and omentum. The liver and regional lymph nodes were also free of obvious metastatic lesions. The
histopathologic examination confirmed a diagnosis of leiomyosarcoma with a high mitotic rate – an uncommon tumor of the intestinal
tract. Actually, this tumor type is generally a better prognostic tumor if completely removed than is any hemangiosarcoma.
The owner reported the dog's breathing improved two days after surgery. The question to be asked now is "Could the dog's breathing
problem have been caused by chronic abdominal pain?"
Recheck ultrasonography of the abdomen every six months would be indicated for the next few years as well as monitoring the
dog for changes in body weight, appetite and attitude. Chemotherapy is not normally administered after surgery for this tumor
type. Most likely, this is a great diagnosis for this dog.
Fact sheet on leiomyosarcoma in dogs
- Leiomyosarcoma is an uncommon malignant tumor arising from the smooth muscle of the stomach and intestinal tract.
- Tumors tend to be locally invasive by remaining confined to the intestinal tract and slow to metastasize to distance organs.
- Tumors occur mostly in middle-aged to older dogs and no breed or sex predisposition.
- Clinical signs are usually vague and nonspecific: stomach may show abdominal discomfort, weight loss and vomiting; small intestine
may show vomiting, weight loss, borborygmus and flatulence; and cecum and large intestine may show tenesmus that can lead
to rectal prolapse.
- Physical examination findings may be nonspecific, palpable rectal or abdominal mass, and/or infrequently distended, painful
loops of intestines on abdominal palpation.
- Results of the CBC, serum chemistry profile and urinalysis are usually normal. Hypoglycemia has been reported as a part of
the paraneoplastic syndrome.
- Abdominal ultrasonography may show a thickened wall of the stomach or intestine.
- Positive contrast radiography of stomach and intestine may show a space-occupying mass.
- Endoscopy and mucosal biopsy are usually non-diagnostic because most tumors are deeper than the mucosal surface.
- Surgical biopsy is often required to confirm the diagnosis and tumor type.
- Surgical resection is the preferred treatment and curative because most tumors are usually confined to the gastrointestinal
tract and slow to metastasize to distance organs. Carefully evaluate for metastasis in the regional lymph nodes, liver, pancreas
and lungs before performing extensive surgery.
- After complete resection perform regular physical examination and abdominal and thoracic radiography at 1, 3, 6, 9 and 12
months after surgery.
- Incomplete resection may require symptomatic support to relieve clinical signs and chronic pain.