CT features of gastrointestinal spindle cell, epithelial, and round cell tumors in 41 dogs

There is sparse published information on computed tomographic (CT) characteristics of canine gastrointestinal tumors. The purposes of this multi-center, retrospective, descriptive study were to describe the CT features of histologically-confirmed canine gastrointestinal spindle cell, epithelial, and round cell tumors and, when available, describe the corresponding ultrasound findings. The inclusion criteria were as follows: availability of pre-and post-contrast CT study, and a histopathological diagnosis of the lesions. Recorded parameters were tumor size, location, gastrointestinal wall layers involvement, lesion's growth and enhancement patterns, tumor margination, presence of stenosis, mineralization, ulcerations, lymphadenopathy, or other lesions in the abdomen/thorax. When available, ultrasound images were evaluated. Forty-one dogs met the inclusion criteria and had the following histological diagnoses: 21/41 (51%) spindle cells (7 leiomyomas, 14 leiomyosarcomas/gastrointestinal stromal tumors (GISTs)), 13/41 (32%) epithelial (adenocarcinoma), and 7/41 (17%) round cell (lymphoma) tumors. The growth pattern was concentric, eccentric, and mixed in epithelial, spindle cell, and round cell tumors, respectively. Spindle cell tumors had the largest main volume and involved the outer gastrointestinal layer with an unaffected inner layer. Leiomyosarcomas/GISTs showed irregular margins compared to leiomyomas. Only lymphomas showed multifocal gastrointestinal involvement. Nine carcinomas and six spindle cell tumors caused partial stenosis with secondary sub-obstruction. Mineralizations were more frequent in spindle cell tumors (10/21) and absent in lymphomas. Lymphadenomegaly was widespread in lymphomas, regional in leiomyosarcomas-GISTs and adenocarcinomas, and absent in leiomyomas. The reported CT features may be useful in prioritizing the differential diagnosis between spindle cell, epithelial, and round cell tumors, similar to those reported on ultrasound.

Ultrasonographic features of a urinary bladder leiomyoma in a cat

Case summary

Leiomyoma of the urinary bladder in cats is infrequently documented in the literature, and a description of the ultrasonographic appearance has never been reported. A 9-year-old female spayed cat presented with a 6-month history of intermittent hematuria and progressive pollakiuria. On abdominal ultrasound, a large ovoid mass of mixed echogenicity was seen originating from the ventral apical bladder wall. The mass had faint peripheral hyperechoic radiating striations and was mildly vascularized, especially at its 1.5 cm point of origin from the wall. A partial cystectomy was performed to remove the mass that filled the bladder lumen. Microscopically, the well-demarcated mass extended from the inner muscular layer of the wall into the submucosal layer and was diagnosed as a leiomyoma. Surgical excision was curative.

Relevance and novel information

This is the first ultrasonographic description of a bladder leiomyoma in a feline patient. Smooth muscle tumors should be included on the differential diagnosis list in future cases with similar ultrasonographic features and chronic lower urinary clinical signs.

Case Report: Giant Multiloculated Pseudocystic Jejunal Leiomyosarcoma in a Dog: Atypical Morphologic Features of Canine Intestinal Leiomyosarcoma

A 10-year-old intact female Rottweiler dog weighing 29 kg presented with 2 days history of vomiting, anorexia, and lethargy to KonKuk University Teaching Hospital, Seoul, South Korea. Ultrasonography and computed tomography (CT) scannings revealed a well-demarcated, large mass (29 × 19 × 11 cm) with numerous fluid-filled cavities. Metastases to adjacent lymph nodes were also identified on CT. This large mass and the affected intestinal segments were excised for palliative purposes. Postoperatively, the dog recovered uneventfully without any complications. The cut surface of the mass showed an exophytic growth pattern of multiloculated cystic lesions filled with serosanguineous fluid, large cavities filled with necrotic exudate, and fistulous connections between the intestinal lumen and the necrotic cavity in the mass. On histopathology, the mass was a spindle cell neoplasm expanding from the jejunal muscular layer and with pseudocystic changes. Additional immunohistochemical analysis using antibodies against smooth muscle actin, desmin, and CD-117 demonstrated that the mass was consistent with a leiomyosarcoma. Six months post-operatively, plain radiography revealed an abdominal mass, suspected to be recurrence from jejunal leiomyosarcoma. The owner decided to euthanize the dog due to financial constraints. This case report describes the atypical morphology and clinical progression of a large canine jejunal leiomyosarcoma, which had similar clinical features as those of human leiomyoma and leiomyosarcoma.

Diagnosis and treatment of a caecal mucocoele in a dog

An 11-year-old male intact Staffordshire Bull terrier was referred for diabetic ketoacidosis. Abdominal ultrasonographic examination revealed a 5 cm × 2 cm intraluminal caecal mass-like structure. Exploratory laparotomy and typhlectomy were subsequently performed. Histopathology of the caecal mass-like structure was consistent with a caecal mucocoele, defined as a cystic dilation of the caecal lumen with stasis of mucus. This lesion has been previously described in humans, where it is termed an appendiceal mucocoele. The patient was euthanased 58 days post-operatively due to unrelated diabetic complications.

Dual-phase computed tomography angiography of intestinal carcinoid tumor as a lead point for cecocolic intussusception in a dog

In an 8-year-old Labrador Retriever with progressive anorexia, constipation, and depression, CT revealed intussusception of the cecum into the ascending colon and a small cecal mass showing strong enhancement on arterial phase. The ileocecocolic junction was surgically resected and histologically diagnosed as cecocolic intussusception with carcinoid tumor. The carcinoid tumor worked as a lead point of intussusception in this case. Dual phasic CT is useful to assess the presence of gastrointestinal tumors as lead points in old dogs with intussusception.

How useful is abdominal ultrasonography in dogs with diarrhoea?

OBJECTIVE

To assess the utility of abdominal ultrasonography in the diagnostic work-up of dogs with diarrhoea.

METHODS

Retrospective cross-sectional study based on a referral population of dogs with diarrhoea. Associations between the clinical signs, use of abdominal ultrasonography, results of abdominal ultrasonography and subsequent work-up were examined. The utility of abdominal ultrasonography was scored as high, moderate, none or counterproductive based on review of medical records.

RESULTS

Medical records of 269 dogs were reviewed, of which 149 (55%) had abdominal ultrasonography. The most frequent result was no ultrasonographic abnormalities affecting the intestine in 65 (44%) dogs. Ultrasonography results were associated with subsequent work-up as follows: (1) no detected abnormalities and dietary trial; (2) focal thickening of the intestinal wall, loss of intestinal wall layers or enlarged abdominal lymph nodes and ultrasound-guided fine-needle aspirates; (3) diffuse thickening of the intestinal wall or hyperechoic striations in the small intestinal mucosa and endoscopy; and (4) small intestinal foreign body and coeliotomy. Abdominal ultrasonography was considered to be diagnostic without further testing in only four (3%) dogs: two had a portosystemic shunt identified ultrasonographically, one had a linear foreign body and one had a perforated pyloric ulcer. Abdominal ultrasonography had moderate utility in 56 (38%) dogs and no utility in 79 (53%) dogs. Abdominal ultrasonography was considered counterproductive in 10 (7%) dogs because results were either falsely negative or falsely positive.

CLINICAL SIGNIFICANCE

These results should prompt clinicians to reconsider routine use of abdominal ultrasonography in dogs with diarrhoea.

Partial gastrectomy for resection of a gastric leiomyoma in a guinea pig (Cavia porcellus)

CASE DESCRIPTION A 4-year-old sexually intact male pet guinea pig (Cavia porcellus) was evaluated for a routine wellness examination. CLINICAL FINDINGS During physical examination, a small mass was palpated in the cranial aspect of the abdomen. Abdominal radiographic and ultrasonographic findings were suggestive of a gastric mass. Cytologic evaluation of a fine-needle aspirate of the mass was indicative of spindle cell proliferation most consistent with a sarcoma. TREATMENT AND OUTCOME The patient was anesthetized, and an exploratory laparotomy and partial gastrectomy were performed to resect the gastric mass. Histologic and immunohistochemical examinations of the mass revealed that it was a gastric leiomyoma. The patient recovered from surgery without complications. No evidence of mass recurrence was observed during an abdominal ultrasonographic examination performed approximately 19 months after surgery. CLINICAL RELEVANCE To our knowledge, this was the first report of the clinical diagnosis and successful surgical treatment of a gastric neoplasm in a guinea pig. Gastric leiomyomas are not uncommon in guinea pigs, and although benign, they can cause clinical signs if they become large enough to impair gastric function. Gastrointestinal surgery should be considered as a treatment option for guinea pigs with similar gastric neoplasms.

ULTRASONOGRAPHIC FEATURES OF CANINE GASTROINTESTINAL STROMAL TUMORS COMPARED TO OTHER GASTROINTESTINAL SPINDLE CELL TUMORS

Canine gastrointestinal stromal tumors (GISTs) are a recent subtype of gastrointestinal spindle cell tumor recognized with the increasing use of immunohistochemistry. To our knowledge, no imaging features have been described in immunostochemically confirmed canine GISTs. The objective of this retrospective, cross-sectional study was to describe ultrasonographic features of canine GISTs compared with other spindle cell tumors. Thirty-seven dogs with an ultrasonographically visible gastrointestinal mass and a histopathologic diagnosis of spindle cell neoplasia were examined. Immunohistochemistry staining was performed for retrieved tissue samples to further differentiate the tumor type and each sample was interpreted by a single veterinary pathologist. Ultrasonographic features recorded examined included mass echogenicity, homogeneity, presence of cavitation, layer of origin, bowel wall symmetry, and loss of wall layering, location, size, vascularity, and evidence of perforation or ulceration. Tumor types included 19 GISTs, eight leiomyosarcomas, six leiomyomas, and four nonspecified sarcomas. Gastrointestinal stromal tumors were significantly more likely to be associated (P < 0.03) with abdominal effusion than other tumor types. There was overlap between the anatomical locations of all tumors types with the exception of the cecum where all eight tumors identified were GISTs. Besides location, there were no unique ultrasound features of GISTs that would allow distinction from other gastrointestinal spindle cell tumors. Similar to previous studies, GISTs appeared to be the most common spindle cell tumor associated with the cecum in our sample of dogs. The high frequency of abdominal effusion with GIST's was of unknown etiology could possibly have been due to septic peritonitis.

Imaging diagnosis--ultrasonographic appearance of small bowel metastasis from canine mammary carcinoma

A 10-year-old entire female Beagle dog was evaluated for an acute history of lethargy, anorexia, and diarrhea. Mammary tumors were detected during physical examination. Ultrasonographic scanning revealed the presence of a unique pattern of multiple, well-defined and well-marginated hypoechoic nodules in the muscularis layer of the jejunum. These nodules were not associated with changes in the rest of the normal intestinal layering and were not causing signs of intestinal obstruction. Mammary carcinoma metastases to the intestinal muscularis layer were diagnosed based on histopathological examination.

Diagnostic utility of abdominal ultrasonography in dogs with chronic diarrhea

BACKGROUND

Chronic diarrhea is common in dogs and has many causes. Ultrasonographic descriptions of many gastrointestinal diseases have been published, but the diagnostic utility of ultrasonography in dogs with chronic diarrhea has not been investigated.

HYPOTHESIS

Diagnostic utility of abdominal ultrasound will be highest in dogs with GI neoplasia and lowest in those with inflammatory disorders.

ANIMALS

87 pet dogs with chronic diarrhea.

METHODS

Prospective study in which medical records were reviewed and contribution of abdominal ultrasound toward making diagnosis was scored.

RESULTS

In 57/87 (66%) of dogs, the same diagnosis would have been reached without ultrasonography. In 13/87 (15%) of dogs, the ultrasound examination was vital or beneficial to making the diagnosis. Univariable analysis identified that increased diagnostic utility was associated with weight loss (P = .0086), palpation of an abdominal or rectal mass (P = .0031), diseases that commonly have mass lesions visible on ultrasound examination (P < .0001), and a final diagnosis of GI neoplasia. Multivariable regression indicated that utility of abdominal ultrasonography would be 30 times more likely to be high in dogs in which an abdominal or rectal mass was palpated (odds ratio 30.5, 95% CI 5.5-169.6) (P < .0001) versus dogs without a palpable mass. In 15/87 (17%) of dogs, additional benefits of ultrasonography to case management, independent of the contribution to the diagnosis of diarrhea, were identified.

CONCLUSIONS AND CLINICAL IMPORTANCE

Overall, the diagnostic utility of abdominal ultrasonography was low in dogs with chronic diarrhea. Identification of factors associated with high diagnostic utility is an indication to perform abdominal ultrasonography in dogs with chronic diarrhea.

Predicting metastatic potential of gastrointestinal stromal tumors in dog by ultrasonography

Gastrointestinal stromal tumor (GIST), a mesenchymal neoplasm affecting the gastrointestinal tract, shows a variety of clinical behaviors from inactive benign to aggressive malignant in dogs. In this study, the feasibility of using clinically significant ultrasonographic features to predict the metastatic potential of canine GIST was investigated through comparison with actual metastatic incidence and findings of malignancy obtained by postoperative pathological examination. Ultrasonographic features, including large tumor size, irregular margin and heterogeneous internal echogenicity with large hypoechoic areas, related closely with the presence of metastasis as well as a high-risk ranking by the human classification system according to pathological findings. Based on these ultrasonographic features, the potential of metastasis in canine GIST could be preoperatively predicted.

Ultrasonographic appearance of canine gastric polyps

Benign gastric polyps are uncommon in dogs and most are discovered incidentally. Polyps protruding into the pyloric antrum can cause gastric outflow obstruction. Clinical and ultrasonographic findings in seven dogs with histologically confirmed benign mucosal gastric polyps were reviewed. Sonographic findings such as shape, size, echogenicity, location, evidence of gastric wall thickening, wall layering, and size of regional lymph nodes were recorded. Five sessile and two pedunculated masses of different sizes (range 7-60 mm) and echogenicities were found. They primarily arose from the mucosal layer and protruded into the gastric lumen. Only one dog had a large inhomogeneous mass with a poorly visualized gastric wall layering. The polyps were all single, and were located in the pyloric antrum in six out of seven dogs. Although the ultrasonographic appearance allowed a presumptive diagnosis of mucosal gastric polyp, the final diagnosis was determined from histopathologic examination.

Eosinophilic fibrosing gastritis and toxoplasmosis in a cat

A 3-year-old, neutered male Tiffany cat was presented to the Animal Health Trust for investigation of pyrexia and a gastric lesion. Radiography and ultrasound showed severe thickening of the gastric wall and regional lymphadenopathy. There was altered gastric wall layering, predominately due to muscularis thickening. Histopathology confirmed eosinophilic fibrosing gastritis. The cat also had evidence of generalised Toxoplasma gondii infection, which may have been responsible for the gastric changes.

Diagnostic value of ultrasonography in differentiating enteritis from intestinal neoplasia in dogs

One hundred and fifty dogs with histopathologically confirmed intestinal disease were evaluated retrospectively. Sixty-one dogs had enteritis and 89 dogs had intestinal neoplasia. Ultrasonographic findings including the thickness and distribution of the intestinal lesion, the integrity of intestinal wall layering, regional lymph node thickness, the location of the intestinal segment involved, and regional motility were evaluated. Dogs with intestinal tumor had wall thickness (1.5 cm) significantly greater than dogs with NSE lesions (0.6 cm; p < 0.001). Ninety-nine percent of dogs with intestinal tumor had loss of wall layering while 88% of dogs with NSE had normal or altered wall layering (p < 0.001). Dogs with NSE were significantly more likely to have diffuse lesion (72%) than dogs with intestinal tumor (2%; p < 0.001). Lymph node median thickness in 24/61 dogs with NSE was 1.00 cm. The median thickness of the lymph nodes in 56/89 dogs with intestinal tumors was 1.9 cm. A multivariate analysis showed that loss of wall layering alone was an excellent predictive factor in differentiating intestinal tumor from NSE. In our population, dogs with loss of intestinal wall layering were 50.9 times more likely to have a tumor than enteritis.

Comparison of ultrasonographic characteristics of the gastroduodenal junction during pyloroplasty performed laparoscopically or via conventional abdominal surgery in dogs

OBJECTIVE

To evaluate the use of ultrasonography to detect morphologic changes in the pylorus during pyloroplasty performed laparoscopically or via conventional abdominal surgery in dogs.

ANIMALS

10 healthy mixed-breed dogs.

PROCEDURE

Laparoscopic ultrasonography of the pylorus was performed in 5 dogs during laparoscopic pyloroplasty (LP), and ultrasonography of the pylorus was performed in 5 dogs during pyloroplasty via conventional abdominal surgery (CAP group). Appearance and dimensions of the pyloric sphincter were evaluated by use of a 7.5-MHz flexible laparoscopic linear-transducer probe.

RESULTS

Mean +/- SD duration of the ultrasonographic procedure was 11 +/- 3.04 minutes (range, 6 to 18 minutes). In the CAP group, cross-sectional views of the pylorus revealed significant differences between the overall transverse external diameter, overall craniocaudal external diameter, and transverse diameter of the pyloric lumen. After surgery, the pyloric area was significantly increased. Longitudinal views of the pylorus revealed that width of the pyloric ring was significantly less after surgery. Transverse views of the pylorus for the LP group revealed a significant increase in the transverse diameter and craniocaudal diameter of the pyloric lumen after LP. The pyloric area was also significantly increased after surgery. Longitudinal views of the pylorus revealed that width of the pyloric ring was significantly less after surgery. Transverse diameter of the pyloric lumen was significantly increased after LP.

CONCLUSIONS AND CLINICAL RELEVANCE

Analysis of results of this study suggests that ultrasonography is useful for detecting relevant morphologic changes in the pyloric sphincter after pyloroplasty.

Ultrasonographic appearance and etiology of corrugated small intestine

An ultrasound pattern of corrugated, and sometimes thickened, bowel wall has been associated with pancreatitis and small intestinal lymphangiectasia. In a retrospective study, records of dogs and cats with an ultrasound diagnosis of corrugated bowel were examined for age, breed, gender, presenting complaint, abdominal radiographic results, and final diagnosis. Eighteen dogs and six cats had an ultrasound diagnosis of corrugated bowel. The final diagnosis was pancreatitis (12 of 24), peritonitis (4 of 24), enteritis (2 of 24), pancreatic neoplasia (2 of 24), diffuse abdominal neoplasia (1 of 24), lymphocytic-plasmacytic enteritis (1 of 24), thrombosis/infarction (1 of 24), and protein-losing enteropathy and acute renal failure (1 of 24). The presence of bowel wall corrugation, although a nonspecific finding, should alert one-to the possibility of pancreatitis, enteritis, peritonitis, neoplasia, or bowel wall ischemia.

Ultrasonographic and clinicopathologic findings in 21 dogs with intestinal adenocarcinoma

In a retrospective study of 21 dogs with intestinal adenocarcinoma, the signalment, clinical presentation, laboratory findings, ultrasonographic features, treatment, and outcome were reviewed. Anorexia (n = 16), vomiting (n = 15), diarrhea (n = 10), and weight loss (n = 9) were the most common clinical signs reported. Ultrasonographic features that were evaluated included location, length, wall thickness, echogenicity, regional motility, layering, regional lymphadenopathy, and fluid accumulation proximal to the lesion site. All lesions were transmural and associated with complete loss of wall layering. Maximum wall thickening at the lesion site ranged from 7 to 17 mm (median 12 mm, mean 11.9 mm). Most of the dogs had a lesion measuring from 23 to 63 mm in length, (median 40 mm, mean 42 mm). Most intestinal lesions were poorly echogenic and had an irregular lumen. Fluid accumulation proximal to the lesion site was identified in 17 of 21 dogs, and in 13 of 17 dogs the fluid accumulation was considered moderate to severe. Regional lymphadenopathy and/or nodular mesentery/omentum were noted in 12 of 21 dogs. The tumor was located in small intestine for 15 dogs and in the colon for the remaining 6 dogs. Fifteen dogs were treated by surgical resection of the intestinal mass. Their median survival time was 233 days. Only gender appeared to influence survival. Female dogs lived a median of 28 days, whereas male dogs lived a median of 272 days.

Multicentric lymphoma with intestinal involvement in a dog

A 5-year-old, male German shepherd dog was evaluated for a 5-week history of vomiting, diarrhea, lethargy, and weight loss. In abdominal radiographs, there was an unusual corrugated appearance within a loop of intestine. Sonographically, this loop also had a similar corrugated appearance with alternating hyperechoic and hypoechoic bands. Lymph nodes within the abdomen and thorax were enlarged, and a thoracic mass was also detected. Ultrasound-guided fine-needle aspirates of the mesenteric lymph nodes were highly suggestive of lymphoma. After postmortem examination, a diagnosis of multicentric lymphoma with involvement of the gastrointestinal tract was made.

Gastrointestinal ultrasonography of the dog: a review of 265 cases (1996-1998)

The findings of ultrasonography of the gastrointestinal (GI) tract of 265 dogs with GI disorders were analysed retrospectively. The sonographic changes associated with various inflammatory and neoplastic conditions and mechanical obstruction of the GI system were recorded and discussed. Sonographic alterations of the pancreas and the tissues adjacent to the GI tract were also included in the study. Ultrasonographic alterations of the GI tract were classified into three main categories: thickening of the GI wall, changes in peristalsis and dilation of the lumen. Localised thickening of the GI wall with disruption of its structure was caused by both neoplastic diseases and by inflammatory disorders. However, diffuse thickening with retained wall structure was generally associated with inflammatory diseases. The criteria previously established for the ultrasonographic diagnosis of intestinal obstruction were successfully applied to a large number of GI disorders. Pancreatitis was most often associted with hyperchoic mesentery and hypoechoic pancreas mass, but similar alterations were encountered in some cases of gastric or duodenal ulceration. Except in cases of invaginations and intestinal obstructions, the observed ultrasonographic changes were not specific enough for a definitive diagnosis. Nevertheless, ultrasonography proved to be a valuable technique in the diagnostic process of GI disorders of the dog.

A retrospective study into the effects of operator experience on the accuracy of ultrasound in the diagnosis of gastric neoplasia in dogs

The accuracy of three diagnostic techniques in two separate time periods was examined. In the first time period, 18 dogs were referred to the University of Bristol with signs suggestive of gastric neoplasia. Of these 18 dogs, 7 had a positive diagnosis of gastric neoplasia from histopathology samples (38% prevalence). The sensitivity of ultrasound was found to be 42.9% with a specificity of 63.6%. A year later the study was repeated with 40 cases referred for investigation. Of these 40 dogs, 16 had a positive histopathologic diagnosis of gastric neoplasia (40% prevalence). At this time the sensitivity of ultrasound had increased to 81.3 % and the specificity had increased to 70.8 %. The increase in sensitivity was attributed to an increase in operator experience in the performance of the ultrasound examination. This improvement in sensitivity and experience resulted in a greater accuracy at detecting the presence of gastric neoplasia.

Ultrasonographic features of canine gastrointestinal pythiosis

Pythiosis is a chronic pyogranulomatous infection of the gastrointestinal tract or skin caused by the water borne pathogen Pythium insidiosum. The ultrasonographic features of nine dogs with gastrointestinal pythiosis are reported. The stomach, duodenum, jejunum or colon were affected. All dogs had thickening of the gastrointestinal wall and areas with obliteration of the normal layered appearance. In one dog an eccentric mass was found arising from the serosal surface of the wall of the colon with mild diffuse wall thickening. Regional lymph node enlargement was seen in seven of the nine dogs. One dog had invasion of the pancreas and signs compatible with extrahepatic biliary obstruction. When compared to previous reports of gastrointestinal neoplasia, the features of wall thickening, loss of layering and regional lymphadenopathy are not considered specific for gastrointestinal pythiosis. Histological examination of tissue specimens is required for diagnosis.

Ultrasonographic appearance of primary gastric neoplasia in 21 dogs

The ultrasonographic findings in 21 dogs with histologically confirmed primary gastric neoplasia were reviewed. Location, shape of the gastric lesion, evidence of gastric wall thickening, wall layers affected, presence of ulceration, evidence of extension through the gastric wall and lymphadenopathy were recorded. Twelve dogs with carcinoma shared many ultrasonographic features with six dogs that had lymphoma, the majority having sessile masses that appeared to involve all layers of the gastric wall; many also had evidence of ulceration and lymphadenopathy. Signs of extension of the lesion through the serosal surface of the stomach were identified ultrasonographically only in dogs with carcinoma. In contrast, three dogs with leiomyoma or leiomyosarcoma each had a focal mass affecting the gastric antrum, and lymphadenopathy was not identified ultrasonographically in these dogs. Even without any specific patient preparation, ultrasonography enables a morphological assessment of gastric neoplasms that may prompt a tentative diagnosis of gastric neoplasia and stimulate further investigation.

Sonography of the normal feline gastrointestinal tract

The normal sonographic appearance of the stomach in various degrees of distension, the duodenum, the small intestine, and the large intestine was determined in awake and sedated cats. The mean stomach rugal fold thickness was 4.38 mm, and the interrugal thickness was 2.03 mm. No significant difference in stomach wall thickness was seen when the stomach was empty, half full, or full. The duodenal wall thickness was significantly greater than other parts of the small intestine, and this difference was accentuated by sedation (awake mean 2.4 mm; sedated mean 2.71 mm). The mean small intestinal wall thickness was 2.1 mm, and the mean colonic wall thickness was 1.67 mm. The five characteristic sonographic layers similar to that seen in the gastrointestinal tract of other species were routinely identified at all regions of the feline gastrointestinal tract.

Ultrasonography of canine gastric epithelial neoplasia

Signalment, clinical and ultrasonographic findings from 16 dogs with histologically confirmed gastric epithelial neoplasia were reviewed. The most common clinical findings were vomiting, anorexia and weight loss. Hematemesis and melena were uncommon findings. Ten (10/16) dogs were female and there were four Chows. The most common ultrasonographic findings were transmural thickening of the gastric wall associated with altered wall layering. A poorly echogenic lining often was noted on the innermost and/or the outermost portions of the gastric wall, separated by a more echogenic central zone. The distribution of these changes was variable. This ultrasonographic feature, called pseudolayering, was present in 14 dogs. It was believed to most likely correlate to the unevenly layered tumor distribution noted histopathologically. The maximum wall thickening ranged from 1 cm to 2.7 cm. Regional lymphadenopathy was identified ultrasonographically in 15 dogs. Ultrasound-guided fine-needle aspiration biopsy or automated microcore biopsy, endoscopic biopsy, surgical biopsy or necropsy resulted in the diagnosis of carcinoma in 15 dogs and of carcinoid tumor in one dog. The results of this study suggested that ultrasonography was a useful tool for the detection and diagnosis of canine gastric epithelial neoplasia. Furthermore, ultrasonography can assist in obtaining diagnostic samples and in clinical staging of the tumor.

Ultrasonography of abdominal cavitary parenchymal lesions

Cavitary parenchymal lesions are composed of varying amounts of soft tissue, fluid, and/or gas. These cavitary lesions are focal or multifocal and therefore readily detected ultrasonographically. The ultrasonographic appearance of cystic and noncystic cavitary lesions are described. Differential diagnoses for these cavitary lesions in abdominal organs are listed.

Characterization of gastrointestinal tumors

Transabdominal ultrasonography is used increasingly for the evaluation of gastrointestinal disorders in small animals, including neoplasms such as lymphosarcoma, carcinoma, and smooth muscle tumors (leiomyoma, leiomyosarcoma). An updated summary of the clinical studies currently investigating the use of ultrasonography to detect and to characterize gastrointestinal neoplasia is presented in this article.

Ultrasonographic features of intestinal adenocarcinoma in five cats

Adenocarcinoma, followed by lymphosarcoma, are the most common feline intestinal neoplasms. Clinicopathological, survey radiographic, and ultrasonographic findings of five cats with intestinal adenocarcinoma are reported. An abdominal mass was palpable in all five cats, but the mass could be localized to bowel in only two cats. Radiographically an abdominal mass was detected in only one cat. Ultrasonographically there was a segmental intestinal mural mass in all five cats. The mass was characterized by circumferential bowel wall thickening with transmural loss of normal sonographic wall layers. In one cat, the circumferential symmetric hypoechoic bowel wall thickening was similar to that reported for segmental lymphoma. In the other four cats, the sonographic features of the thickened bowel wall were varied, being mixed echogenicity and asymmetric in 3 cats and mixed echogenicity and symmetric in one. The results of the present report suggest that sonographic observation of mixed echogenicity segmental intestinal wall thickening in the cat represents adenocarcinoma rather than lymphosarcoma, although other infiltrative diseases should be considered.