Follow-up studies by large intestinal biopsies and necropsy in dogs with clinical signs of large bowel disease.

The results of follow-up studies in 77 dogs with clinical signs of large bowel disease are presented. In 32 dogs colonic and/or rectal biopsy follow-up studies were done, combined with necropsy in seven dogs. In 45 dogs a follow-up necropsy only was done. The time between the first and the last series of biopsies varied from three to 729 days and between the first series of biopsies and necropsy from one to 980 days. Colitis found in 45 dogs in the initial biopsies was still present in 29 cases in the follow-up biopsy studies and/or at necropsy. Eleven cases showed hystiocytic ulcerative colitis. In general, adenoma, carcinoma and lymphosarcoma were confirmed in the follow-up examination, except for one adenoma, which appeared to be a carcinoma at necropsy. In cases in which the differential diagnosis was adenoma or carcinoma, the necropsy diagnosis was always carcinoma and in cases of a differential diagnosis of lymphosarcoma and/or colitis, lymphosarcoma was always diagnosed at necropsy. Several dogs without colonic changes in the initial biopsies had other gastric or small intestinal lesions at necropsy such as gastritis and enteritis of the small intestine, or tumors, in these areas.     

LYMPHOMA AFFECTING THE URINARY BLADDER IN THREE DOGS AND A CAT

Three dogs and one cat with lymphoma affecting the urinary bladder are reported and the findings on abdominal radiographs and ultrasound are described. Mural lesions representing lymphoma affecting the urinary bladder were identified ultrasonographically in all animals. The most common complications associated with urinary bladder lymphoma were hydronephrosis and hydroureter. In two patients contrast radiography was necessary to detect leakage of urine in the peritoneal and retroperitoneal space. The radiographic and ultrasonographic signs were similar to those reported with other urinary bladder neoplasms; hence urinary bladder lymphoma could not be distinguished from the more common urinary bladder neoplasms, such as transitional cell carcinoma. It is important to include lymphoma in the differential diagnosis of urinary bladder wall thickening and mural mass in dogs and cats.     

Effects of serial ultrasound-guided renal biopsies on kidneys of healthy adolescent dogs

Ten healthy mixed-breed dogs were used to evaluate the functional and structural effects of serial ultrasound-guided renal biopsies obtained with an automated biopsy needle. In each dog, one lateral renal cortex was biopsied at 2, 4, and 6 months of age; the other kidney was the control. Five dogs had two tissue cores and five dogs had four tissue cores taken on each biopsy occasion, and one core was examined microscopically. One week before each biopsy and a month after the final biopsy, the glomerular filtration rate (GFR) was determined by renal scintigraphy. Dogs were then euthanized for evaluation of gross and microscopic lesions attributable to the biopsies. There was no difference between GFR values for biopsied kidneys and those of control kidneys ( P >0.05). Microscopic lesions were not identified in biopsies taken at 2 and 4 months, but focal lesions were found in three of 10 specimens taken at 6 months of age. At necropsy, six of 10 biopsied kidneys had small visible capsular scars, and linear tracts <2 mm wide were observed on cut surfaces in six of 10 biopsied kidneys cut transversely into slices 5 mm thick. Discrete light microscopic lesions were observed in 25 of 452 (5.5%) of randomly selected 6-mm-diameter sections of renal cortex from biopsied kidneys. We conclude that serial renal cortical biopsies can be obtained by our method from healthy adolescent dogs with minimal risk of inducing changes that might be confused with those of a progressive renal disease.     

The histological appearance of peroral gastric biopsies in clinically healthy and vomiting dogs.

A survey of the histology of gastric biopsies in 501 dogs, consisting of 19 clinically healthy dogs and 482 vomiting dogs is presented. Whole stomachs of four young clinically healthy laboratory dogs were used as controls. Eleven percent of forceps biopsies were unsuitable for examination; all suction biopsies were of good quality. Slight to severe gastritis was found in 168 vomiting dogs (35%), whereas five dogs (26%) of the clinically healthy group showed a mainly slight gastritis. Superficial and diffuse gastritis were the most prominent findings in the 168 dogs with gastritis. A single type of gastritis was found in 114 dogs, a combination of different types in 54 dogs. Gastric atrophy was seen in 23 (5%) vomiting dogs and in three (15%) clinically healthy dogs, atrophy with a slight to severe fibrosis in 21 (4%) vomiting dogs, and in 84 (17%) vomiting dogs and two (11%) healthy dogs, gastric fibrosis was present. Carcinomas were seen in 26 vomiting dogs, of which 17 also had gastritis. A differential diagnosis of granulomatous gastritis/carcinoma had to be made in one case. Seven dogs showed a lymphosarcoma, and in six other dogs a differential diagnosis of lymphosarcoma and/or gastritis was made. One adenomatous polyp was seen. In one clinically healthy dog an adenomyoma was diagnosed. Ulceration was found in 24 dogs, but only five of these lacked other lesions. Other biopsy findings were pseudopyloric metaplasia, hyperplasia, cysts, calcification and edema. Some dogs showed "antralization".     

ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION BIOPSY OF BONE LESIONS: A PRELIMINARY REPORT

The purpose of this preliminary study was to determine the feasibility of ultrasound-guided fine-needle aspiration biopsy of suspected neoplastic lesions of bone. Ultrasound-guided fine-needle aspiration biopsy samples were obtained in 23 patients (22 dogs and one cat) with radiographic evidence of a destructive or destructive/productive bone lesion. The lesions were located in the appendicular skeleton in 20 patients and in the axial skeleton in three. Histopathology from tissue core biopsies and/or necropsy was not deemed necessary in 11 patients where ultrasound-guided fine-needle aspiration biopsy results were conclusive for neoplasia. A cytologic diagnosis from ultrasound-guided fine-needle aspiration biopsy was confirmed by histologic samples obtained at surgery or necropsy in five patients. In one of these five, ultrasound-guided fine-needle aspiration biopsy samples were diagnostic for sarcoma when tissue-core biopsy was inconclusive. Both ultrasound-guided fine-needle aspiration biopsy and tissue core biopsy techniques were inconclusive in one patient. Ultrasound-guided fine-needle aspiration biopsy samples were nondiagnostic in five patients where a follow-up histopathologic diagnosis of neoplasia was made. It was concluded that ultrasound-guided fine-needle aspiration biopsy of bone, if diagnostic, may help avoid the need for a tissue-core biopsy in some instances. However, a negative ultrasound-guided fine-needle aspiration biopsy sample does not rule out neoplasia. A negative ultrasound-guided fine-needle aspiration biopsy should be followed by a tissue-core biopsy and histologic analysis in all patients. Ultrasound-guided fine-needle aspiration biopsy seems to be a promising technique for the diagnosis of bone lesions.     

CT-GUIDED BRAIN BIOPSY USING A MODIFIED PELORUS MARK III STEREOTACTIC SYSTEM: EXPERIENCE WITH 50 DOGS

This report describes the results of CT-guided stereotactic brain biopsies performed on 50 consecutive dogs using a modified Pelorus Mark III Stereotactic System. Based on available histopathologic samples (stereotactic biopsy [n = 50], surgery [n = 17], necropsy [n = 9]) the patient population consisted of 34 dogs with primary brain tumors, 2 with invasive nasal adenocarcinomas, and 13 with non-neoplastic brain lesions. Brain tissue was not obtained from one dog. In 22 dogs a final diagnosis was made from tissue subsequently obtained from surgical resection or at necropsy. The final diagnosis was in agreement with the stereotactic biopsy diagnosis in 20 of these 22 dogs. In 17 other dogs without follow-up, stereotactic biopsy provided a diagnosis of a specific primary brain tumor subtype. Postoperative complications associated with the biopsy procedure were assessed in 41 dogs. The other 9 dogs either went directly to surgery (n = 7) or were killed (n = 2) immediately after the biopsy procedure. Thirty-six dogs recovered without apparent clinical complications. Postoperative clinical complications in the remaining 5 dogs included transient epistaxis (1 dog), transient exacerbation of cerebellar signs (1 dog), obtundation progressing to coma (1 dog), and medically uncontrollable seizures (2 dogs). The latter 3 dogs with severe neurologic complications all had large primary brain tumors and had been receiving high doses of phenobarbital and glucocorticoids to control seizures at the time of biopsy. These results suggest that this CT-guided biopsy procedure can provide an accurate pathologic diagnosis of brain lesions detected by CT and MR neuroimaging. Further refinement of both technique and case selection is expected to reduce the rate of clinical complications and to improve the accuracy of the procedure.     

INTRAOPERATIVE SPINAL ULTRASONOGRAPHY IN TWO DOGS WITH SPINAL DISEASE

Ultrasonography was performed during spinal surgery on two dogs that were suspected of having intramedullary lesions by myelography and magnetic resonance imaging. Ultrasonographically, the pathologic conditions of the spinal canal or cord were adequately imaged during surgery in both dogs. On the basis of ultrasonographic findings, a biopsy was obtained in Patient 1 and removal of the lesion was accomplished in Patient 2. Histopathologic diagnosis was myelomalacia in Patient 1 and spinal nephroblastoma in Patient 2. Intraoperative ultrasonography was demonstrated to be suitable for detecting intradural conditions, and, thus, is valuable for increasing the accuracy of biopsies or completeness of resections of intramedullary lesions.     

Pilot evaluation of a vacuum-assisted biopsy instrument for percutaneous renal biopsy in dogs

Kidney biopsies in dogs are commonly obtained using automated spring-loaded biopsy instruments. Interpretation of biopsies from dogs with glomerular disease requires examination of at least 5-10 glomeruli, with at least two biopsies usually required for full evaluation. The purpose of this study was to compare quality and interpretability of renal biopsies obtained from healthy dogs with a large-gauge, vacuum-assisted biopsy instrument versus two biopsies obtained with a spring-loaded biopsy needle. Twenty dogs were randomized into two groups, and percutaneous, ultrasound-guided renal biopsies were evaluated using standard criteria. There were no significant differences in the number of biopsies that contained renal tissue, cortex, or medulla. Biopsies obtained with either instrument contained an adequate number of glomeruli and an equivalent number of arterioles and severity of tissue compression. Differences included easier penetration of the renal capsule and collection of sufficient tissue for interpretation with only one instrument pass when using the vacuum-assisted device (vs two passes required with the spring-loaded instrument). Before use in client-owned dogs, future studies should evaluate whether these differences are clinically relevant advantages in the diagnostic evaluation of dogs with kidney disease, and determine the prevalence and severity of complications when using this larger gauge device.     

Transitional cell carcinoma of the renal pelvis in two dogs

Transitional cell carcinoma (TCC) of the renal pelvis was found in two dogs, a 7-year-old male English Setter and a 11-year-old female Shetland shepherd. Affected dogs were presented for clinical examination without any specific symptoms but haematuria in case 1 and occurrence of whitish material in the urine of case 2; neoplastic disorders were discovered with ultrasonographic investigation and fine needle aspiration biopsy. Histopathological examination was carried out after nephrectomy and ureterectomy of the affected kidney of both dogs, and confirmed the diagnosis of non-invasive and low grade TCC in case 1 and of infiltrating TCC in case 2. The clinical, gross, cytological and histopathological features of these rare tumours originating from transitional epithelium of the renal pelvis are reported.     

Ultrasound-guided core needle biopsy in dogs with thyroid carcinoma

Currently, a histological diagnosis of highly vascularized canine (c) thyroid carcinoma (TC) is primarily obtained following excisional biopsy (EB) through thyroidectomy. Non-EBs are contraindicated in unresectable invasive cTCs due to their highly vascularized nature, which subsequently, lack histological diagnosis. We hypothesised ultrasound-guided core needle biopsy (UGCNB) to be a safe biopsy technique to obtain an accurate histological diagnosis in unresectable TCs. Nine client-owned dogs with suspected naturally occurring TC, presented for surgical excision, were included. First, a UGCNB was taken from the cervical tumour, followed by EB. Haemorrhage following UGCNB was evaluated preoperatively and once the tumour was surgically exposed by visual inspection and ultrasonography. Histological analysis, including cell organisation, tumour capsular and vascular invasion, and immunohistochemistry were performed and compared between both biopsy specimens (i.e., UGCNB and EB) of the same dog. Pre- and peroperative visual inspection revealed minor, localised haemorrhage, subsequent to the UGCNB, in 7/9 dogs. Histology of the EBs confirmed TC in 8/9 dogs and was inconclusive in 1/9 dogs. Histology of the UGCNBs revealed neoplastic thyroid tissue in 7/9 UGCNBs and was inconclusive in 1/9 UGCNBs. The remaining UGCNB contained no mass related tissue and was, therefore, excluded. Histological parameters (i.e., cell organisation, tumour capsular and vascular invasion) were not concordant between 6/8 included UGCNBs and their respective EB. Immunolabelling for thyroglobulin and calcitonin was concordant between all eight included UGCNBs and their respective EB. The remaining evaluated immunohistochemical markers (i.e., cyclooxygenase-2 [COX-2], P-glycoprotein and vascular endothelial growth factor [VEGF]) were concordant between the included UGCNBs and the EBs in 6/8 dogs. To conclude, UGCNBs can be safely obtained in suspected cTCs and enable a reliable diagnosis of the thyroid origin, thyroid cell origin and potential therapeutic markers such as COX-2, P-glycoprotein and VEGF. Subsequently, UGCNB enables clinicians to establish an individually tailored treatment plan in dogs with unresectable TC.     

URETERAL DIVERTICULA IN TWO DOGS

We describe ureteral diverticula in two dogs and briefly review the related literature. The diagnosis of this condition is radiographic and based on the excretory urographic observation of multiple ureteral outpouchings. Pathologically, ureteral transitional cell hyperplasia and mucinous metaplasia result in submucosal proliferation of the urothelium and the formation of crypts and small cysts. Ureteral diverticulosis in humans is associated with an increased risk of urothelial malignancies, such as transitional cell carcinoma of the urinary bladder. Clinically, both dogs were older, small breed neutered females. Both had a history of chronic urinary obstruction. One dog died during surgery to remove an adrenal mass, and the other was euthanized at the owner's request because of an inoperable bladder neoplasm. Histopathologic diagnosis of ureteral lesions confirmed the radiographic diagnosis of ureteral diverticula in both dogs.     

Subepidermal bullous dermatosis due to topical corticosteroid therapy in dogs

Six adult dogs were presented with an unusual bullous dermatosis affecting the glabrous skin of the ventral abdomen and medial thighs. Clinically, flaccid bullae were accompanied by erythema, ulceration, haemorrhage and hyperpigmentation in four of six dogs; the remaining two dogs had thin skin without grossly apparent bullae. Histologically, subepidermal bullae and clefting, vascular proliferation and dilatation (phlebectasia), and alteration in the density and staining of superficial dermal collagen were seen in all dogs. In all cases, corticosteroid-containing topical products had been applied to the affected areas prior to the development of the dermatosis; skin lesions resolved when topical corticosteroids were withdrawn. Follow-up biopsy of three dogs showed resolution of the previously abnormal collagen and subepidermal clefting. Residual lesions included phlebectasia, comedones and hyperpigmentation. The authors postulate that subepidermal clefting was due to local, corticosteroid-induced skin fragility. This is the first report, to our knowledge, of bullous skin disease in dogs resulting from topical corticosteroid therapy.     

ULTRASONOGRAPHIC EXAMINATION OF CERVICAL MASSES IN THE DOG AND CAT

The ultrasonographic appearance of clinically undifferentiated neck masses for which a definitive diagnosis was eventually obtained in nineteen dogs and one cat is presented in this report. Multiple lesions were seen ultrasonographically in 4 dogs and no cervical abnormalities were seen in 2 dogs resulting in 22 lesions in 20 annuals. Of 7 benign lesions, there were 2 patients with reactive lymph nodes from a regional inflammatory process, and 1 patient each with primary pyogranulomatous lymphadenitis, arteriovenous malformation, foreign body granuloma, cellulitis, and hematoma. Of 15 malignant lesions, 7 were thyroid carcinomas, 3 were lymphomas with submandibular and cervical lymph node enlargement, 3 were lymph node enlargements associated with regional metastasis of malignant tumors, one was a leiomyosarcoma and one was a carotid body tumor. One dog with a diffuse soft tissue swelling of the ventral cervical region had only slight asymmetry of the thyroid lobes on ultrasound examination and no abnormalities of the neck at post mortem. A second dog examined with ultrasound 4 months after surgical removal of a carotid body tumor had no evidence of tumor recurrence. Ultrasonographic examination provided information regarding the character of the lesions, the tissue or organ of origin, and invasion into other anatomic structures. Ultrasound examination in conjunction with fine needle or tissue biopsy provided a definitive diagnosis in those animals in which biopsies were performed.     

NEEDLE-TRACT IMPLANTATION FOLLOWING US-GUIDED FINE-NEEDLE ASPIRATION BIOPSY OF TRANSITIONAL CELL CARCINOMA OF THE BLADDER, URETHRA, AND PROSTATE

Localized tumor implantation of the ventral abdominal wall was found at 2, 5, and 8 months following percutaneous ultrasound-guided fine-needle aspiration biopsy (FNAB) of transitional carcinoma of the bladder, urethra, or prostate in 3 dogs. To our knowledge this complication has not been reported in dogs following FNAB. Despite the rarity of needle-tract implantation, the potential for this complication with transitional cell carcinomas is apparently not negligible and warrants consideration. We recommend traumatic urethral catheterization to obtain a cytologic diagnosis of potential transitional cell carcinomas of the lower urinary tract or prostate whenever possible until more information becomes available. However, needle-track implantation is so rare that it should not influence the decision to perform a percutaneous FNAB if the urethra cannot be catheterized.     

Expression of cyclooxygenase-2 in transitional cell carcinoma of the urinary bladder in dogs

OBJECTIVE: To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the urinary bladder epithelium of clinically normal dogs and in transitional cell carcinoma cells of dogs. ANIMALS: 21 dogs with transitional cell carcinoma of the urinary bladder and 8 dogs with clinically normal urinary bladders. PROCEDURE: COX-1 and COX-2 were evaluated by use of isoform-specific antibodies with standard immunohistochemical methods. RESULT: COX-1, but not COX-2, was constitutively expressed in normal urinary bladder epithelium; however, COX-2 was expressed in neoplastic epithelium in primary tumors and in metastatic lesions of all 21 dogs and in new proliferating blood vessels in 3 dogs. Also, COX-1 was expressed in the neoplastic cells. CONCLUSIONS AND CLINICAL RELEVANCE: Lack of expression of COX-2 in normal bladder epithelium and its substantial expression in transitional cell carcinoma cells suggest that this isoform may be involved in tumor cell growth. Inhibition of COX-2 is a likely mechanism of the antineoplastic effects of non steroidal antiinflammatory drugs.     

ULTRASONOGRAPHIC APPEARANCE OF URETHRAL TRANSITIONAL CELL CARCINOMA IN TEN DOGS

The mucosal margin of the urethra is best assessed by positive contrast urethrography, but ultrasonography offers complementary information such as urethral wall thickness and size of medial iliac lymph nodes. Ultrasonography of the urethra is quick, noninvasive and does not require sedation or general anesthesia. In patients with complete urethral obstruction, ultrasonography may be the only way to image the urethra. Twelve dogs which were presented to Tufts University School of Veterinary Medicine with clinical signs referable to the urinary bladder, urethra or vagina were examined ultrasonographically. Seven were neutered females and five were neutered males. Each dog had a hyperechoic, nonshadowing line at the epithelial surface of the proximal urethra. In the seven female patients and one of the males, the urethral wall was also thick and hypoechoic to surrounding tissue. In the other males, the urethral epithelial changes were at the level of the prostate, and the limits of the urethra were not visible. In six dogs, the urethral change was the only abnormality seen, while in six, bladder wall, bladder luminal and/or prostatic parenchymal changes were also detected. Three patients had hydronephrosis, and one had enlarged medial iliac lyumph nodes. Biopsies were obtained via suction with urinary catheterization (n = 6), exploratory celiotomy (n = 3), urethroscopy (n = 2), or at post-mortem (n = 1). A histopathologic diagnosis of urethral transitional cell carcinoma was obtained in ten dogs. The ultrasonographic appearance was not pathognomonic for transitional cell carcinoma, as one dog with transitional cell dysplasia and one dog with severe ulcerative and necrosupperative cystitis and urethral stricture had similar findings.     

Effect of sample quality on the sensitivity of endoscopic biopsy for detecting gastric and duodenal lesions in dogs and cats

Background: The quality of histopathology slides of endoscopic biopsies from different laboratories varies, but the effect of biopsy quality on outcome is unknown.
Hypothesis: The ability to demonstrate a histologic lesion in the stomach or duodenum of a dog or cat is affected by the quality of endoscopic biopsy samples submitted. More endoscopic samples are needed to find a lesion in poor-quality tissue specimens.
Animals: Tissues from 99 dogs and 51 cats were examined as clinical cases at 8 veterinary institutions or practices in 5 countries.
Methods: Histopathology slides from sequential cases that underwent endoscopic biopsy were submitted by participating institutions. Quality of the histologic section of tissue (inadequate, marginal, adequate), type of lesion (lymphangiectasia, crypt lesion, villus blunting, cellular infiltrate), and severity of lesion (normal, mild, moderate, severe) were determined. Sensitivity of different quality tissue samples for finding different lesions was determined.
Results: Fewer samples were required from dogs for diagnosis as the quality of the sample improved from inadequate to marginal to adequate. Duodenal lesions in cats displayed the same trend except for moderate duodenal infiltrates for which quality of tissue sample made no difference. Gastric lesions in dogs and mild gastric lesions in cats had the same trend, whereas the number of tissue samples needed to diagnose moderately severe gastric lesions in cats was not affected by the quality of tissue sample.
Conclusions and Clinical Importance: The quality of endoscopically obtained tissue samples has a profound effect on their sensitivity for identifying certain lesions, and there are differences between biopsies of canine and feline tissues.     

Ureterocolonlc Anastomosis in Ten Dogs with Transitional Cell Carcinoma

Ureterocolonic anastomosis (UCA) was performed in 10 dogs with transitional cell carcinoma of the urinary bladder trigone or the urethra, or both. All grossly visible tumor was excised. All of the dogs recovered from anesthesia and surgery and had anal continence with no urine leakage. One dog died of undetermined causes 7 days after surgery. Nine dogs survived 1 to 5 months. The owners of eight of the dogs considered their dog's quality of life to be acceptable. Four dogs were euthanatized because of neurologic disease, three of which also had nausea and vomiting. The neurologic and gastrointestinal signs may have been caused by hyperammonemia, metabolic acidosis, and uremia. Blood ammonia levels were elevated in two dogs with neurologic signs. Hyperchloremic metabolic acidosis that was reversible with bicarbonate therapy was diagnosed in five dogs. All of the dogs were azotemic because of intestinal recycling of urea. Serum creatinine concentrations increased in four dogs after surgery. Drug-induced renal disease may have developed in two dogs. Pyelonephritis developed in five kidneys, two of which had outflow obstruction and two had bilateral hydroureteronephrosis before the UCA. In this small number of dogs, surgical excision of transitional cell carcinoma was not curative with six dogs having confirmed metastatic lesions at the time of death.     

COMPUTED TOMOGRAPHY-GUIDED FINE-NEEDLE ASPIRATE AND TISSUE-CORE BIOPSY OF INTRATHORACIC LESIONS IN THIRTY DOGS AND CATS

Medical records and computed tomography (CT) images were reviewed retrospectively for 30 animals (27 dogs, two cats, one cougar) in which CT-guided intrathoracic fine-needle aspirates (FNA) (12), core biopsies (10) or both (8) were performed. Sample interpretation was listed as diagnostic or nondiagnostic and nonneoplasia or neoplasia. Diagnostic results were inconclusive in 35% FNA and 17% biopsies. FNA and biopsy interpretations were in agreement in seven patients, one nonneoplasia, and six neoplasia. A clinical diagnosis was made in 65% FNA and 83% biopsies. When 18 patients with confirmed diagnoses were used, overall accuracy for diagnosis was 92% for FNA and biopsy and the sensitivity for neoplasia was 91% using fine needle aspirate and 80% using biopsy. Complications seen on CT images were noted in 43% of patients, four pneumothorax, five pulmonary hemorrhage, and four with both. No clinical manifestations were noted and treatment was not necessary. Significant correlation was noted between complications and penetration of aerated lung, but not with lesion location, type of disease, method of sampling, width of mass and depth of aerated lung penetrated. CT-guided sampling is relatively safe and useful in the diagnosis of intra-thoracic lesions, especially neoplasia. FNA samples are nondiagnostic more often than biopsy samples. Sub-clinical pneumothorax and hemorrhage are common when aerated lung is penetrated.