Right-sided ureteral hemangiosarcoma in a paraplegic dog.

BACKGROUND: This study aims to describe a rare case of primary ureteral hemangiosarcoma, in which surgical intervention preserved the kidney and ureter after tumor removal. CASE PRESENTATION: A 13-year-old, neutered male dog, weighing 14 kg, mixed-breed, presented with apathy, anorexia, acute-onset vomiting, and abdominal discomfort during the physical examination. Ultrasonography and pyelography revealed a right-sided dilation of the renal pelvis and ureter due to complete obstruction in the middle third of the ureter. A mass obstructing the lumen of the right ureter was completely resected, and ureteral suturing was performed, preserving the integrity of the involved structures. Histopathology confirmed primary ureteral hemangiosarcoma. Due to the local and non-invasive nature of the mass, chemotherapy was not initiated. The patient's survival was approximately two years, and normal renal function was preserved throughout this period. CONCLUSIONS: Considering this type of tumor in the differential diagnosis of upper urinary tract obstructive disorders. Furthermore, the preservation of the ureter and kidney is a suitable therapeutic option after surgical resection of non-invasive tumors.

The cytologic and histologic diagnosis of ureteral fibroepithelial polyp in a dog.

A 6-year-old, intact male, brindled, 30-Lb English Bulldog presented to the Purdue University Veterinary Teaching Hospital with a recurrent history of hematuria, periuria, and lethargy that responded temporarily to antibiotic therapy. The work-up included a complete blood count, serum biochemical profile, complete urinalysis, diagnostic imaging (abdominal radiographs and ultrasound with contrast urography), and exploratory laparotomy. The diagnostic imaging findings and subsequent exploratory revealed a unilateral, intraluminal, right-sided, 3-cm ureteral mass extending from the proximal ureter into the renal pelvis. Subsequently, a unilateral right-sided ureteronephrectomy followed by biopsy with cytopathology/cytology (impression smears) and histopathology of the ureteral mass was performed. The cytopathologic interpretation was benign mesenchymal proliferation with mildly atypical urothelial cells. The association of this mass with vascular tissue and a benign nuclear appearance on cytology is similar to reports of fibroepithelial polyps (FEPs) and myxomatous tumors. Histopathology diagnosed the mass as an FEP. Cytopathology proved useful in the presumptive diagnosis of this benign urothelial polyp. To the authors' knowledge, this is the first report using cytopathology to depict and characterize FEPs in veterinary and human medical literature.

Use of radiography, ultrasonography, and computed tomography in the diagnosis of a pyogranulomatous ureteral mass in a cat.

An 8-year-old, spayed female, domestic short haired cat, with diabetes mellitus, was presented to the University of Florida Veterinary Medical Center for an acute onset of vomiting and inappetence. Abdominal radiographs showed mild retroperitoneal effusion and asymmetric left-sided renomegaly. Subsequently, on abdominal ultrasound, a hypoechoic left ureteral mass with left hydronephrosis and hydroureter was identified. An abdominal computed tomography revealed a heterogeneously contrast-enhancing mass circumferentially surrounding the mid to distal left ureter, mild retroperitoneal effusion, left-sided hydronephrosis and hydroureter, and a distally located ureteral calculus at the level of the ureterovesicular junction. The patient was diagnosed with left-sided pyogranulomatous ureteritis via surgical biopsy and histopathology.

Multimodality imaging of primary ureteral hemangiosarcoma with thoracic metastasis in an adult dog.

A 12-year-old spayed female standard Poodle was presented for investigation of severe hematuria. Abdominal ultrasound and thoracic and abdominal computed tomography identified severe hydronephrosis due to an obstructive ureteral mass with no evidence of metastasis. Histological examination after nephrectomy and ureterectomy confirmed an obstructive ureteral hemangiosarcoma. Forty days after surgery, the dog was presented with severe dyspnea. Survey radiographs of the thorax revealed a severe diffuse nodular interstitial pattern. Postmortem histological examination revealed pulmonary metastasis of hemangiosarcoma.

Primary ureteral leiomyosarcoma in a dog.

CASE DESCRIPTION: A nearly 6-year-old female spayed Labrador Retriever was presented for acute abdominal pain and lethargy. The dog had no previous health concerns apart from occasional episodes of urinary incontinence in the 2 months prior to presentation. A retroperitoneal mass involving the right ureter was found during the investigations. Serum urea was mildly elevated, but the serum creatinine was within the normal range. No distant metastases were detected. A right ureteronephrectomy was performed. The ureteral mass was confirmed as a leiomyosarcoma and completely excised. The kidney was histologically normal. Unfortunately, during a routine 3-month postoperative assessment, a recurrent mass at the previous retroperitoneal surgical site was confirmed by biopsy to be a leiomyosarcoma. Courses of doxorubicin and chlorambucil were given, but failed to halt the progression of the recurrent mass. The dog was euthanised 5.5 months postoperatively because of poor quality of life. CLINICAL RELEVANCE: Ureteral leiomyosarcoma should be on the differential diagnosis list for a retroperitoneal mass, possibly causing severe abdominal pain with minor clinical signs associated with the urinary tract. This dog in this reported case of ureteral leiomyosarcoma had a short survival time, despite complete surgical excision and chemotherapy, because of local recurrence.

Iatrogenic tumor seeding after ureteral stenting in a dog with urothelial carcinoma.

A 5 yr old castrated male miniature dachshund presented with clinical signs attributable to carcinoma involving the bladder neck and prostate. On day 84 following diagnosis, the dog developed bilateral ureteral obstruction and ureteral stenting was attempted. The stents were inserted in a normograde fashion via percutaneous puncture of the dilated renal pelvises. Two wk later, the dog developed nodules at both sites of renocentesis. En block resection of the masses was performed, and histologic examination confirmed that the masses were urothelial carcinoma, likely caused by iatrogenic tumor seeding. Ureteral stenting is a useful technique to relieve malignant ureteral obstruction; however, risk of iatrogenic tumor seeding must be considered.

Bilateral ureteral obstruction in a cat due to a ureteral transitional cell carcinoma.

A 15-year-old cat was presented with a history of lethargy and vomiting. Serum biochemistry revealed severe azotemia. Ultrasonography revealed a small left kidney and hydronephrosis of the right kidney. There was an abdominal mass between the kidneys. Necropsy revealed a mass circumflexing both ureters and histopathology confirmed a diagnosis of transitional cell carcinoma.

Primary ureteral giant cell sarcoma in a Pomeranian.

An 8-year-old male neutered Pomeranian dog was presented to the Veterinary Teaching Hospital at Oregon State University for surgical treatment of hydronephrosis of the left kidney and a left cranial abdominal mass. A primary ureteral mass was found during exploratory surgery, and the mass was resected and ureteral anastomosis was performed. Cytologic evaluation of the mass revealed 3 distinct cell populations, including a large number of multinucleated giant cells, a moderate number of thin spindle-shaped cells, and cohesive clusters of transitional epithelial cells. The cytologic diagnosis was giant cell sarcoma. The diagnosis was confirmed by histologic examination, and immunohistochemical staining was performed. The spindle-shaped cells and multinucleated giant cells were both immunoreactive for vimentin and spindle-shaped cells for S-100. Tumor cells did not express wide-spectrum cytokeratin, broad-spectrum muscle actin, smooth muscle actin, sarcomeric actin, desmin, BLA36, Mac 387, synaptophysin, neuron-specific enolase, glial fibrillary acid protein, or von Willebrand factor. These findings are most consistent with an anaplastic sarcoma with giant cells. This is the first case report of a primary ureteral giant cell sarcoma in a dog.

Use of indwelling, double-pigtail stents for treatment of malignant ureteral obstruction in dogs: 12 cases (2006-2009).

OBJECTIVE: To determine the outcome of minimally invasive ureteral stent placement for dogs with malignant ureteral obstructions. DESIGN-Retrospective case series. ANIMALS: 12 dogs (15 ureters) with ureteral obstruction secondary to a trigonal urothelial carcinoma. PROCEDURES: In all patients, indwelling, double-pigtail ureteral stents were placed by means of percutaneous antegrade needle and guide wire access under ultrasound and fluoroscopic guidance. RESULTS: Stents were successfully placed in all patients. In 11 of 12 patients, percutaneous antegrade access was accomplished. One patient required access via laparotomy because percutaneous access could not be achieved. The median survival time from the date of diagnosis was 285 days (range, 10 to 1,571 days), with a median survival time of 57 days (range, 7 to 337 days) from the date of stent placement. Three complications occurred in 1 patient. Seven patients required concurrent urethral stent placement for relief of urethral obstruction. All animals were discharged from the hospital (median hospitalization time after stent placement, 18 hours [range, 4 hours to 7 days]) with an indwelling, double-pigtail ureteral stent (3 bilateral and 9 unilateral) in place. All stents evaluated 0.25 to 11 months after placement were considered patent. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggested that ureteral stent placement was safe, effective, and well tolerated in patients with malignant ureteral obstructions. Stents could be reliably placed in a minimally invasive manner and remain patent long-term. Ureteral stent placement should be considered as early as possible in patients with neoplasia, prior to the development of permanent renal damage.

Ureteral spindle cell sarcoma in a dog.

A five-year-old, female spayed Labrador retriever was presented for further investigation of an intra-abdominal mass. Abdominal exploration showed a large mass arising from the right ureter and a ureteronephrectomy was performed. Histopathology of the ureteral mass was consistent with a spindle cell sarcoma. The patient recovered well, but five months later was diagnosed with another tumour, this time in her left abdominal wall. The owners decided not to pursue further treatment and euthanasia was performed a month later.

Ureteral sarcoma in a dog.

A ureteral sarcoma was diagnosed in a nine-year-old Weimaraner dog with gross haematuria, severe unilateral hydronephrosis, and hydroureter. Treatment consisted of unilateral nephrectomy and ureterectomy. This case was compared with 14 other ureteral tumours reported in the veterinary literature. Only three previous reports concerned a malignant ureteral tumour. Urinary tract neoplasms mainly involve the bladder and the kidney, and more rarely the urethra. The purpose of this paper is to report a rare case of malignant ureteral tumour in a dog.

Ureteral fibroepithelial polyp in an owl monkey (Aotus nancymae).

Ureteral fibroepithelial polyps are benign mesodermal tumors in humans that occur predominantly in the proximal ureter. During a routine necropsy of a wild-caught, research naïve, adult, male, Aotus nancymae, the left ureter just distal to the renal pelvis contained a pedunculated, lobulated neoplasm with a narrow stalk at the base projecting into the lumen. The left renal pelvis was found to be mildly dilated. The histologic characteristics of the ureteral mass were consistent with a fibroepithelial polyp. To our knowledge, this is the first report describing a ureteral fibroepithelial polyp in a nonhuman primate.

Ureteral fibroepithelial polyp in a dog.

Haematuria in a dog occurred secondarily to a unilateral ureteral fibroepithelial polyp. The diagnostic techniques, gross pathology and histopathological findings of this unusual benign tumour are reported. Complete resolution of clinical signs occurred following ureteronephrectomy.

Ureteral mast cell tumor in a dog.

A 6-year-old, castrated male, mixed-breed dog was diagnosed with partial unilateral ureteral obstruction secondary to a ureteral mass. The ureteral mass was surgically resected, and an ureteroneocystostomy was performed. Histopathology of the ureteral mass was consistent with a poorly differentiated mast cell tumor (MCT). The patient recovered well but was euthanized 5 months postoperatively for central nervous system signs. A choroid plexus tumor was diagnosed during necropsy examination. There was no evidence of recurrence or dissemination of the ureteral MCT. Extracutaneous MCTs are rare in dogs, and primary MCT associated with the urinary tract has not previously been reported in the veterinary literature.

Ureteral fibroepithelial polyps in four dogs.

Four dogs with ureteral fibroepithelial polyps, ranging from 9-12 years of age, are presented in this report. The patients presented with urinary incontinence, urinary tract infection, and/or polydypsia and pollakiuria. All dogs were intact at the time of diagnosis or for the majority of their lives and three were male. Various diagnostic procedures were performed including ultrasonography, contrast radiography, and nuclear scintigraphy. Not all procedures were performed in all patients. Findings included ureteral dilation proximal to the level of an intraluminal mass and ipsilateral hydronephrosis. Unilateral ureteronephrectomy was performed in three dogs with masses in the proximal ureter; ureteral resection and anastamosis was performed in the remaining patient with a mass located in the distal ureter. The same pathologist (RAP) reviewed all four lesions. The lesions appeared polypoid and were attached to the ureteral wall by a thin stalk. Histopathologically, they contained a superficial layer of well-differentiated transitional epithelial cells overlying a prominent fibrovascular stroma with a mild (three dogs) or marked (one dog) degree of lymphoplasmacytic inflammation. This disease may represent a benign neoplasm or a chronic inflammatory reaction and has a good prognosis with surgical removal. Its histopathological characteristics, higher incidence in males, and location more commonly within the upper third of the ureter is remarkably similar to the disease in humans.

Ureterolithiasis and papilloma formation in the ureter of a guinea pig.

A 5-year-old guinea pig with suspected urolithiasis was presented for radiology and ultrasound examinations of the abdomen. Radiographically, an irregular-shaped mineral opacity was detected in the area of the urinary bladder. Ultrasonographically, pyelectasia of the right kidney, hydroureter with an ureterolith cranial to a thickened ureter wall close to the ureterovesical junction, and a thickened urinary bladder wall were detected. Histopathologically, the thickened ureter wall was found to be a papilloma. The ureter calculus consisted of 100% calcite.

An unusual presentation of enzootic bovine leukosis.

A 6-year-old, Holstein x Simmental cow diagnosed with pyelonephritis had increasing difficulty rising and became recumbent, despite treatment with antibiotics. A serological test for the bovine leukemia virus was positive; at necropsy, the left kidney and ureter and the myocardium showed lesions of lymphosarcoma, confirmed by histology.

Globule leukocytes in transitional cell hyperplasia and carcinomas of aged mice.

Globule leukocytes (GLs) infiltrating in transitional cell hyperplasia and carcinomas of aged BDF1 mice were pathologically examined. The intracytoplasmic granules of globule leukocytes showed a variety of reactivity to histochemical staining for polysaccharides and were ultrastructurally composed of homogeneous electron dense material, occasionally containing crystaloids or vesicles. The GL infiltrating in tumor tissue is extremely rare.

Renal dysplasia and benign ureteropelvic polyps associated with hydronephrosis in a foal.

A 4-month-old male Trakehner foal with a history of hematuria, poor growth, and abnormal hair was found to have unilateral hydronephrosis and hydroureter, as determined by ultrasonography and surgical exploration. Nephrectomy and ureterectomy were performed as treatment. Gross examination of the ureter and kidney revealed renal pelvic and ureteral polyps causing obstruction and subsequent hydronephrosis. The histologic features were consistent with renal dysplasia. The polyps and renal dysplasia were likely to be congenital, but the etiopathogenesis is not known. The finding that urinary outflow obstruction can disrupt nephrogenesis and lead to renal dysplasia supports the view that the polyps developed, blocked urine flow, and caused the hydronephrosis and renal dysplasia in the foal.