Urinoma (para-ureteral pseudocyst) as a consequence of trauma in a cat

A two-year-old cat was involved in a road traffic accident. Survey abdominal radiographs and urinary function were considered unremarkable. Six weeks later the cat presented with a palpable dorsal abdominal mass. Radiography revealed a soft tissue opacity mass caudal to the right kidney. Ultrasonography revealed a cyst-like structure with moderately echogenic contents, and right-sided hydronephrosis. There was no excretion of contrast medium from the right kidney after intravenous urography. Surgery revealed a disrupted right ureter adherent to the retroperitoneal mass. The mass contained serosanguineous fluid consistent with extravasated urine. Ureteronephrectomy was performed. The majority of the mass was excised and the cavity ablated. Histopathology of the excised tissue revealed a thick fibrous wall with no epithelial lining, consistent with a urinoma, which is thought to have developed as a consequence of ureteral trauma. The cat was clinically well three months postoperatively.     

Ultrasound-guided percutaneous antegrade pyelography with computed tomography for the diagnosis of spontaneous partial ureteral rupture in a dog

A 10-year-old spayed female dalmatian dog developed acute vomiting and abdominal pain. Ultrasound examination of the abdomen showed right hydronephrosis and proximal ureter dilation with mild retroperitoneal free fluid. Computed tomography (CT) of the abdomen confirmed the ultrasonographic findings and revealed, additionally, a right ureteral stone. Spontaneus rupture of the right ureter was confirmed with CT post ultrasound-guided percutaneous antegrade pyelography. Pyeloureteral rupture and the presence of a ureteral stone were confirmed at surgery.     

Bilateral hydronephrosis secondary to anticoagulant rodenticide intoxication in a dog

Objective: To describe an unusual site of hemorrhage in a case of anticoagulant rodenticide toxicity. Case summary: A dog treated for Brodifacoum anticoagulant rodenticide intoxication was referred for treatment of thrombocytopenia and dysuria. Sonographic examination revealed a large blood clot within the urinary bladder, extending proximally along both ureters, and a bilateral hydronephrosis. In this dog, management of the vitamin K₁‐dependent coagulopathy was unusually complicated by uremia and thrombocytopenia. New information provided: This is the first reported case of hydronephrosis secondary to anticoagulant rodenticide intoxication in a dog.     

Right ventricular rupture after lateral thoracotomy for removal of rib-associated telangiectatic osteosarcoma in a dog

Objective – To describe a case of a focal right ventricular rupture following removal of a rib-associated telangiectatic osteosarcoma (TOS) in a dog.
Case Summary – A 2-year-old spayed female mixed-breed dog, weighing 20 kg, was presented in compensated hypovolemic shock due to active bleeding into the thoracic cavity. The dog was stabilized with appropriate fluid administration. Subsequent computed tomographic examination revealed a large mineralized mass originating from the body of a rib and displacing the heart. Two days after surgical removal of this mass, focal right ventricular rupture occurred and the dog died. The mass was later identified as a TOS.
New or Unique Information Provided – Although hemothorax secondary to TOS has been described previously, this report describes for the first time, spontaneous focal right ventricular rupture as a rare complication of thoracotomy and rib resection for the removal of a rib-associated, intrathoracic TOS.     

FAT NECROSIS SIMULATING RECURRENT NEOPLASIA FOLLOWING EXTERNAL BEAM RADIOTHERAPY IN A DOG

A 4.5-year-old neutered male dog was diagnosed with incompletely excised well-differentiated lymphangiosarcoma in the right inguinal subcutaneous region. The mass had metastasized to the right hypogastric and medial iliac lymph nodes. Surgery followed by definitive radiation therapy was administered to the primary site and the sites of metastasis. The dog had a complete response to radiotherapy, and minimal acute side effects. Doxorubicin was administered after radiotherapy. Approximately 4 months following radiation therapy, the dog developed a mass, presumed recurrent tumor, in the original site. In a biopsy only steatitis and fibrosis were found. The mass continued to grow and conservative surgical excision was elected. Histopathologically the diagnosis was fat necrosis and steatitis, with a microscopic focus of lymphangiosarcoma. Fat necrosis is an uncommon sequelum to breast irradiation in people and also appears to be rare in animals. Fat necrosis should be considered as a differential diagnosis when recurrent tumor is suspected in a previously irradiated subcutaneous site in a dog.     

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.     

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.     

Suspected disseminated histiocytic sarcoma in a 3-year-old Perro de Presa Canario dog

A 3-year-old intact male Perro de Presa Canario dog was presented with acutely inflamed and edematous right hind limb, scrotum, prepuce, and an enlarged left carpus. Two weeks later the dog returned with weight loss, draining tracts in the right hind limb, dermal nodules, a palpable abdominal mass, and uveitis in the left eye. The dog succumbed to his illness 2 days later and a widely disseminated round cell tumor compatible with histiocytic sarcoma was diagnosed following postmortem examination.     

SONOGRAPHIC APPEARANCE OF RENAL NEOPLASIA IN THE DOG

Eight dogs with renal neoplasia were radiographically and sonographically examined. An enlarged, nonopacified kidney was seen on the excretory urogram in four dogs, but differentiation between a solid mass or severe hydronephrosis was not possible. The excretory urogram suggested an avascular lesion in one kidney, but differentiation between solid or cystic disease was not possible. Renal neoplasia was diagnosed in two dogs by excretory urography. Radiographic examination suggested splenic neoplasia in one dog. Solid masses were sonographically diagnosed in all dogs. A metastatic lesion was sonographically diagnosed in the opposite kidney of one dog that was missed on the radiographic examination. Ultrasonography com-plemented radiography as a diagnostic modality in eliciting additional information on renal disease. Sonograms did not allow determination of tumor cell type or whether the tumor was benign or malignant.     

Zoledronic acid for the treatment of appendicular osteosarcoma in a dog

A 10-year-old male intact Corso dog was referred for lameness and for a large neoplasm affecting the right foreleg. Physical examination of the patient revealed a 5 × 5 × 3 cm mass in the distal right foreleg. Histopathology was consistent with a diagnosis of appendicular osteosarcoma. The staging process found no evidence of metastasis. Because of the large size of the patient, the owners elected to treat their dog with antiresorptive therapy. The patient was treated with an infusion of zoledronic acid every 28 days. The tumour remained stable for 16 months and the lameness of the dog greatly improved. At that time, the patient returned for evaluation of a large rapidly growing prescapular mass. Biopsy confirmed lymph node metastasis and the dog was euthanased. Zoledronic acid showed remarkable palliation in our patient and possibly anti-tumour action and warrants further investigation.     

Myxosarcoma in the eye and brain in a dog

A male mixed breed dog of unknown age was presented with sudden onset of blindness and a slightly exophthalmic right eye. Ophthalmoscopically, a spherical, pinkish mass protruding from the region of the optic disc into the vitreous was seen in the right eye. Ultrasound and computer tomography demonstrated an extension of the mass into the right retrobulbar space, continuing intracranially to the optic chiasm. Cytologic findings, obtained by ultrasound-guided fine needle aspiration from the retrobulbar space, were consistent with myxosarcoma. On the basis of these findings of a well-delineated mass in the brain stem area, irradiation was planned as the therapy of choice. The dog was treated under general anesthesia using a proton beam at the Paul Scherrer Institute (PSI, Villigen, Switzerland). A curative protocol (56 Gy in 16 fractions over 4 weeks, 3.5 Gy/fraction) was used. Twenty-seven days post radiation therapy the dog was euthanized, as clinical symptoms progressed. Enlargement of the intracranial tumor was seen on a CT study repeated on the day of euthanasia. A gross pathologic and histologic examination were performed and confirmed the diagnosis of a myxosarcoma involving the eye, retrobulbar space of the right side, and the optic chiasm. Post-mortem examination failed to identify any abnormalities or metastases elsewhere in the body.     

PROBABLE TRIGEMINAL NERVE SCHWANNOMA IN A DOG

A 7-year-old male Husky dog developed atrophy of the right masseter muscle and pruritis of the right side of the face. A myogenic origin was excluded using muscular biopsy. Electrophysiologically, there was involvement of the motor and sensory fibers of the trigeminal nerve, suggesting a lesion located between the brainstem and the trigeminal ganglion. On MRI examination, a nodular mass was detected in the right caudal fossa. This mass was characterized by intense enhancement after injection of contrast medium. Because of the progressive clinical signs, electrophysiology, and MRI results, a presumptive diagnosis of a trigeminal nerve schwannoma was made. The animal's condition improved slightly with corticosteroids. The dog underwent euthanasia 3 months after initial presentation. Necropsy was not performed.     

Intestinal choristoma in the midcervical region of a dog

A 5-year-old, neutered male, mixed-breed dog was evaluated for a fluctuant mass in the right midcervical region. The mass recurred following aspiration of its contents and after removal of the right sublingual and mandibular salivary glands. The lateral midcervical location of the mass and the serous nature of the fluid within the mass were inconsistent with a salivary mucocele. Excisional biopsy was curative and revealed an intestinal choristoma.     

IMAGING DIAGNOSIS—HYPEROSTOSIS ASSOCIATED WITH MENINGIOMA IN A DOG

A 5-year-old neutered male Beagle mix dog had a 5-day history of generalized tonic-clonic seizures. Before the seizures, the dog had a 1-2-month history of progressive right hemiparesis. In computed tomography images, a presumed extraaxial mass with hyperostosis and destruction of the skull covering the mass were identified. Surgical excision was performed and the histopathologic diagnosis was meningioma. Hyperostosis is frequently associated with feline meningioma, but this report documents that hyperostosis may also occur secondary to meningioma in the dog.     

Femoral compartment syndrome due to haemangiosarcoma in the semimembranosus muscle in a dog

A five-year-old, entire male German shepherd dog was presented to the Veterinary Teaching Hospital-Koret School of Veterinary Medicine because of an acute, painful swelling of the right thigh and severe lameness of two-weeks duration. On physical examination, a firm and painful mass was detected in the hamstring region. Radiography and ultrasonography revealed a soft tissue mass, with a 250 cc fluid accumulation craniomedial to it. Intracompartmental pressure measurement with a Wick catheter demonstrated significantly elevated pressure within the right caudal femoral compartment (25 to 28 mmHg compared with 5 to 7 mmHg in the unaffected leg). Surgical exploration of the area was undertaken, fasciotomy and mass excision were performed, and resolution of the clinical signs was achieved. The mass was identified by histopathology results as haemangiosarcoma. Two and a half months after surgery, which was followed by adjunct chemotherapy (doxorubicin), the dog was readmitted with a subcutaneous mass in the same area, although he was not lame at this time. Radiographs of the thoracic cavity demonstrated widely disseminated metastases in the lungs. At that point, the owner elected to have the dog euthanased.     

Cerebellar myxoid type meningioma in a Shih Tzu dog

A 6-year and 9 month-old, male, Shih Tzu dog showed ataxia and trembling. By MRI examination, a mass (1 cm) was found in the right cerebellum. As the dog did not respond to radiation therapy, and showed a rise of intracranial pressure, he was euthanized. The cerebellar mass was soft and hemorrhagic. Histologically, the mass contained vimentin-positive spindle- or polyhedral-shaped cells arranged in a cord-like pattern. Mucinous materials were observed in the intercellular spaces. Ultrastructural examination revealed cell processes, microtubule-like structures and desmosomes. The case was diagnosed as myxoid type meningioma.     

Uterine Leiomyoma in a Spayed Poodle Bitch: A Case Report

A 16‐year‐old, spayed, female poodle dog was presented for evaluation of tenesmus, with the ability to attract male dogs and a willingness to mate. The dog had undergone an ovariohysterectomy when it was 7 years old. Haematological and serum biochemistry analyses demonstrated leucocytosis and a mild uraemia. A vaginal smear was predominantly made up of superficial cells, accounting for at least 80% of the cells. Abdominal ultrasonography revealed a heterogeneous multicystic mass at the caudal abdomen and two masses with anechoic areas adjacent to the caudal pole of each kidney. A midline exploratory laparotomy identified a uterine mass and residual ovaries that were surgically excised. Histopathological examination of the mass demonstrated that it was a leiomyoma. The left ovary had a cystic structure and the right ovary had a papillary cystic adenoma. Seven months after the surgery, the owner reported that the dog was clinically normal. To the authors’ knowledge, this is the first reported case of a uterine leiomyoma after an incomplete ovariohysterectomy in the dog.     

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.