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 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.     

Primary cardiac spindle cell tumor in a dog

An adult Labrador retriever dog was presented with respiratory signs and heart murmur. Echocardiography and thoracic radiographs revealed a heart base mass infiltrating the left atrial wall. Microscopically, neoplastic tissues consisted of spindle cells and abundant extracellular matrix. Based on histochemical stain and immunohistochemistry, a diagnosis of primary cardiac sarcoma was made.     

Chemotherapy of synovial cell sarcoma in a dog

A synovial cell sarcoma of the tarsus in a 6-year-old dog was treated with doxorubicin HCl and cyclophosphamide. The tumor regressed after treatment. There was no recurrence 3 years after initiation of treatment. Previously, synovial cell sarcoma has not been reported to be responsive to chemotherapeutic agents, and the treatment of choice has been amputation.     

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.     

Spindle cell sarcoma in the kidney of a dog

A spindle cell sarcoma involving the left kidney was diagnosed in a 14-year-old male Basenji. Radiography and ultrasonography were used to define the extent and location of the mass. Metastatic disease was not detected. An 8 x 5-cm mass, involving the left kidney, was resected by performing nephroureterectomy. Signs of metastasis were not detected at 3 and 6 months after surgery. Shortly after the 6-month examination, the dog was euthanatized because of perceived signs of pain attributable to cervical disk disease. Postmortem examination was not performed. Histologic examination consisted of use of hematoxylin and eosin, Masson trichrome, and van Gieson stains, and 4 immunoperoxidase techniques. On the basis of the histologic findings, the final diagnosis was spindle cell sarcoma, with the 2 most likely possibilities being leiomyosarcoma and fibrosarcoma.     

Primary pulmonary spindle cell tumour (haemangiopericytoma) in a dog

Haemangiopericytoma is a soft tissue sarcoma believed to originate from pericytes. These tumours are commonly located on the skin and subcutaneous tissue of dogs and are most commonly found on the limbs. To the authors' knowledge, primary lung haemangiopericytomas have not been previously described in dogs. This case report describes the diagnostic evaluation and treatment of a primary haemangiopericytoma of the lung in a 10-year-old male, neutered, Siberian husky dog. Staging of the tumour was performed using a computed tomography scan of the thorax and a computed tomography-guided fine-needle aspiration biopsy of the lesion. Treatment was a right caudal lobectomy from a right lateral approach. No regional lymph node changes were noted on computed tomography or intraoperative assessments. Histopathology confirmed a spindle cell tumour that stained positive for vimentin and negative for desmin and S-100.     

Mast cell sarcoma of the larynx in a dog: a case report

An 8-year-old, spayed, female miniature poodle was presented to the University of Pennsylvania Veterinary Hospital (UPVH) with signs of mild respiratory distress related to increasing laryngeal obstruction. The dog was found to have a unicentric mast cell sarcoma involving the larynx, with tumour infiltration of the tissues between the thyroid and arytenoid cartilages as well as subglottic narrowing. Treatment and differential diagnosis are described.     

Synovial sarcoma in a dog.

A 6.5-year-old, female Saint Bernard had a slowly growing tumor of the right tibiotarsal joint. Radiographically, bone surrounding the tumor was not involved. Subtotal surgical resection was undertaken. The tumor was classified histologically as a synovioma. Within 6 months, the tumor recurred locally and invaded the soft tissue proximal to the tibiotarsal joint. Eighteen months after initial examination, there was widespread right tibial invasion and pulmonary metastasis. The dog was euthanatized. The final histopathologic diagnosis was synovial sarcoma.     

Metastatic transmissible venereal sarcoma in a dog

An adult male dog with large penile sheath and serosanguineous exudate from the preputial orifice and a cutaneous fistula in the right inguinal area was examined. Necropsy revealed tumor masses on the penis and prepuce, in superficial inguinal and external iliac lymph nodes, and in the liver. Histopathologic diagnosis of the tumor was confirmed by transplantation studies.     

Use of hyperthermia and radiotherapy in treatment of a large mast cell sarcoma in a dog

A large infiltrating mast cell sarcoma in a dog, which had been refractory before surgical excision, was controlled 2 months after completion of a combined radiotherapy and hyperthermia regimen. Treatment resulted in rapid tumor necrosis and resultant ulceration of adjacent skin. Ulceration was transient, resolving concurrently with tumor control. Radiation was administered as 3.5-Gy fractions 3 times/week, resulting in a total dose of 45.5 Gy in 13 treatments. Hyperthermia (44 C for 30 minutes) was given 4 to 5 hours after radiotherapy, once a week during the first 3 weeks of treatment.     

Multifocal cutaneous histiocytic sarcoma in a young dog and review of histiocytic cell immunophenotyping

A 9‐month‐old male Great Dane had progressive generalized nodular dermatopathy for several months. There were > 100 raised, alopecic, firm, painful nodules throughout the skin. Aspirates from several lesions yielded moderate numbers of irregularly round or polygonal to spindle‐shaped cells with mild to moderate anisocytosis and few inflammatory cells, and the cytologic interpretation was proliferation of mesenchymal or histiocytic cells. On histopathologic examination, nodules were composed of densely packed sheets of round to spindle‐shaped cells with mild anisokaryosis and low mitotic activity. Multifocal histiocytic sarcoma with a spindle‐cell pattern was diagnosed based on morphologic features and intense expression of CD18. Additional immunophenotypic analysis on frozen sections of tissue confirmed the diagnosis of histiocytic sarcoma; expression of CD18, CD45, CD1a, CD11b, and CD11c, limited expression of Thy‐1 (CD90) and CD80, and lack of expression of CD4, CD11d, and CD86 indicated that the cells were likely interstitial dendritic cells; a review of reactive and neoplastic dendritic cells is provided. Based on staging, internal organs were not affected. Sequential treatment with lomustine and doxorubicin failed to prevent progression of the cutaneous lesions, and the dog died 3 months after initial diagnosis. At necropsy, a focus of neoplastic cells was present in one lymph node, but except for skin other organs were not involved. The clinical presentation of histiocytic sarcoma may be unusual, and neoplastic cells may lack overt features of malignancy on cytologic and histopathologic examination. In some instances, immunophenotyping is required to differentiate histiocytic sarcoma from other histiocytic disorders.     

Meningeal sarcoma mimicking a sciatic neuropathy in a dog

A 5-year-old Golden Retriever presented for lameness evaluation and removal of a dynamic compression plate on the left femur exhibited neurologic signs compatible with a left sciatic peripheral neuropathy. Radiographs revealed a healed fracture of the left femur and a slightly narrowed intervertebral disc space with ventral spondylosis at T_12–13. An EMG demonstrated fibrillation potentials and positive sharp waves in the left hind limb muscles innervated by the peroneal nerve. Surgery was performed to remove the bone plate and explore the left sciatic nerve. The proximal 3 cm of the left peroneal nerve was surrounded by thick fibrous connective tissue and its diameter was smaller than the more distal segment. The dog's condition remained static for 4 weeks and then gradually progressed to paraparesis in 2 weeks. A neurologic examination at that time indicated a caudal lumbar spinal cord lesion and a myelogram confirmed an intradural mass at the level of the 4th lumbar vertebra. The dog was destroyed and a necropsy performed. The histologic diagnosis was meningeal sarcoma.