Histiocytic sarcoma in the tarsus of a cat

A 12-year-old Persian cat was examined for a firm swelling of the right tarsal region and enlargement of the corresponding right popliteal lymph node. Cytologic evaluation demonstrated a population of malignant cells consistent with large cell lymphoma. Necropsy revealed a multi-lobulated subcutaneous mass involving the tarsus with some extension into adjacent deep muscular tissue. Histologically, the mass was composed of round cells with eosinophilic cytoplasm and pleomorphic anisokaryotic nuclei. Evidence of articular and nodal infiltration by these cells was observed. Differential diagnoses included synovial sarcoma and histiocytic sarcoma. Neoplastic cells were negative for cytokeratin, CD79a, and CD3 and positive for CD18, vimentin, lysozyme, and alpha-1-antitrypsin, most consistent with a diagnosis of histiocytic sarcoma. This is the first report of a histiocytic sarcoma involving a joint of a cat. The final diagnosis was based on the light microscopic appearance in combination with the immunohistochemical stains.     

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.     

Synovial sarcoma in the dog–a review

A series of eight cases of synovial sarcoma in the dog is presented together with a literature review of previously reported cases. It is an uncommon tumour occuring mainly around joints and affects more males than females. It occurs most frequently in medium to large dogs of middle age. Clinical signs may develop over a long period of time and the tumour is locally invasive with an unpredictable capacity to metatasise. Radiographically it appears as a soft tissue mass which invades bone. Histological diagnosis may be difficult because of the heterogenicity of the tumour and suitable biopsy techniques are discussed. On present evidence amputation appears to be the most effective form of treatment in the dog.     

Non-neoplastic surgical diseases of the lung and pleura

Non-neoplastic diseases of the bronchi, pulmonary parenchyma, mediastinum, and pleura that are amenable to surgical management represent a wide range of unrelated etiopathogenic conditions that usually have a focal distribution. The author discusses the presurgical clinical, radiographic, and laboratory assessment and prognoses, and addresses therapeutic recommendations.     

Anaplastic sarcoma in the caudal thigh of a horse.

A 16-year-old showjumping gelding was examined because of a non-painful, slowly progressive caudal thigh swelling, which was associated with 2/10th lameness at the trot. Radiography, real time beta-mode ultrasonography and gamma-scintigraphy of the caudal thigh for the presence of chip fractures, sequestrum formation and, or, abscessation were inconclusive. Radiographic examination of the chest revealed multifocal, nodular cannon ball-like opacities throughout the entire lung fields from which a diagnosis of a primary soft tissue tumour with metastasis to the thorax was made. An anaplastic sarcoma was diagnosed port mortem in the candal thigh. At no time did the horse show signs of respiratory embarrassment.     

Renal dysplasia in a pig

A diagnosis of renal dysplasia was made in a six-month-old, male, mixed-breed pig. Both kidneys were small, firm, slightly pitted, and contained an indistinct corticomedullary junction. Histologically, primitive tubules were present surrounded by an abundant loose, mesenchymatous stroma. Occasionally, tubules were markedly dilated and lined by a pseudostratified columnar epithelium forming epithelial mats that obscured the lumina. Immature glomeruli were present. Multifocal glomerular sclerosis was evident. Other mature glomeruli were enlarged and characterized by mesangial cell hyperplasia forming an arborizing pattern.     

An undifferentiated sarcoma in the cervical region in a horse

An Italian Saddle Horse mare was admitted for a hard, nonpainful mass localised in the cervical region. Clinical and diagnostic investigations were performed, which were suggestive of a multilobulated ossifying mass of neoplastic origin. Due to poor prognosis the horse was subjected to euthanasia. Post mortem computed tomography, anatomopathological examination and immunohistochemistry were used to make a definitive diagnosis of undifferentiated sarcoma in the cervical region.     

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.     

Spinal meningeal sarcoma in a rottweiler puppy

An 11-week-old rottweiler puppy was presented for evaluation of progressive paraparesis, urinary and faecal incontinence. Radiography and myelography revealed widening of the vertebral canal and remodelling of several lumbar vertebrae associated with an intramedullary spinal mass. Magnetic resonance imaging revealed an extensive, heterogeneous mass involving the lumbosacral spinal cord. Histopathological examination indicated a meningeal sarcoma with very varied cytological architecture.     

Chromosomal hyperdiploidy in a feline sarcoma.

An eight-year-old male cat developed a sarcoma. The cytogenetic evaluation of the tumour cells showed the presence of hyperdiploidy (range 40 to 46 chromosomes). This hyperdiploidy was encountered in all the cells examined. Extra-chromosomes numbers C1, C2, B4, D4 and E3 were mainly responsible for the hyperdiploid chromosomal complements. There was a high incidence of monosomy E3.     

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.     

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.     

Synovial sarcoma of the tendon and tendon sheath in a dog

A 19.5-year-old male mongrel dog developed a progressive lameness and swelling around the right carpus. A tumor (6 x 3 x 3 cm) was found in the caudal of distal antebrachium of the right forelimb, including tendons of the superficial digital flexor muscle and deep digital flexor muscle. No joint destruction was observed. The tumor consisted of round and spindle cells arranged in a compact sheet. There were occasional slit-like spaces or lumina, and areas rich in collagen fibers giving an appearance of tendon tissues. Neoplastic cells gave a positive immunoreaction to vimentin, but negative reactions to antibodies against S-100 protein, cytokeratin and myoglobin. Based on these findings, this tumor was diagnosed as a synovial sarcoma generating from the tendon and tendon sheath, which is very uncommon in dogs.