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Case Description: A 19-year-old neutered male domestic shorthair cat was evaluated because of signs of urinary tract obstruction., Clinical Findings: Physical examination findings were consistent with urethral obstruction, and a mass could be palpated in the region of the bladder neck. Abdominal ultrasonography and thoracic radiography revealed a mass in the trigone of the urinary bladder and a solitary mass in the left caudal lung lobe. Cytologic examination of the urine sediment, samples obtained by means of traumatic urethral catheterization, and fine-needle aspirates of the bladder mass did not result in a diagnosis., Treatment and Outcome: A balloon-expandable metallic stent was placed in the proximal portion of the urethra to relieve the malignant obstruction. After stent placement, the cat had signs of urinary incontinence and detrusor atony, both of which resolved with medical treatment. The cat was euthanized 1 month after stent placement because of progressive azotemia. Histologic examination of necropsy samples revealed grade III urothelial carcinoma and papillary pulmonary adenocarcinoma., Clinical Relevance: Findings suggested that stent placement may be a viable palliative treatment in cats with malignant urinary obstruction.

Nine dogs and 9 cats with ceruminous gland carcinoma were evaluated to determine whether they would receive radiation therapy. Tissue samples were reviewed to confirm the diagnosis and to assess completeness of resection in animals that had undergone surgery. Seven animals were excluded because surgical excision was determined histologically to have been complete (5) or because the owners did not wish to pursue treatment, because of advanced disease (2). The remaining 6 cats and 5 dogs, 6 of which had previously undergone surgery, were included in the study. The radiation therapy dose was 48 Gy, given in 12 fractions over 4 weeks. The product-limit estimate of mean progression-free survival time was 39.5 months. The estimate of 1-year progression-free survival rate was 56%. The tumor recurred in 4 animals, and metastases were observed in 3 animals. Radiation therapy was found to be safe and effective.

Renal adenoma, a benign tumor of epithelial origin, was diagnosed in a 10-year-old cat. Clinical signs included decreased appetite and weight loss. Nephrectomy resulted in clinical improvement. Seven months after surgery, the cat died, and pulmonary papillary adenocarcinoma was discovered. The pulmonary neoplasm differed markedly from the renal neoplasm.

An 11-year-old Quarter Horse mare was presented with ventral edema and pleural effusion, secondary to a disseminated ovarian adenocarcinoma. Bilateral thoracocentesis yielded 30 L of thin, blood-tinged fluid, which was a modified transudate. Cytologic examination of the fluid revealed large atypical cells, suggestive of carcinomatous neoplasia. Similar cells were found in the peritoneal fluid. The mare was euthanatized. Necropsy revealed a 35-cm diameter mass in the cranial mediastinum, ventral to the trachea. The left ovary was 25 cm in diameter and most of the parenchyma was replaced by red or brown friable tissue, containing numerous 1-to 3-mm cysts. Papillary adenocarcinoma of the ovary was diagnosed, based on the appearance and arrangement of tumor cells in the ovary, sublumbar and tracheobronchial lymph nodes, and mediastinal mass. Ovarian neoplasia should be considered in the differential diagnosis of pleural effusion in the horse.