Urothelial carcinoma with tonsillar metastasis in a dog.

Given its unusual lymphatic drainage system, the tonsil is a rare site of metastasis, with few reports in the human and veterinary literature. Prognosis in cases of tonsillar metastasis is reportedly poor. We describe here a unique case of urinary bladder urothelial carcinoma (UC) with metastasis to the tonsil in an 11-y-old, spayed female, mixed-breed dog. At presentation, the patient had a history of a growing neck mass and increasing lethargy, hyporexia, weight loss, drooling, and diarrhea for 2 wk. A carcinoma was diagnosed by cytology. Given the poor prognosis, the patient was euthanized. Postmortem examination revealed masses in the inguinal region, cranioventral neck region including tonsil, and urinary bladder. Histologically, the masses were composed of large polyhedral cells arranged in dense sheets and nests with occasional large, clear, intracytoplasmic vacuoles. Neoplastic cells were multifocally positive for uroplakin III and cytokeratin 8/18 by immunohistochemistry. UC with metastasis to tonsil and lymph nodes was diagnosed.

COMPARISON BETWEEN THORACIC RADIOGRAPHIC FINDINGS AND POSTMORTEM DIAGNOSIS OF THORACIC DISEASES IN DYSPNEIC COMPANION RATS (RATTUS NORVEGICUS).

Companion rats are often presented to veterinarians for respiratory difficulties. Dyspnea in rats is most commonly due to infectious pneumonia, and thoracic neoplasia can go undiagnosed ante mortem due to a mistaken interpretation of pneumonia. In domestic carnivores, pulmonary nodular patterns have been shown to correlate with lung neoplastic diseases and infectious diseases. The main objective of this retrospective case series study was to determine whether certain radiographic criteria could be correlated with the presence of thoracic infectious disease and neoplastic disease in companion rats. A secondary objective was to determine whether the patient's sex and age were different between rats diagnosed with infectious versus neoplastic disease. Medical records and thoracic radiographs of dyspneic companion rats presented to the University of California at Davis, William R. Pritchard Veterinary Medical Teaching Hospital during the time period from January 2000 to December 2014 were reviewed. Rats with postmortem confirmation of thoracic lesions were included in the study. Thoracic radiographs were evaluated for positioning, lesion distribution, lung lobe involved, pulmonary pattern, mediastinal and pleural lesions by three observers blinded to diagnosis. Thirty rats were included in the study, including 23 rats with an infectious disease and seven with neoplasia. Mediastinal lesions were significantly more prevalent in the group diagnosed with thoracic neoplasia (P = 0.031), in particular cranially (P = 0.048). Although there was an overlap between the two groups, findings indicated that the presence of cranial mediastinal lesions may be helpful for differentiating neoplastic from infectious disease in rats.

Feline Respiratory Extramedullary Plasmacytoma with Lymph Node Metastasis and Intrahistiocytic Amyloid.

A 14-year-old domestic longhaired cat presented with a 2-year history of nasal discharge and a recent onset of inappetence and submandibular lymphadenopathy. The cat was humanely destroyed after developing severe respiratory distress. Necropsy examination revealed thickened nasal turbinates and soft palate, and friable red-tan material within the frontal sinus, nasal cavity and nasopharynx. The lungs contained multifocal irregular friable tan nodules. Multiple lymph nodes were enlarged, friable and red-tan in colour. Histopathology revealed a mature type extramedullary plasmacytoma (EMP) within the frontal sinus, nasal cavity, soft palate, larynx, trachea, lungs and multiple lymph nodes. The lymph nodes and larynx also contained marked granulomatous inflammation with extensive intrahistiocytic (and lesser amounts of extracellular) lambda light chain amyloid, confirmed by electron microscopy and immunohistochemistry. Neoplastic cells expressed CD79a and MUM1. This is the first report of an infiltrative EMP of the feline respiratory tract with lymph node metastasis and predominantly intrahistiocytic amyloid.

Hernia of the swim bladder (aerocystocele) with concurrent mycotic granulomatous inflammation and swim bladder carcinoma in a wild mullet (Mugil cephalus).

We describe a hernia of the swim bladder, with a concurrent mycotic granulomatous inflammation, and carcinoma of the swim bladder in a wild mullet (Mugil cephalus) referred for an exophytic dorsal mass. Grossly, the mass was white, soft, and composed of multiple cystic gas-containing chambers connected by a funnel-shaped tissue segment to the coelomic swim bladder. Histologically, the mass was characterized by cysts of variable size, multifocally contiguous with the subepithelial rete mirabile, supported by abundant fibrous tissue. The skin covering the herniated swim bladder was focally ulcerated and replaced by abundant granulation tissue in which multiple scattered granulomas centered on pigmented fungal hyphae were observed. These granulomas were also seen in the remaining coelomic portion of the swim bladder as well as in the spleen, perivisceral pancreas, and peritoneal adipose tissue; the fungus was molecularly identified as Cladosporium spp. Focally, arising from the herniated swim bladder epithelium, an unencapsulated poorly demarcated, moderately cellular neoplasm, composed of islands, lobules, and acini of neoplastic epithelium, was found.

Air sac adenocarcinoma of the sternum in a Quaker parrot (Myiopsitta monachus).

Respiratory neoplasia is rarely reported in avian species. A 17-yr-old Quaker parrot (Myiopsitta monachus) was admitted with a 2-wk history of anorexia, depression, and respiratory distress. Clinical examination revealed a large, firm mass in the left pectoral muscle. Radiology showed a mass silhouetting the heart and the liver. Supportive treatment was provided, but the bird died during the seventh weekly visit to drain thoracic cavity fluid. Necropsy showed a white, 3 x 3 x 2-cm, hard, gritty sternal mass. Histology showed a nonencapsulated, moderately differentiated air sac carcinoma of the sternum. Immunohistochemically the neoplasm was cytokeratin positive and vimentin and calretinin negative. This is the first report of an air sac neoplasia in a Quaker parrot and one of few respiratory tumors in psittacines.

A complicated, metastatic, humeral air sac cystadenocarcinoma in a timneh African grey parrot (Psittacus erithacus timneh).

A 9-year-old male timneh African grey parrot (Psittacus erithacus timneh) was presented because of inability to fly and suspected trauma. The owner also had observed dyspnea, with tail bobbing and open-beak breathing. On clinical examination, a hard, painful mass was palpable in the left proximal humerus and axillary area. Radiographs revealed a radiodense soft tissue mass of the left humerus with no bony involvement, multifocal opacities in lung and air sacs, and an enlarged spleen. An asymmetric, vascularized cyst was detected in the mass by ultrasound examination. Results of biopsy of the mass revealed multifocal cysts composed of unilayer isoprismatic cells laying in vascularized connective tissue. Because of the severity of clinical signs and the poor clinical condition, the bird was euthanatized. On postmortem examination, the findings were air sac cystadenocarcinoma involving the humeral air sac with metastases in the spleen and kidneys, atherosclerosis, pneumoconiosis, and mycotic granulomatous pneumonia and airsacculitis with isolation of Aspergillus niger.

Swimbladder Leiomyosarcoma in Atlantic salmon (Salmo salar) in North America.

Leiomyosarcoma with associated retrovirus were found in North America for the first time in adult Atlantic salmon (Salmo salar) held in a quarantine facility at the North Attleboro National Fish Hatchery (NANFH), Massachusetts, USA. The fish had been collected as age 1-2 yr animals from the Pleasant River, Maine, and were to be used as brood stock in a population augmentation program for that river. Neoplastic disease was observed at NANFH initially in older (age 4 yr) fish, followed by age 3 yr fish. Disease was not observed in age 2 yr fish. The mortality pattern was chronic.

Proliferative and nonproliferative lesions of the rat and mouse respiratory tract.

The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally-accepted nomenclature for proliferative and non-proliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the respiratory tract of laboratory rats and mice, with color photomicrographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous developmental and aging lesions as well as lesions induced by exposure to test materials. A widely accepted and utilized international harmonization of nomenclature for respiratory tract lesions in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.

Airsac cystadenocarcinomas in cockatoos.

The clinical signs, radiographic and pathological findings of four histologically similar neoplasms that occurred as unilateral tumours projecting from the left axilla in three galahs (Eolophus roseicapillus) and one sulphur-crested cockatoo (Cacatua galerita) are described. In each case, the main reason for clinical presentation was respiratory distress. All cases were eventually fatal due to airway obstruction with evidence of extensive neoplastic invasion of the lungs, major airways and or humerus in all cases. A diagnosis of airsac cystadenocarcinoma was made in each bird on the basis of gross and histological appearance. The neoplasms were composed of fluid or air-filled sacs of proliferative cuboidal to squamous epithelial cells that stained positively with cytokeratin and negatively with vimentin. This was supported by a thin fibrovascular network although at least some areas in all four birds resembled airsac tissue. In some cases areas of haemorrhage, erythrophagocytosis, haemosiderosis and nodules of haemosiderophage infiltration with acicular cholesterol clefts were present in some parts of the sectioned tissue.

Respiratory medicine of cage and aviary birds.

Respiratory diseases are a relatively common cause of illness and death in cage birds. A diagnostic algorithm is provided based on history, physical examination, and ancillary diagnostic findings that assist clinicians in determining the cause of a bird's respiratory disease. Also included are detailed descriptions of the common respiratory diseases of cage birds and their treatment.

Respiratory diseases, diagnostics, and treatment of marsupials.

Primary respiratory disease is uncommon in marsupials, but generalized disease often involves the respiratory tract in these animals. Other disease entities may spread to involve the respiratory system secondarily. Treatment is challenging because most animals are severely compromised on presentation. Bacteria, viruses, parasites, fungi and yeasts, trauma, and neoplasia all can affect the respiratory systems of marsupials. Some of these conditions are only incidental findings, whereas others are pathogenic. Many therapies and diagnostic procedures are extrapolated from those in companion animal medicine and surgery. Despite the problems associated with the diagnosis and treatment of respiratory disease in marsupials, new therapeutic agents and diagnostic techniques are making these tasks easier and ultimately more successful.

Proliferative lesions in swimbladder of Japanese medaka Oryzias latipes and guppy Poecilia reticulata.

Thirteen cases of proliferative lesions of the swimbladder were encountered in Japanese medaka Oryzias latipes and guppy Poecilia reticulata from about 10,000 medaka and 5000 guppies used in carcinogenicity tests and histologically examined. Two of the 4 cases from medaka and 8 of the 9 from guppies occurred in untreated control specimens. The lesions affected the gas gland epithelium and included hyperplasia, adenoma, and adenocarcinoma. One medaka had hyperplasia of the gas gland epithelium and in 1 guppy the gland was enlarged with an increase in the number of epithelial layers. Gas gland adenomas, 3 cases in medaka and 1 in the guppy, were typically larger than the hyperplastic lesions, formed expansive masses up to 1 mm in greatest dimension, and exhibited a solid or glandular growth pattern and mild cellular pleomorphism. Adenocarcinoma was the most advanced lesion and all 7 cases occurred in guppies. Adenocarcinomas sometimes filled the entire swimbladder and measured up to 2.5 mm in diameter. Cells of adenocarcinomas were highly pleomorphic, with atypical nuclei, and an elevated mitotic activity. Because most of these tumors occurred in fish from control groups or in tests with noncarcinogenic compounds, the lesions observed here are probably spontaneous rather than chemically induced. Their rare occurrence, however, makes swimbladder proliferative lesions in small-fish carcinogenesis models sensitive indicators of compounds that might target cells of the gas gland.

Spontaneous tumours in tree shrews (Tupaia belangeri): population studies.

In a necropsy series at the German Primate Centre, 63 of 1132 tree shrews were found to have tumours. The youngest affected animal was < 6 months old, but the incidence of tumours increased strikingly beyond 2 years of age; of 17 animals aged > 8 years, no less than 14 (82.4%) were affected. The sites of neoplasia were the genital system (22 cases), haematopoietic system (18 cases of malignant lymphoma, many involving the digestive tract), lungs (14 cases), integument (five cases), digestive tract (three cases other than those with malignant lymphoma) and urinary bladder (one case).

Neoplasia of the respiratory tract.

Tumors of the equine respiratory tract occur infrequently. An accurate diagnosis of neoplasia of the respiratory tract is critical because the prognosis is usually grave. The clinical signs and diagnostic procedures are discussed for tumors of the nasal and paranasal sinuses, nasopharynx/larynx, guttural pouch and thorax including lung, pleura, and thymus.

Surgery of the respiratory system.

Diseases affecting the respiratory tract are common in cattle; however, surgery required for treatment of these diseases is infrequent. Therefore, veterinarians may be reluctant to perform these surgical procedures. Familiarity with the variety and complexity involved in various surgical procedures should reduce this anxiety. When used, surgery of the respiratory tract can offer significant benefit to the patient and profitable returns to the owner.

Spontaneous neoplasms in aged Sprague-Dawley rats.

Incidence of neoplastic lesions in untreated Sprague-Dawley rats (1340 males and 1329 females) used as controls in 17 carcinogenicity studies are tabulated and evaluated. In male rats, the most common neoplasms were benign pheochromocytomas and keratoacanthomas (4.0% in each case) followed by pancreatic islet cell adenomas (3.7%), thyroid parafollicular cell adenomas (3.6%), fibromas and squamous cell papillomas of the skin and hepatocellular adenomas (2.0% in each), malignant lymphoma lymphocytic (1.9%), histiocytic sarcomas (1.4%), and adrenal cortical adenomas (1.2%). In female rats, the most common neoplasms were of mammary gland origin (31.3%: fibroadenoma 19.0%, adenocarcinomas 8.8%, and adenomas 3.5%) followed by thyroid parafollicular cell adenomas (2.9%), uterine endometrial stromal polyps (2.6%), adrenal cortical adenomas (1.9%), malignant lymphoma lymphocytic (1.6%), fibromas in the skin (1.3%), and pancreatic islet cell adenoma (1.1%). Metastases were observed from pheochromocytomas, hepatocellular carcinomas, nephroblastomas, renal pelvis transitional cell carcinoma, interstitial cell tumor and seminoma of the testes, Zymbal's gland adenocarcinomas, and mammary adenocarcinomas.

Spontaneous tumors in F-344/Jcl rats.

The age-related incidence of spontaneously occurring neoplastic and non-neoplastic lesions in untreated F-344/Jcl rats, used as controls in carcinogenicity testing, were studied from the histological examination of tissues from 469 males and 354 females. The incidence of spontaneous tumors was 83.2% in the males and 71.2% in the females. The most common neoplasms were leukemia (males: 24.3%, females: 24.0%), pituitary adenoma (males: 16.0%, females: 45.2%), pheochromocytoma (males: 14.7%, females: 7.3%), testicular interstitial cell tumor (males: 79.1%), and uterine endometrial stromal polyp(females: 16.4%). The incidence of other tumors of almost all the organs and/or tissues was low. Non-neoplastic lesions generally increased with advancing age of the animals.