Clinicopathological and immunological characteristics of six cats with granular lymphocyte tumors

Clinical and immunological characteristics were investigated in six cases of feline granular lymphocyte (GL) tumor. The ages of the affected cats were relatively old, ranging from 4 to 13 years of age. Gastrointestinal signs were commonly observed in these cases. Only one of the six GL tumor cases was positive for feline leukemia virus (FeLV) antigen. Phenotypic analysis revealed that the GL tumor cells from all of the six cases lacked the T- or B-cell markers. These GL tumor cells were examined by Southern blot analysis using feline immunoglobulin (Ig) and T-cell receptor (TCR) gene probes. GL tumor cells obtained from two cases were identified as cells of T-cell lineage by the presence of a rearranged TCR beta gene, whereas those from the other four cases were considered to be derived from non-T- non-B-cell lineage because of the absence of rearrangement of these genes. These findings indicated that feline GL tumors can be considered as a specific disease entity in feline lymphomas because the cases examined in this study showed onset at an older age, a low incidence of FeLV infection and frequent involvement of gastrointestinal lesions, which are not found in typical FeLV-associated lymphomas. Although no specific phenotypes was observed by phenotypic analysis, the feline GL tumor cells were divided into two consistent genotypes of T-cell or non-T- non-B-cell lineages.

Appearance of canine abdominal tumors with magnetic resonance imaging using a low field permanent magnet

The study was carried out to evaluate the applicability of magnetic resonance imaging (MRI) in detecting tumors in the abdomen of the dog. Abdominal ultrasound and MRI were performed on 8 dogs having a mass lesion on abdominal radiography. MR images were obtained in the transverse, sagittal and dorsal planes using T1- and T2-weighted spin echo pulse sequences. There was good visual correlation of the lesion site by MRI and ultrasonography (US).

Imaging abdominal masses

Both radiography and ultrasound provide noninvasive imaging of suspected abdominal masses with minimal discomfort or risk for the geriatric patient. Radiography is more readily available and less expensive than ultrasonography, but contrast resolution is poor. Displacement of adjacent structures and addition of special contrast studies will provide clues to the possible organ of origin and extent of suspected abdominal masses. Cystic lesions can be differentiated from solid masses with ultrasound, but the appearance of focal abnormalities is not specific for any one disease process. Abdominal ultrasonography often provides the best diagnostic yield when used in combination with radiography and image-guided biopsy techniques.

Peripheral neuroblastoma in a dog

Primitive neuroectodermal tumors are composed of primitive neuroepithelial cells and include tumors of the central and peripheral nervous system. Neuroblastoma, medulloblastoma and retinoblastoma are examples of these rare malignant tumors that usually occur in young patients. This report describes a peripheral neuroblastoma in a 2 year old Boxer that presented with signs of renal disease and a palpable abdominal mass. The purpose of this paper is to describe the clinical presentation, imaging and immunohistological studies of this abdominal tumor in a young dog and to review the literature.

Establishment and characterization of spontaneous mesothelioma cell lines derived from F344 rats

Three mesothelioma cell lines (MeET-4, MeET-5, and MeET-6) established from ascitic fluid of F344 rats with spontaneous abdominal mesothelioma have been maintained through at least 60 passages on the DMEM with 10% FBS. Two of original tumours consisted of epithelioid cells growing in a papillary pattern, while one (original tumour of MeET-5) had sarcomatous areas composed of spindle-shaped tumour cells. The cell line originating from MeET-5 showed a constantly beiphasic growth pattern during the repetitive subcloning, while the other two lines retained a monophasic growth pattern. Although the growth pattern was different, the tumour cells in all three lines were positive for vimentin and keratin and ultrastructurally showed an abundant distribution of glycogen granules in the cytoplasm and numerous long microvilli on all surface. The modal chromosome number of cell lines varied from 41 to 71, and abnormal chromosomes were frequently seen. All cell lines established formed colonies on semi-solid medium and could be successfully transplanted, growing tumour masses in syngeneic rats and thus indicating their malignant nature. Cell lines grew even on a medium with a low concentration of FBS. The evidence suggests that they may produce growth factors that enable them to survive unfavourable medium conditions.

Hypertrophic osteoarthropathy in a blesbok (Damaliscus dorcas phillipsi)

A 4.5-yr-old female blesbok (Damaliscus dorcas phillipsi) was radiographed following the appearance of lameness and swelling of the right front fetlock. Radiographic interpretation at that time was osteoarthritis caused by periosteal proliferation of the right metacarpus with periarticular osteophytes surrounding the fetlock. No treatment was initiated. Gradual abdominal enlargement over several months was interpreted as evidence of pregnancy. Six months after the initial lameness complaint, the blesbok suddenly collapsed and was unable to stand. Physical examination revealed a large firm mass occupying most of the abdomen that was found to be inoperable. Following exploratory laporotomy, the blesbok was euthanized. At necropsy, the mass weighed 17 kg. It had probably caused the animal's collapse. Histologically, the bony lesions of the right metacarpus, seen radiographically at the previous examination, were consistent with hypertrophic osteoarthropathy and may have been a sequela of the intra-abdominal mass.

Gastric squamous cell carcinoma in three horses

Gastric squamous cell carcinoma was diagnosed in three horses. Clinical signs observed in all cases were weight loss, anorexia and lethargy. Respiratory signs were prominent in one case. All three horses had depressed albumin and elevated globulin and fibrinogen concentrations. Two horses were mildly anaemic. Inflammatory exudates were present in peritoneal cavities in all cases, and cytological evaluation provided a positive diagnosis of squamous cell carcinoma in two cases. Pleural fluid samples taken from two cases were also classified as inflammatory exudates, but no neoplastic cells were detected on initial examination. In all cases the neoplasms had arisen from the oesophageal region of the stomach, and had metastised throughout the abdomen. Two cases had metastatic lesions within the pleural cavity.

Intraabdominal lymphangiosarcoma in a Fischer-344 rat

A Sarcoma arising in the abdominal cavity in an aged Fischer-344 rat was studied by immunohistochemistry and electron microscopy. The white-yellow soft mass was located on the lumbosacral vertebrae, compressing adjacent parenchymal organs. The tumor was made up of spindle shaped cells situated in a background of myxoid substance and a small amount of reticulin and collagen fibers. The tumor cells grew in a loose storiform pattern and often adhered to each other by their cell processes to form ovoid or slitlike spaces. Immunohistochemically, the tumor cells were strongly positive for vimentin but negative for keratin, macrophage ED1 antigen, alpha-smooth muscle actin, Factor VIII-related antigen, and S100 protein. Electron microscopy demonstrated the endothelial differentiation of the tumor cells, such as occasional luminal spaces, a small number of micropinocytotic vesicles, and interdigitating junctions with desmosomes between cell processes of adjacent cells. Furthermore, its endothelial origin was suggested by the presence of electron-dense rods resembling Weibel-Palade bodies. Instead of a definitive basement lamina surrounding the tumor cells, there were extracellular thin "anchoring filaments" that were attached to the cell surface at areas of increased electron density. These findings indicate that the tumor is of lymphatic vessel type rather than blood vessel type.

Triphasic nephroblastoma in a horse

A large abdominal mass in a 3-year-old filly was discovered clinically and removed and examined after the horse had been humanely killed. Histologically, three different tissue types were noted, occurring in equal amounts: epithelium largely in the form of well-differentiated tubules, multifocally distributed cell-dense foci of blastema, and myxoid to fibrous stroma. A diagnosis of triphasic nephroblastoma, a rare tumour in the horse, was made on the basis of microscopical findings. The finding of numerous glomeruloid structures confirmed the diagnosis and assisted in distinguishing the tumour from a teratoma. The histogenesis of nephroblastoma is briefly discussed in the context of the histological and immunohistochemical findings of the case.

Hypoglycemia associated with intra-abdominal leiomyoma and leiomyosarcoma in six dogs

Intra-abdominal leiomyoma or leiomyosarcoma was diagnosed in 6 dogs that had hypoglycemia (resting blood glucose concentration < 50 mg/dl). Tumors were large (12 to 24 cm) and arose from intra-abdominal structures including the jejunum, pylorus, duodenum, stomach, and liver. Four dogs had a leiomyoma, and 2 dogs had a leiomyosarcoma. In those dogs in which the tumor was successfully removed at surgery, blood glucose concentration returned to the reference range after tumor resection. Four dogs lived for at least 12 months after tumor resection, without redeveloping hypoglycemia.

Use of imipramine hydrochloride for treatment of urospermia in a stallion with a dysfunctional bladder

An 8-year-old stallion was evaluated because of recurrent urinary tract infections and chronic intermittent urospermia. After extensive diagnostic testing, it was hypothesized that the stallion had a reflex dyssynergia of the bladder and urethral sphincter. Initial attempts to manage the urospermia included semen fractionation, semen collection after voluntary urination, and use of semen extenders. None of these efforts reliably yielded a quality ejaculate. Administration of imipramine hydrochloride (1.2 mg/kg of body weight, PO, 4 hours prior to semen collection) was initiated in an attempt to enhance bladder neck closure during ejaculation. This treatment, combined with voluntary urination prior to ejaculation, resulted in ejaculates containing little or no urine. Using this protocol, 19 of 20 mares bred during the subsequent 2 years became pregnant. By the third year, the bladder dysfunction had progressed, and the urospermia was no longer manageable. Bladder catheterization, followed by manual expression of the bladder per rectum, were necessary prior to each semen collection to obtain a urine-free ejaculate. Three-and-a-half years after initial examination, transitional cell carcinoma of the bladder with metastasis was identified, and the stallion was euthanatized. It is not known whether the transitional cell carcinoma was related to the dysfunctional bladder. Imipramine hydrochloride did not eliminate, but did reduce, the frequency and degree of urospermia in the affected stallion for approximately 2 years.

Radiation therapy of thoracic and abdominal tumors

Until recently, radiotherapy of thoracic and abdominal tumors in animals has been limited. However, the availability of computerized tomography and other imaging techniques to aid in determining the extent of tumor, an increase in knowledge of dose tolerance of regional organs, the availability of isocentrically mounted megavoltage machines, and the willingness of patients to pursue more aggressive treatment is making radiation therapy of tumors in these regions far more common. Tumor remission has been reported after radiation therapy of thymomas. Radiation therapy has been used to treat mediastinal lymphoma refractory to chemotherapy, and may be beneficial as part of the initial treatment regimen for this disease. Chemodectomas are responsive to radiation therapy in human patients, and favorable response has also been reported in dogs. Although primary lung tumors in dogs are rare, in some cases radiation therapy could be a useful primary or adjunctive therapy. Lung is the dose-limiting organ in the thorax. Bladder and urethral tumors in dogs have been treated using intraoperative and external-beam radiation therapy combined with chemotherapy. These tumors are difficult to control locally with surgery alone, although the optimal method of combining treatment modalities has not been established. Local control of malignant perianal tumors is also difficult to achieve with surgery alone, and radiation therapy should be used. Intraoperative radiation therapy combined with external-beam radiation therapy has been used for the management of metastatic carcinoma to the sublumbar lymph nodes. Tolerance of retroperitoneal tissues may be decreased by disease or surgical manipulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Diffuse abdominal epithelioid mesothelioma in a cow

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Malignant mesothelioma with metastases and mast cell leukaemia in a cat

Abdominal malignant mesothelioma was found in a 17-year-old, spayed female Japanese domestic cat with mast cell leukaemia. The mesothelioma was mainly located at the periphery of the pancreas, spleen and stomach, and showed metastases to the lung, an anterior mediastinal lymph node and lymph ducts in the tracheal mucosa. Micro-circulatory defects caused by the mast cell leukaemia may have been partly responsible for the distant metastases.

Canine splenic hemangiosarcoma with abdominal dissemination

Disseminated hemangiosarcoma was encountered in a 12-year-old female Maltese dog. Tumor tissues were dispersed on the serosal surface of the liver, kidney, digestive tract, omentum and diaphragm. Metastatic lesions were not observed in the parenchyma of the lung and heart. The spleen was enlarged with rupture at the anterior region of the hilus. The disseminated protruding tumor masses could be easily peeled off from the organ surfaces. The tumor cells were round or spindle in shape, with hyperchromatic nuclei containing prominent nucleoli. Various-sized vascular spaces containing erythrocytes and serum could be identified in this tumor. This case was diagnosed as hemangiosarcoma originating from the spleen with abdominal dissemination.

Visceral mast cell tumour with eosinophilia and eosinophilic peritoneal and pleural effusions in a cat

A cat with weight loss, pyrexia and recurrent lethargy and depression was found to have pleural and peritoneal eosinophilic effusions, peripheral eosinophilia, eosinophilic lymphadenitis and a massively enlarged mesenteric lymph node. Visceral mast cell neoplasia was diagnosed after histopathological examination of a biopsy of the mass. Palliative chemotherapy was attempted unsuccessfully and the cat was euthanased.

[Feline ocular melanoma. Clinical and pathologico-anatomic findings in 37 cases]

The clinical and pathological findings of 37 feline ocular melanomas are described. The majority of the tumors examined were diffuse iris-ciliary body melanomas of epithelioid and pleomorphic (anaplastic) cell type with numerous mitotic figures. The majority of the tumors showed invasion of the anterior sclera. Metastases were found in three cases predominantly in the abdominal viscera (liver). The clinical diagnostics as well as the differential diagnosis, therapy and prognosis of feline uveal melanoma are presented. The causal pathogenesis is discussed comparatively.

Granulated round cell tumor of cats

Morphologic and biologic features of five feline granulated round cell tumours were compared with those previously reported to be of globule leukocyte and large granular lymphocyte origin. The five cats ranged from 6 to 9 years of age and presented with nonspecific gastrointestinal signs. Four of the five cats were tested for feline leukemia virus and were negative by enzyme-linked immunosorbent assay. The neoplastic process involved the abdominal cavity in all cases, with a predilection for the distal small intestine and mesentery. The liver and peripheral and thoracic lymphoid tissues were also sporadically affected. Neoplastic round cells contained 0.5-1.5-microns eosinophilic cytoplasmic granules that were difficult to discern on causal observation with hematoxylin and eosin stain but were deep blue and easily visualized when stained with phosphotungstic acid-hematoxylin. In two cases, epithelium in the affected ileum and liver contained unusually large numbers of apparently normal globule leukocytes. Ultrastructurally, the tumor granules tended to cluster at one nuclear pole and were spindle to round in shape with variably dense contents. Some granules contained a dense "cap" at one end or internal crystalloid bars that distorted the granule membrane. The tumors reported herein are similar to all three of the previously reported feline granulated round cell tumors and probably have a common cellular origin.

Intestinal strangulation caused by intra-abdominal lipomas in a dog

Pedunculated, intra-abdominal lipomas caused intestinal strangulation in a Doberman Pinscher. The dog was treated surgically to remove the lipomas and the devitalized intestine but died soon after surgery. Histologic evaluation confirmed the diagnosis of lipoma.