Methods in isolation and characterization of bovine monocytes and macrophages.

Monocytes and macrophages belong to the mononuclear phagocyte system and play important roles in both physiological and pathological processes. The cells belonging to the monocyte/macrophage system are structurally and functionally heterogeneous. Several subsets of monocytes have been previously identified in mammalian blood, generating different subpopulations of macrophages in tissues. Although their distribution and phenotype are similar to their human counterpart, bovine monocytes and macrophages feature differences in both functions and purification procedures. The specific roles that monocytes and macrophages fulfil in several important diseases of bovine species, including among the others tuberculosis and paratuberculosis, brucellosis or the disease related to peripartum, remain still partially elusive. The purpose of this review is to discuss the current knowledge of bovine monocytes and macrophages. We will describe methods for their purification and characterization of their major functions, including chemotaxis, phagocytosis and killing, oxidative burst, apoptosis and necrosis. An overview of the flow cytometry and morphological procedures, including cytology, histology and immunohistochemistry, that are currently utilized to describe monocyte and macrophage main populations and functions is presented as well.

Tyrosine Kinase Receptor Expression in Canine Liposarcoma.

The expression of tyrosine kinase receptors is attracting major interest in human and veterinary oncological pathology because of their role as targets for adjuvant therapies. Little is known about tyrosine kinase receptor (TKR) expression in canine liposarcoma (LP), a soft tissue sarcoma. The aim of this study was to evaluate the immunohistochemical expression of the TKRs fibroblast growth factor receptor 1 (FGFR1) and platelet-derived growth factor receptor-ß (PDGFRß); their ligands, fibroblast growth factor 2 (FGF2) and platelet-derived growth factor B (PDGFB); and c-kit in canine LP. Immunohistochemical labeling was categorized as high or low expression and compared with the mitotic count and MIB-1-based proliferation index. Fifty canine LPs were examined, classified, and graded. Fourteen cases were classified as well differentiated, 7 as myxoid, 25 as pleomorphic, and 4 as dedifferentiated. Seventeen cases were grade 1, 26 were grade 2, and 7 were grade 3. A high expression of FGF2, FGFR1, PDGFB, and PDGFRß was identified in 62% (31/50), 68% (34/50), 81.6% (40/49), and 70.8% (34/48) of the cases, respectively. c-kit was expressed in 12.5% (6/48) of the cases. Mitotic count negatively correlated with FGF2 ( R = -0.41; P < .01), being lower in cases with high FGF2 expression, and positively correlated with PDGFRß ( R = 0.33; P < .01), being higher in cases with high PDGFRß expression. No other statistically significant correlations were identified. These results suggest that the PDGFRß-mediated pathway may have a role in the progression of canine LP and may thus represent a promising target for adjuvant cancer therapies.

Histological Classification and Immunohistochemical Evaluation of MDM2 and CDK4 Expression in Canine Liposarcoma.

Canine liposarcoma is an uncommon soft tissue sarcoma usually arising in the subcutis. While liposarcoma classification in dogs is based solely on histology, in humans it depends on the detection of genetic abnormalities that can lead to specific protein overexpression. This study is an immunohistochemical evaluation of MDM2 and CDK4 expression in canine liposarcoma designed to assess the correlation of these proteins with histologic type, grade, mitotic index and Ki67 labeling index and evaluate their utility in improving tumor classification. Fifty-three liposarcomas were retrospectively collected: 24 were well differentiated liposarcomas (WDL), 16 of which expressed MDM2 and 21 CDK4; 7 were myxoid liposarcomas (ML), 1 of which expressed MDM2 and 5 expressed CDK4; 18 were pleomorphic liposarcomas (PL), all were MDM2 negative and 12 expressed CDK4. Four tumors were morphologically consistent with dedifferentiated liposarcoma (DDL) a subtype described only in humans: 3 expressed MDM2 and 4 expressed CDK4. MDM2 expression correlated with histotype (highly expressed in WDL and DDL) and grade (highly expressed in grade 1 tumors). Histotype correlated with the Ki67 labeling index (lowest in WDL and highest in DDL). A revised classification, considering MDM2 expression, allowed 8 WDL to be reclassified as PL and correlated significantly with mitotic and Ki67 labeling index (both significantly lower in WDL and progressively higher in ML and DDL). These results partially parallel data reported for human liposarcomas, suggesting that WDL and DDL are distinct neoplastic entities characterized by MDM2 expression, which may represent a useful diagnostic and potentially prognostic marker for canine liposarcoma.

Cutaneous Lymphoma at Injection Sites: Pathological, Immunophenotypical, and Molecular Characterization in 17 Cats.

Feline primary cutaneous lymphomas (FPCLs) account for 0.2% to 3% of all lymphomas in cats and are more frequently dermal nonepitheliotropic small T-cell tumors. Emergence of FPCL seems unrelated to feline leukemia virus (FeLV) serological positivity or to skin inflammation. A total of 17 cutaneous lymphomas with a history of vaccine injection at the site of tumor development were selected from 47 FPCLs. Clinical presentation, histology, immunophenotype, FeLV p27 and gp70 expression, and clonality were assessed. A majority of male (12/17), domestic short-haired (13/17) cats with a mean age of 11.3 years was reported. Postinjection time of development ranged from 15 days to approximately 9 years in 5 cats. At diagnosis, 11 of 17 cats had no evidence of internal disease. Lymphomas developed in interscapular (8/17), thoracic (8/17), and flank (1/17) cutaneous regions; lacked epitheliotropism; and were characterized by necrosis (16/17), angiocentricity (13/17), angioinvasion (9/17), angiodestruction (8/17), and peripheral inflammation composed of lymphoid aggregates (14/17). FeLV gp70 and/or p27 proteins were expressed in 10 of 17 tumors. By means of World Health Organization classification, immunophenotype, and clonality, the lesions were categorized as large B-cell lymphoma (11/17), anaplastic large T-cell lymphoma (3/17), natural killer cell-like (1/17) lymphoma, or peripheral T-cell lymphoma (1/17). Lineage remained uncertain in 1 case. Cutaneous lymphomas at injection sites (CLIS) shared some clinical and pathological features with feline injection site sarcomas and with lymphomas developing in the setting of subacute to chronic inflammation reported in human beings. Persistent inflammation induced by the injection and by reactivation of FeLV expression may have contributed to emergence of CLIS.

Growth Factors and COX2 Expression in Canine Perivascular Wall Tumors.

Canine perivascular wall tumors (PWTs) are a group of subcutaneous soft tissue sarcomas developing from vascular mural cells. Mural cells are involved in angiogenesis through a complex crosstalk with endothelial cells mediated by several growth factors and their receptors. The evaluation of their expression may have relevance since they may represent a therapeutic target in the control of canine PWTs. The expression of vascular endothelial growth factor (VEGF) and receptors VEGFR-I/II, basic fibroblast growth factor (bFGF) and receptor Flg, platelet-derived growth factor B (PDGFB) and receptor PDGFRß, transforming growth factor ß1 (TGFß1) and receptors TGFßR-I/II, and cyclooxygenase 2 (COX2) was evaluated on frozen sections of 40 PWTs by immunohistochemistry and semiquantitatively scored to identify their potential role in PWT development. Statistical analysis was performed to analyze possible correlations between Ki67 labeling index and the expression of each molecule. Proteins of the VEGF-, PDGFB-, and bFGF-mediated pathways were highly expressed in 27 (67.5%), 30 (75%), and 19 (47.5%) of 40 PWTs, respectively. Proteins of the TGFß1- and COX2-mediated pathways were highly expressed in 4 (10%) and 14 (35%) of 40 cases. Statistical analysis identified an association between VEGF and VEGFR-I/II (P = .015 and .003, respectively), bFGF and Flg (P = .038), bFGF and PDGFRß (P = .003), and between TGFß1 and COX2 (P = .006). These findings were consistent with the mechanisms that have been reported to play a role in angiogenesis and in tumor development. No association with Ki67 labeling index was found. VEGF-, PDGFB-, and bFGF-mediated pathways seem to have a key role in PWT development and growth. Blockade of tyrosine kinase receptors after surgery could represent a promising therapy with the aim to reduce the PWT relapse rate and prolong the time to relapse.

Feline upper respiratory tract lymphoma: site, cyto-histology, phenotype, FeLV expression, and prognosis.

Lymphoma is the most common feline upper respiratory tract (URT) tumor. Primary nasal and nasopharyngeal lymphomas have been evaluated as distinct pathological entities; however, data on their differing clinical behavior are missing. A total of 164 endoscopic- guided URT pinch biopsies were formalin fixed and routinely processed. Imprint cytological specimens were stained with May Grünwald-Giemsa. Immunohistochemistry for anti-CD20, CD3, FeLVp27, and FeLVgp70 was performed. Prognostic significance of clinicopathological variables was investigated by univariate and multivariate analysis. Lymphoma was diagnosed in 39 cats (24%). Most cats with lymphoma were domestic shorthair (32 [82%]), were male (F/M = 0.56), and had a mean age of 10.3 years (range, 1-16 years). Lymphomas were primary nasal in 26 cats (67%), nasopharyngeal in 6 (15%), and in both locations (combined lymphomas) in 7 cats (18%). Neoplastic growth pattern was diffuse in 35 cases (90%) and nodular in 4 (10%). Epitheliotropism was observed in 10 cases (26%). Tumor cells were large in 15 cases, were small and medium in 11 cases each, and 2 had mixed cell size. Submucosal lymphoplasmacytic inflammation was observed in 23 cases (59%). Cytology was diagnostic for lymphoma in 12 of 25 cases (48%). A B-cell origin prevailed (34 [87%]). Feline leukemia virus (FeLV) p27 or gp70 antigen was detected in 21 lymphomas (54%). URT lymphomas were aggressive, with survival varying from 0 to 301 days (mean, 53 days). Epitheliotropism in 8 B-cell lymphomas (80%) and in 2 T-cell lymphomas (20%) correlated with prolonged survival. Age younger or older than 10 years had a negative prognostic value. Lymphoplasmacytic inflammation and FeLV infection may represent favoring factors for URT lymphoma development.

Canine perivascular wall tumors: high prognostic impact of site, depth, and completeness of margins.

Canine perivascular wall tumors (cPWTs) arise from vascular mural cells and are included among soft tissue sarcomas (STSs). Most prognostic studies are performed on canine STSs as a general group and regardless of their specific histotype. The aim of this study was to identify pathological parameters and profiles with prognostic impact for cutaneous/subcutaneous cPWTs. Anatomical location, type of growth, surgical margins, and size and depth of the tumor were collected in 56 cPWTs. The association between each pair of variables was evaluated by χ(2) test. Multiple correspondence analysis (MCA) was performed to describe the multivariate association of variables and was followed by cluster analysis to identify specific pathological profiles. The prognostic impact of variables and profiles was assessed by Cox regression model. Size and depth were significantly associated with increased relapse probability. Cases with complete surgical margins did not recur. Other single variables were not significantly associated with relapse. Cluster analysis on MCA considering site, depth, margins, and type of growth identified 3 pathological profiles associated with PWT relapse and having a high prognostic impact. Major prognostic factors for cPWTs were tumor size, depth of growth, and pathological profiles.

Use of electron microscopy to classify canine perivascular wall tumors.

The histologic classification of canine perivascular wall tumors (PWTs) is controversial. Many PWTs are still classified as hemangiopericytomas (HEPs), and the distinction from peripheral nerve sheath tumors (PNSTs) is still under debate. A recent histologic classification of canine soft tissue sarcomas included most histologic types of PWT but omitted those that were termed undifferentiated. Twelve cases of undifferentiated canine PWTs were evaluated by transmission electron microscopy. The ultrastructural findings supported a perivascular wall origin for all cases with 4 categories of differentiation: myopericytic (n = 4), myofibroblastic (n = 1), fibroblastic (n = 2), and undifferentiated (n = 5). A PNST was considered unlikely in each case based on immunohistochemical expression of desmin and/or the lack of typical ultrastructural features, such as basal lamina. Electron microscopy was pivotal for the subclassification of canine PWTs, and the results support the hypothesis that canine PWTs represent a continuum paralleling the phenotypic plasticity of vascular mural cells. The hypothesis that a subgroup of PWTs could arise from a pluripotent mesenchymal perivascular wall cell was also considered and may explain the diverse differentiation of canine PWTs.

Classification of canine malignant lymphomas according to the World Health Organization criteria.

A study was carried out to test the accuracy and consistency of veterinary pathologists, not specialists in hematopathology, in applying the World Health Organization (WHO) system of classification of canine lymphomas. This study represents an initiative of the ACVP Oncology Committee, and the classification has been endorsed by the World Small Animal Veterinary Association (WASVA). Tissue biopsies from cases of canine lymphoma were received from veterinary oncologists, and a study by pathologists given only signalment was carried out on 300 cases. Twenty pathologists reviewed these 300 cases with each required to choose a diagnosis from a list of 43 B and T cell lymphomas. Three of the 20 were hematopathologists who determined the consensus diagnosis for each case. The 17 who formed the test group were experienced but not specialists in hematopathology, and most were diplomates of the American or European Colleges of Veterinary Pathology. The overall accuracy of the 17 pathologists on the 300 cases was 83%. When the analysis was limited to the 6 most common diagnoses, containing 80% of all cases, accuracy rose to 87%. In a test of reproducibility enabled by reintroducing 5% of cases entered under a different identity, the overall agreement between the first and second diagnosis ranged from 40 to 87%. The statistical review included 43,000 data points for each of the 20 pathologists.

Recommended guidelines for submission, trimming, margin evaluation, and reporting of tumor biopsy specimens in veterinary surgical pathology.

Neoplastic diseases are typically diagnosed by biopsy and histopathological evaluation. The pathology report is key in determining prognosis, therapeutic decisions, and overall case management and therefore requires diagnostic accuracy, completeness, and clarity. Successful management relies on collaboration between clinical veterinarians, oncologists, and pathologists. To date there has been no standardized approach or guideline for the submission, trimming, margin evaluation, or reporting of neoplastic biopsy specimens in veterinary medicine. To address this issue, a committee consisting of veterinary pathologists and oncologists was established under the auspices of the American College of Veterinary Pathologists Oncology Committee. These consensus guidelines were subsequently reviewed and endorsed by a large international group of veterinary pathologists. These recommended guidelines are not mandated but rather exist to help clinicians and veterinary pathologists optimally handle neoplastic biopsy samples. Many of these guidelines represent the collective experience of the committee members and consensus group when assessing neoplastic lesions from veterinary patients but have not met the rigors of definitive scientific study and investigation. These questions of technique, analysis, and evaluation should be put through formal scrutiny in rigorous clinical studies in the near future so that more definitive guidelines can be derived.

Staphylococcus aureus intra-mammary infection affects the expression pattern of IL-R8 in goat.

IL-1R8 is a member of Interleukin-1 receptor family acting as a negative regulator of inflammation reliant on ILRs and TLRs activation. IL-1R8 role has never been evaluated in acute bacterial mastitis. We first investigated IL-1R8 sequence conservation among different species and its pattern of expression in a wide panel of organs from healthy goats. Then, modulation of IL-1R8 during natural and experimental mammary infection was evaluated and compared in blood, milk and mammary tissues from healthy and Staphylococcus aureus infected goats. IL-1R8 has a highly conserved sequence among vertebrates. Goat IL-1R8 was ubiquitously expressed in epithelial and lymphoid tissues with highest levels in pancreas. IL-1R8 was down-regulated in epithelial mammary cells following S. aureus infection. Interestingly it was up-regulated in leukocytes infiltrating the infected mammary tissues suggesting that it could represent a target of S. aureus immune evasion.

Pentraxin 3 is up-regulated in epithelial mammary cells during Staphylococcus aureus intra-mammary infection in goat.

Pentraxin 3 is the prototypic long pentraxin and is produced by different cell populations (dendritic cells, monocytes/macrophages, endothelial cells, and fibroblasts) after pro-inflammatory stimulation. Different studies demonstrated the up-regulation of PTX3 during mastitis in ruminants, but its role is still unknown. We first investigated the conservation of PTX3 sequence among different species and its pattern of expression in a wide panel of organs from healthy goats. We studied the modulation of PTX3 during natural and experimental mammary infection, comparing its expression in blood, milk and mammary tissues from healthy and Staphylococcus aureus infected animals. We confirmed the high conservation of the molecule among different species. Goat PTX3 was expressed at high levels in bone marrow, mammary gland, aorta, rectum, pancreas, skin and lungs. PTX3 was up-regulated in epithelial mammary cells and in milk cells after S. aureus infection, suggesting that it represents a first line of defense in goat udder.

Correlation between fine-needle aspiration cytology and histopathology in the evaluation of cutaneous and subcutaneous masses from dogs and cats.

BACKGROUND: Fine-needle aspiration cytology (FNAC) is commonly used as a diagnostic procedure to evaluate superficial and deep masses in animals. However, few studies have addressed the accuracy of FNAC in the evaluation of cutaneous and subcutaneous masses in a clinical setting. OBJECTIVE: The purpose of this study was to compare the accuracy of FNAC as compared with histopathology in the diagnosis of cutaneous and subcutaneous masses from dogs and cats. METHODS: Cytologic and histopathologic specimens obtained between 1999 and 2003 from 292 palpable cutaneous and subcutaneous masses obtained from 242 dogs and 50 cats were retrospectively evaluated. Cytologic samples were obtained by FNA and histopathologic samples were collected by surgical biopsy or at necropsy. Concordance was determined and the accuracy of FNAC for the diagnosis of neoplasia was determined using histopathology as the gold standard. RESULTS: Of 292 specimens, 49 (from 44 dogs and 5 cats) were excluded due to poor cellularity of the cytologic specimen (retrieval rate 83.2%, n = 243). A cytologic diagnosis of neoplasia was obtained in 176 cases (175 true positives and 1 false positive compared with histopathology). Sixty-seven cytology samples were classified as non-neoplastic (46 true negatives, 21 false negatives compared with histopathology). Overall, the cytologic diagnosis was in agreement with the histopathologic diagnosis in 90.9% (221/243) of cases. For diagnosing neoplasia, cytology had a sensitivity of 89.3%, a specificity of 97.9%, a positive predictive value of 99.4%, and a negative predictive value of 68.7%. CONCLUSIONS: The results of this study confirmed FNAC as a reliable and useful diagnostic procedure for the evaluation of palpable cutaneous and subcutaneous lesions in small animal practice.

Application of post-genomic techniques in dog cancer research.

Omics techniques have been widely applied to veterinary science, although mostly on farm animal productions and infectious diseases. In canine oncology, on the contrary, the use of omics methodologies is still far behind. This review presents the most recent achievement in the application of postgenomic techniques, such as transcriptomics, proteomics, and metabolomics, to canine cancer research. The protocols to recover material suitable for omics analyses from formalin-fixed, paraffin-embedded tissues are presented, and omics applications for biomarker discovery and their potential for cancer diagnostics in veterinary medicine are highlighted.

Gastric mucinous adenocarcinoma with cutaneous metastases in a dog: diagnosis by fine-needle aspiration cytology.

A 12-year-old, intact, male mixed-breed dog was presented with anorexia, vomiting and multiple cutaneous nodules on its neck, trunk and hindlimbs. Fine-needle aspiration cytology of the nodules was characterised by a pleomorphic population of cells arranged singly or in small cohesive clusters, embedded in an amorphous mucinous material stained positive by periodic acid-Schiff (PAS). Acinar structures were occasionally found. Cells appeared either small with scant basophilic cytoplasm or large with a histiocytic appearance. Large cells had cytoplasm filled with a PAS-positive granular material. A presumptive diagnosis of cutaneous metastases of a mucinous adenocarcinoma was made. A primary, gastric, signet-ring mucinous adenocarcinoma was confirmed at postmortem examination and by histopathology. To the authors' knowledge, this is the first report of a gastric mucinous adenocarcinoma with cutaneous disseminated metastases in a dog.

Diagnostic value of cytological analysis of tumours and tumour-like lesions of the oral cavity in dogs and cats: a prospective study on 114 cases.

Neoplastic or non-neoplastic masses are common findings in the oral cavity of cats and dogs. The aim of this prospective study was to compare the results of cytological examinations of lesions of the oral cavity following fine-needle aspiration (FNA), fine-needle insertion (FNI), and impression smear (IS) with histopathological results being considered as the diagnostic gold standard. In total, 85 dogs and 29 cats were included in the study. Cases were included when histology and cytology (FNA, FNI, and/or IS) were available from the same lesion; κ-agreement and accuracy between cytological and histopathological results were calculated. Eighteen cytological specimens were excluded, with a retrieval rate of 84.2%. Of the 96 samples analysed, FNA, FNI, and IS were available from 80, 76, and 73 animals, respectively. Overall, 60/67 (89.6%) and 21/29 (72.4%) lesions were neoplastic in dogs and cats, respectively, with the remaining being non-neoplastic. For all lesions, κ-values obtained by FNA, FNI, and IS were in dogs 0.83 (95% confidence interval [CI]: 0.77-0.90), 0.87 (95% CI: 0.81-0.93) and 0.75 (95% CI: 0.67-0.84), respectively, and in cats 0.92 (95% CI: 0.87-0.96), 0.92 (95% CI: 0.88-0.97) and 0.86 (95% CI: 0.79-0.92), respectively. The diagnostic accuracies of FNA, FNI, and IS in dogs with neoplasia were 98.2%, 98.1%, and 91.8%, respectively, and in cats with neoplasia were 95.6%, 95.6% and 95.8%, respectively. In conclusion, the high agreement with histopathology suggests that cytological examinations by FNI, FNA, and IS are all appropriate methods to correctly diagnose lesions of the oral cavity in dogs and cats.

Pathological characterization of primary splenic myxoid liposarcomas in three dogs.

Non-angiomatous-non-lymphomatous sarcomas (NANLs) represent 23%-34% of canine primary splenic sarcomas. Splenic liposarcomas account for 2%-6% of NANLs but myxoid variants are rarely reported and information on their behaviour is fragmentary. An 8-year-old male crossbreed (case 1), a 12-year-old female French bulldog (case 2), and an 11-year-old crossbreed (case 3) underwent splenectomy after the detection of a splenic nodule. Histology, histochemistry, immunohistochemistry, and transmission electron microscopy (TEM) were performed. Bundles of spindle-to-polygonal cells containing occasional cytoplasmic oil-red-O positive vacuoles embedded in an Alcian blue-positive extracellular matrix were observed. Aggregates of round cells were detected in cases 1 and 3. All tumours were vimentin positive and actin, desmin, Factor VIII, and S100 negative. The TEM evidenced different maturational stages of adipose cells (lipoblasts, intermediate, and undifferentiated). All the cases developed hepatic metastases and were euthanized. Disease free interval was 2 months in cases 1 and 3, and 21 months in case 2. The presence of a neoplastic embolus in case 1 and areas of round cell differentiation in cases 1 and 3 represented the sole prognostic indices.

Characterization of the diffuse mucosal associated lymphoid tissue of feline small intestine.

Characterization of the feline intestinal mucosal associated lymphoid tissue (MALT) will facilitate investigation of intestinal disease in the cat and promote the cat as an animal model for a range of human diseases which involve the intestinal lymphoid tissue. This includes inflammatory bowel disease, viral and non-viral associated intestinal lymphomas and immunodeficiency associated syndromes. Morphologic and phenotypic characterization of the normal small intestinal diffuse MALT in 22 SPF cats was performed using flow cytometry and cytology on isolated intestinal leukocytes from the intra-epithelial and lamina proprial compartments, as well as immunohistology on tissues from the feline duodenum, jejunum and ileum. The intra-epithelial compartment (IEC) was dominated by lymphocytes (>85%) which frequently contained intracytoplasmic granules. The most striking findings in the IEC were the elevated percentages of CD8 alpha+ lymphocytes (40%), presumed to express CD8 alpha alpha chains, and CD4-/CD8- (double negative) lymphocytes (44%), and the consistent presence of a minor subpopulation of CD3+/CD11d+ IELs (6%). Small percentages of CD4+ lymphocytes (10%) were observed such that the IEL CD4:CD8 ratio (0.25) was low. The LPC also contained a majority of T cells and few plasma cells. However, this compartment had reduced percentages of CD8 alpha+ lymphocytes (28%) and increased percentages of CD4+ lymphocytes (27%) relative to the IEC. However, the LPL CD4:CD8 ratio (1.0) remained low compared with the ratio in peripheral blood. In feline MALT, MHC class II expression was lower than in other peripheral lymphoid compartments. The results of this study provide important reference values for future investigations involving feline intestinal lymphocytes and demonstrates that the leukocyte distribution and phenotypic characteristics of the feline diffuse MALT appear largely similar to the murine, rat and human counterparts.

Simultaneous seminoma and interstitial cell tumour in a rabbit with a previous cutaneous basal cell tumour.

The development of spontaneous multiple tumours is a rare event in domestic rabbits. The diagnosis of a cutaneous basal cell tumour and the successive development of simultaneous bilateral testicular tumours with dissimilar histology (a seminoma and an interstitial cell tumour) are described in a vasectomized, crossbred dwarf rabbit, aged 6 years. Two cases of basalioma associated with uterine adenocarcinoma have been previously described in rabbits. A similar association between basal cell neoplasia and development of tumours (e.g., testicular and breast cancer) at cutaneous and non-cutaneous sites has been reported in man.

Nasal rhinosporidiosis in dogs: four cases from Europe and a review of the literature.

This paper describes four cases of canine rhinosporidiosis which occurred in Italy in 1994 and 1995. Four dogs with a history of exposure to the muddy environment of rice fields, developed respiratory signs. Rhinoscopy revealed nasal polypoid lesions with a characteristic gross appearance due to the presence of multiple, tiny, white-yellowish spots representing sporangia filled with spores. In cytological samples obtained by brushing, many spores were present in an inflammatory background. Histologically, the polyps consisted of fibrovascular tissue embedding sporangia in different developmental stages, and free spores which elicited a severe pyogranulomatous inflammation. All the dogs were treated surgically and the condition did not recur in two cases during a year's follow-up and in the other two cases during two years.