B. Restucci

Expression of Vascular Endothelial Growth Factor in Canine Mammary Tumors

Vascular endothelial growth factor (VEGF) is a dimeric protein that stimulates angiogenesis in vitro and in vivo by inducing endothelial cell proliferation and migration. In this immunohistochemical study, VEGF-immunolabeled cells were counted in a series of 10 benign and 40 malignant canine mammary tumors. The morphologic pattern of VEGF positivity (intensity of immunolabeling and VEGF granule size and distribution) was also evaluated. A low number of cells weakly positive for VEGF with few and small granules polarized to the luminal pole was detected in benign neoplasms. In contrast, in malignancies a high number of VEGF-positive cells had strong immunolabeling, often with large granules found diffusely in the cytoplasm. This level of immunolabeling was more pronounced in the less differentiated, more malignant phenotypes (grade 3). Macrophages, which can synthesize VEGF, were strongly positive. Stromal and myoepithelial cells were negative. VEGF data were correlated statistically with intratumoral microvessel density (number of newly formed microvessels) and both measures were greater in less differentiated malignant neoplasms, demonstrating that angiogenesis and malignancy increase together. VEGF appears to be a powerful angiogenic factor in canine mammary tumors.

Evaluation of Angiogenesis in Canine Mammary Tumors by Quantitative Platelet Endothelial Cell Adhesion Molecule Immunohistochemistry

Angiogenesis was evaluated by immunohistochemistry for platelet endothelial cell adhesion molecule (CD31) in a series of benign and malignant canine mammary neoplasms. Computer image analysis was used to measure the intratumoral microvessel density (number of microvessels per square millimeter) and the area and perimeter of immunolabeled vascular structures. A higher intratumoral microvessel density and lower values for area and perimeter were found in malignant neoplasms compared with benign tumors and among the malignant tumors, in less differentiated phenotypes and in more anaplastic histological types (solid and squamous carcinomas), most of which had metastasized. These findings are consistent with an increase in angiogenesis in multistage neoplasia. Therefore, in more anaplastic malignant neoplasms, numerous but small and often malformed new vessels can be identified. The correlation of angiogenesis data with differentiation grade and histological type of mammary neoplasms is consistent with the findings in human medicine and demonstrates that angiogenesis can also have a prognostic value in veterinary medicine.

Correlation of Nuclear Morphometric Features with Animal and Human World Health Organization International Histological Classifications of Canine Spontaneous Seminomas

The aim of this study was to correlate nuclear morphometric features with animal and human World Health Organization International Histological Classifications in canine seminomas. Twenty-three canine seminomas were classified, according to Animal World Health Organization International Histological Classification as intratubular, intratubular with signs of invasion, or diffuse and according to Human World Health Organization International Histological Classification criteria as spermatocytic and typical. The morphonuclear characteristics of tumors were quantitatively evaluated by means of digital cell image analyses of hematoxylin and eosin-stained nuclei. In particular, the mean nuclear area, mean nuclear perimeter, mean nuclear form factor, and their respective standard deviations were calculated. The relationship between the different variables and the tumor histologic types was assessed. On the basis of animal and human classification systems, statistically significant differences were observed only between intratubular seminomas with signs of invasion and the other two types and between spermatocytic and typical seminomas, respectively. In humans, it is well known that typical seminomas are more common and aggressive than spermatocytic ones. In our study, the canine seminomas classified as typical showed significantly larger and more variable nuclear area and perimeter than spermatocytic seminomas. These results support the opinion that most canine seminomas correspond to human spermatocytic seminomas and could explain the benign behavior of canine seminomas, which derive from a more differentiated type of germ cell.

Pathological changes in the bone marrow of dogs with leishmaniosis

Bone marrow aspiration smears from 15 dogs naturally infected with leishmania were evaluated. Three of the dogs showed no clinical signs, six had up to three clinical signs and six had more than three. The most common pathological features of the bone marrow were megakaryocytic dysplasia in 10 of the dogs, erythrophagocytosis in eight, erythroid dysplasia in two and emperipolesis in two. The megakaryocytic and erythroid dysplasia were probably related to an increased number of marrow macrophages producing high levels of tumour necrosis factor α and interferon γ. Six of the dogs with clinical signs showed bone marrow dysplastic features and erythrophagocytosis, suggesting that leishmaniosis could be the unique cause of both conditions.

Extranodal γδ-T-cell lymphoma in a dog with leishmaniasis

An 8-year-old intact male mongrel dog with alopecia and weight loss was referred to the Veterinary Faculty of Naples. The dog had pale mucous membranes, enlarged prescapular lymph nodes, and splenomegaly. Laboratory abnormalities included anemia, thrombocytopenia, and hyperglobulinemia. Bone marrow aspirate smears contained numerous Leishmania amastigotes and an immunofluorescent antibody titer was strongly positive (1:1280) for leishmaniasis. The dog was treated with a combination of meglumine antimoniate and allopurinol for 60 days and showed clinical improvement. Two months after the end of treatment the dog was again referred because of relapse of leishmaniasis and the presence of a firm subcutaneous mass on the medial right thigh. Based on cytologic examination of fine needle aspirates of the mass, a diagnosis of large-cell lymphoma was made. Flow cytometry of tumor cells revealed gammadelta-T-cell lymphoma with a CD5+, CD3+, TCRgammadelta+, CD4-, CD8-, CD45RA+ immunophenotype. Using nested PCR, amastigotes were not detected in the neoplastic tissue. An association between leishmaniasis and hematopoietic tumors has been described rarely. gammadelta-T cells may be involved in the host response to this parasite, and prolonged antigenic stimulation and chronic immunosuppression (typical of leishmaniasis) play a crucial role in the etiopathogenesis of T-cell lymphoma.

Nuclear morphometry in relation to lymph node status in canine mammary carcinomas

The assessment of nuclear area and nuclear shape by morphometric analysis, has been investigated in 40 canine mammary carcinomas in relation to their metastatic behaviour to regional lymph-nodes. The tumours were reviewed by two experienced pathologists blinded regarding their lymph-node status, and were classified according to the histogenetically based criteria suggested by Benjamin et al. (1999). Twenty of these tumours showed lymph-node metastases (node-positive), and the other twenty were node-negative. Node-positive tumours included 6 simple adenocarcinomas, 10 ductular carcinomas, 2 anaplastic carcinomas and 2 carcinomas in mixed tumours; node-negative tumours included 18 adenocarcinomas %96, 10 simple adenocarcinomas, 8 complex adenocarcinomas %96, and 2 carcinomas in mixed tumours. Node-positive tumours showed MNA and mean SDA values significantly higher (p<0.001) than node-negative carcinomas. Data of this study, seems to confirm the importance of an histogenetically based classification in canine mammary tumours, also suggesting that morphometry may increase our prognostic performances allowing a reproducible method for detecting individual tumours with higher metastatic potential.

Silver-stained nucleolar (Ag-NOR) cluster size in feline mammary carcinomas : lack of correlation with histological appearance, mitotic activity, tumour stage, and degree of nuclear atypia

The relationship between Ag-NOR cluster size, mitotic index, tumour stage, degree of nuclear atypia and histological appearance was evaluated in a series of feline mammary carcinomas. The mean Ag-NOR cluster area per cell in these tumours ranged from 1.86 to 6.25 microns 2 and was not related to any other parameter studied. This suggests that Ag-NOR cluster size measurement is of poor diagnostic and prognostic value for feline mammary carcinomas.

IMMUNOHISTOCHEMICAL DISTRIBUTION OF TYPE IV COLLAGENASE IN NORMAL, DYSPLASTIC AND NEOPLASTIC CANINE MAMMARY GLAND

The distribution of type IV collagenase (cIVase) was evaluated immunohistochemically in a series of normal, dysplastic and neoplastic canine mammary glands, as well as in lymph node metastases. In normal and dysplastic mammary tissues, and benign mammary tumours, cIVase was observed in myoepithelial cells, but in malignant tumours it was mainly localized in the cytoplasm of carcinoma cells and fibroblasts close to infiltrating neoplastic cells. No significant difference was observed between carcinomas of different histological sub-types. These results suggest that the distribution of cIVase is a potentially useful indicator of malignancy in canine mammary tumours.

Structural basis of cardiomyopathy in Duchenne/Becker carriers. Endomyocardial biopsy evaluation.

Dystrophin gene mutations provoke at least three diseases: ( 1) Duchenne muscular dystrophy (DMD) caused by marked dystrophin deficiency in all striated muscles; (2) Becker muscular dystrophy (BMD) caused by qualitative and/or quantitative dystrophin abnormalities in all striated muscles; and (3) X-linked dilated cardiomyopathy (XLCM) caused by qualitative dystrophin abnormalities only in myocardium. This third type of cardiomyopathy seems not to be related to familial cases of DMD or BMD. However, many Duchenne and Becker carriers can show exactly the same clinical profiles, probably arising from a similar pathogenesis. Such an apparently isolated cardiomyopathy was described by Comi et al. * in a population of females with a close relationship with subjects suffering from Duchenne or Becker muscular dystrophy. In that population 125 (59.6%) Duchenne and 15 (65.2%) Becker consultands showed signs of myocardial involvement. Since its classical definition, the pathogenesis of dilated cardiomyopathy remains unknown. It is therefore natural to assume that detailed inspection of the myocardium could be rewarding. However, the value of endomyocardial biopsy is very high in clarifying the pathogenesis of the disease. Olsen reported that biopsy of the heart was helpful in 85% of cases; biopsy confirmed the suspected clinical diagnosis in 59% of cases and disclosed unsuspected conditions in 26%. Dilated cardiomyopathy is considered an indication €or endomyocardial biopsy. It has already been used in skeletal muscle disorder to better clarify the pathogenesis of cardiac muscle abnormalities in these patients, in order to:

A case of germinoma in a limpet (Patella coerulea) (Patellogastropoda)

Germinoma is a gonadal neoplasm originating from progenitor cells in germinal epithelium. Frequently described in some populations of bivalve molluscs, to our knowledge, germinoma has never been reported in gastropods so far. In this paper we describe the histopathological findings of some atypical cellular masses, originating in the undifferentiated germ cell layer in the male gonads of a limpet (Patella coerulea), whose morphological appearance resembled that of a germ cell tumor. The abnormal, and independent growth with no evidence of maturation of the undifferentiated and atypical germ cells, the limited number of follicles involved (n<10%) and the absence of tissue invasion, supported a diagnosis of Stage 1 germinoma.