Clinical, radiological, and pathological findings of primary nasal osteosarcoma in a Libyan cat.

Background: Although bone tumors are common pathologies in companion animals, limited reports describe nasal osteosarcoma (OSA) in cats. Case description: A case of nasal OSA in a local Libyan cat was admitted to the Veterinary Teaching Hospital at the Faculty of Veterinary Medicine, University of Tripoli-Libya, with nasal swelling and discharges and facial deformity. The radiological findings revealed nasal osteolysis with the absence of evidence of lung metastasis. In addition, fungal growth was not identified in microbiological culture. Furthermore, the pathological examination has grossly revealed a destructed nasal bone due to the presence of a tumor mass, with a mucohemorrhagic nasal discharge and absence of metastasis. OSA was confirmed histopathologically. Conclusion: This report presents the clinical, radiological, and pathological findings of a primary nasal OSA in a Libyan cat with no tumor metastasis to other body organs.

Comparative histopathology and immunohistochemistry of human and canine mammary tumors.

This study aimed at establishing aspects of comparison between canine and human mammary gland tumors. In order to achieve that, 44 specimens of canine mammary tumors and 70 specimens of human breast tumors were examined in order to state points of similarity in morphology, cells of origin, behavior and existence of tissue markers. We found that the ratio of benign to malignant forms was 4.5% to 95.5% in canine samples and 45.7% to 54.3% in human samples. In both species, malignant tumors composed of infiltrating ductal cells were in the forefront despite dissimilarity in nomenclature. Other kinds of lower rate of existence included, invasive micro-papillary carcinoma, mucinous carcinoma and invasive comedo-carcinoma which have displayed similar morphology and terminology in both species. Chondroid and squamous differentiation were found in human and canine specimens. In human samples, fibro-adenoma mounted up to 30 out of 32 benign tumors (93.8%). Her-2 and Ki-67 were detected in the specimens of both species but ER was detected in human specimens only. Our findings suggest a significant degree of resemblance between certain mammary tumor in canine and human. Such findings are in support of employing dogs in research investigation for human mammary tumors.

Ceruminous gland adenocarcinoma in a domestic Persian-mix cat (Felis catus).

A nine years old Persian-mix female cat has been suffering from recurrent bilateral ceruminous gland adenocarcinoma for many years. Masses were first noticed and resected five years ago, but reoccurred later on two more occasions. The animal has usually experienced distressful ear canal problems in association with these masses. The tumor cellular morphology was reviewed, described and discussed. This article is the first in documenting ceruminous gland adenocarcinoma in a Persian-mix cat in Libya.

Accumulation of Extracellular Matrix in Advanced Lesions of Canine Distemper Demyelinating Encephalitis.

In demyelinating diseases, changes in the quality and quantity of the extracellular matrix (ECM) may contribute to demyelination and failure of myelin repair and axonal sprouting, especially in chronic lesions. To characterize changes in the ECM in canine distemper demyelinating leukoencephalitis (DL), histochemical and immunohistochemical investigations of formalin-fixed paraffin-embedded cerebella using azan, picrosirius red and Gomori`s silver stain as well as antibodies directed against aggrecan, type I and IV collagen, fibronectin, laminin and phosphacan showed alterations of the ECM in CDV-infected dogs. A significantly increased amount of aggrecan was detected in early and late white matter lesions. In addition, the positive signal for collagens I and IV as well as fibronectin was significantly increased in late lesions. Conversely, the expression of phosphacan was significantly decreased in early and more pronounced in late lesions compared to controls. Furthermore, a set of genes involved in ECM was extracted from a publically available microarray data set and was analyzed for differential gene expression. Gene expression of ECM molecules, their biosynthesis pathways, and pro-fibrotic factors was mildly up-regulated whereas expression of matrix remodeling enzymes was up-regulated to a relatively higher extent. Summarized, the observed findings indicate that changes in the quality and content of ECM molecules represent important, mainly post-transcriptional features in advanced canine distemper lesions. Considering the insufficiency of morphological regeneration in chronic distemper lesions, the accumulated ECM seems to play a crucial role upon regenerative processes and may explain the relatively small regenerative potential in late stages of this disease.