1,721,043 research outputs found
Immunohistochemical characterization of the leucocytic infiltrate associated with canine seminomas
No full textBoth canine and human seminomas are typically associated with leucocytic infiltration, the role of which remains poorly understood. In this study, leucocytes infiltrating 10 canine seminomas were characterized. Monoclonal antibodies directed against CD18, CD11a, CD11b, CD11c, CD21, CD3, CD4, CD8 and Major Histocompatibility Complex class I and II (MHC I and MHC II) were also employed. Infiltrating leucocytes were located around vessels, adjacent to the thin fibrous septa between neoplastic lobules, and were also scattered singly amongst neoplastic cells. The more profuse infiltrates often had the appearance of follicular aggregates. Immunohistochemically, all the samples showed generally similar results. Most of the infiltrating cells were positive for CD18 and CD11a. Infiltrating cells were mainly T lymphocytes (CD3þ), particularly of the CD8þ subset. B lymphocytes (CD21þ) were detectable in almost all infiltrates; in the follicular aggregates they were centrally located, whereas T lymphocytes (CD3þ) lined the periphery. CD11cþ cells were always more numerous than CD11bþ cells, demonstrating that if macrophages and antigen-presenting cells (APCs) were well represented, monocytes and granulocytes were practically absent. Almost all of the infiltrating cells were positive for both MHC I and MHC II antigens and, in nine samples, a large number of neoplastic cells expressing MHC I were detected. A few neoplastic cells expressing MHC II were observed in seven cases. The presence of CD8þ lymphocytes, together with the large number of both infiltrating and neoplastic cells expressing MHC I, suggests that the lymphocytes mediate a cytotoxic reaction against the neoplastic cells. This hypothesis may underlie the favourable prognosis frequently associated with canine seminomas
Classical and spermatocytic seminoma in the dog : histochemical and immunohistochemical findings
No full textIn the light of earlier human studies, 43 canine tumours diagnosed as seminoma were examined histologically with haematoxylin and eosin and periodic acid-Schiff (PAS) stains, and immunohistochemically with a monoclonal antibody against human placental alkaline phosphatase (PLAP). Twenty tumours were positive for both PAS and PLAP and were therefore diagnosed as classical seminoma (SE). The other 23 tumours were negative for both PAS and PLAP and were therefore diagnosed as spermatocytic seminoma (SS). Tubules with carcinoma in situ (CIS) were present in the testicular parenchyma surrounding 15 SEs and nine SSs
Pathologic and immunohistochemical findings in a feline aortic body tumor
No full textThe presence of a heart-base tumor was diagnosed by ultrasound imaging in a 10-year-old, female, domestic shorthaired cat presenting with dyspnea and pleural effusion because of the presence of a modified transudate. Hematology and clinical chemistry were unremarkable. The owner elected euthanasia. At necropsy, a locally extensive, firm, multilobulated nodule surrounded the pulmonary vein. The tumor was composed of lobules of large polygonal cells separated by a fine fibrovascular stroma. Tumor cells infiltrated the myocardium, and neoplastic emboli were present, but no metastases were macroscopically detectable. Tumor cells were immunohistochemically positive for chromogranin A, for synaptophysin and, faintly, for neuron-specific enolase and negative for vimentin, cytokeratin, alpha smooth muscle actin, glial fibrillary acidic protein, thyreoglobulin, and calcitonin. Based on histologic and immunohistochemical findings, the diagnosis of chemodectoma was made
Extramedullary conjunctival plasmacytoma in a cat
No full textPurpose: To describe a case of solitary conjunctival plasmacytoma in a cat. Methods: A
9 year-old female Domestic shorthaired cat was referred with a 3 weeks history of protrusion
of the left third eyelid. Results: Ophthalmic examination showed conjunctival hyperemia
and a smooth nodule on the bulbar aspect of the third eyelid. Globe retropulsion was normal.
Cytologic smears of the mass revealed sheets of round cells with eccentric nucleus,
characteristic cartwheel appearance, and abundant cytoplasm with clear perinuclear halo,
highly suggestive of plasmacytoma. Accurate stadiation was performed excluding clinical
signs of multiple myeloma. The third eyelid was excised and submitted for histology. Histologically,
a poorly defined neoplastic mass, 1.5 cm in diameter, expanded nictitans conjunctiva
substituting lacrimal gland. The mass was composed of dense sheets of round cells
morphologically consistent with mature plasma cells. Anisocytosis and anisokaryosis were
mild and rare binucleated giant cells were observed. Mitoses were rare. Neoplastic cells were
immunohistochemically positive for CD20 and lambda chains and negative for CD3. Based
on histological, immunophenotypical and clinical findings a diagnosis of extramedullary plasmacytoma
of the third eyelid was posed. No recurrence has been noted 5 months after surgery.
Conclusions: Conjunctival solitary extramedullary plasmacytoma is a rare tumor in
human beings. In the feline species, intraocular and orbital but not conjunctival solitary
plasmacytomas have been reported so far. Since in the cat, in contrast to human, well differentiated
myeloma commonly have extramedullary involvement, in the diagnosis of solitary
plasmacytoma it is important to rule out a myeloma-related disorder
A case of multiple corneal epithelial inclusion cysts in a dog
No full textA case of two corneal epithelial inclusion cysts affecting the left eye, in a 3 years old
female
Labrador cross was investigated. The etiopathogenesis of the cysts formation was
suspected to be
traumatic. The two masses were removed successfully by superficial keratectomy followed
by a
third eyelid flap. Histologically, both lesions were represented by cystic formations lined by
multilayered squamous epithelium, consistent with stromal inclusion of surface corneal
epithelium.
Recovery was complete and there was no recurrence at three months follow up
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