Primary chondrosarcoma in the liver of a dog

Primary chondrosarcoma was found in the quadrate lobe of the liver of a 6-year-old, intact, male Golden Retriever. At 6 months after partial hepatectomy, recurrence in the liver occurred. The dog died of its systemic metastases 10 months thereafter. Histologically, the hepatic mass revealed neoplastic chondrocytes with abundant chondroid matrix, and there were few myxoid areas where the cellularity and pleomorphism of the neoplastic cells were more prominent. The neoplastic cells were positive for periodic acid-Schiff and were immunohistochemically positive for vimentin and S-100 protein; the matrix was deeply stained for alcian blue and was metachromatic for toluidine blue stain. This tumor might be derived from pluripotent mesenchymal cells in the connective tissue of the liver. To the best of our knowledge, in all mammalians, including humans, this is the first report of extraskeletal chondrosarcoma primarily arising in the liver.     

Multiple glomus tumors of the urinary bladder in a cow associated with bovine papillomavirus type 2 (BPV-2) infection

We report a case of multiple glomus tumors associated with bovine papillomavirus type 2 (BPV-2) infection in the urinary bladder of a 13-year-old cow suffering from severe chronic enzootic hematuria. Macroscopically, multiple submucosal reddish nodules were seen swelling the vesical mucosa. Histologically, neoplastic proliferation was characterized by the presence of numerous blood vessels. These were lined by normal endothelial cells surrounded by round epithelioid cells with central nuclei, prominent nucleoli, acidophilic cytoplasm, and well-defined cytoplasmic borders. Tumor cells were distributed around open vascular lumina and in perivascular spaces. They were immunohistochemically positive for actin and vimentin and negative for cytokeratins, desmin, and factor VIII-related antigen. On the basis of these findings, this tumor was diagnosed as glomus tumor, a neoplasm not previously reported in cattle and exceedingly rare in animals. BPV-2 DNA was amplified from the formalin-fixed, paraffin-processed tissue specimens obtained by laser capture microdissection. This report widens the spectrum of mesenchymal tumors of the bovine urinary bladder. Finally, the microscopic pattern of tumor described here shares striking morphologic and immunohistochemical similarities with the angiomatous form of glomus tumor known to occur in man.     

Adenocarcinoma of the parotid salivary gland in a cow

A 6‐year‐old Girolando dairy cow was presented for evaluation of a large subcutaneous facial mass. Fine‐needle aspirates of the mass contained many neoplastic cells with high nuclear:cytoplasmic ratios arranged in sheets and loosely cohesive clusters with streaming erythrocytes and neutrophils in the background. Neoplastic cells were 13–25 μm in diameter and were round to cuboidal with variably distinct borders. Based on the signalment, anatomic location, and cytologic findings, differential diagnoses included salivary adenocarcinoma, squamous cell carcinoma, and mucoepidermoid carcinoma. The cow was euthanized and a necropsy was performed. The primary neoplasm arose from the left parotid salivary gland and meastatic tumor was found in the regional lymph nodes and lung. Histologically, the tumor was composed of anastomosing and irregular solid islets surrounded by scant stroma. Cells were negative for periodic acid‐Schiff (PAS), PAS‐diastase, and Alcian blue pH 2.5 stains, used to detect mucin. On immunohistochemical analysis, neoplastic luminal salivary gland cells expressed cytokeratin, but not S100, α‐smooth muscle actin, or vimentin. Peripheral cells of neoplastic islets were immunoreactive for p63. The final diagnosis was nonsecretory adenocarcinoma of the parotid salivary gland.     

Malignant peripheral nerve sheath tumor as a cause of chronic cardiac insufficiency in cattle

Chronic cardiac insufficiency was associated with a malignant peripheral nerve sheath tumor in a cow. An eight-year-old cow developed a progressive condition (over a period of three months) characterized by an enhanced abdominal volume, reluctance to move, a positive jugular pulse, watery diarrhea and death. At necropsy, moderate subcutaneous edema and an enhanced hepatic lobular pattern were observed. A 23x20x11 cm firm, grayish-white mass adhered to and infiltrated the right atrium. Multiple firm, yellowish-white nodules of 0.5 to 12 cm in diameter were diffusely scattered in the epicardium and parietal pericardium. Histologically, the tumor was poorly circumscribed with foci of infiltration of the myocardium. The neoplastic cells had two major histologic patterns, Antoni types A and B. Within occasional foci, pleomorphic cells with an epithelioid appearance were present in addition to multinucleated cells with periodic acid Schiff (PAS)-positive cytoplasmic globules. Foci of cartilaginous and granular differentiations were interspersed among the neoplastic cells. Multiple vessels presented wall hyalinization and tumoral embolus. Large necrotic foci with mineralization and cholesterol clefts were also observed. Immunohistochemically, the tumor was positive for S100 protein, vimentin and neuron-specific enolase labeling.     

Immunohistochemical characterization of a hepatic neuroendocrine carcinoma in a cat.

A hepatic mass was identified in a 5-year-old, female mixed-breed cat that died spontaneously after a clinical history of progressive emaciation, ptyalism, and persistent coryza. At necropsy, a 7-cm-diameter, yellow-brown, firm, multilobulated tumor was identified in the liver. Microscopically, the mass consisted of neoplastic cells arranged in small, closely packed nests within a thin fibrovascular stroma. These cells were of medium sized and polygonal, with fine argyrophilic cytoplasmic granules. Nuclei were predominantly round with finely stippled chromatin and indistinct nucleoli. Mitotic figures were numerous. Immunohistochemically, most of the neoplastic cells were immunoreactive for chromogranin A, neuron-specific enolase (NSE), and cytokeratin AE1/AE3 and weakly labeled for synaptophysin. The tumor was negative for glial fibrillary acidic protein (GFAP), vimentin, and cytokeratins 5, 6, 8, and 17. Vascular emboli and intrahepatic micrometastasis were also identified with chromogranin A. All these features were consistent with a hepatic neuroendocrine carcinoma and emphasized the importance of using a panel of antibodies to diagnose such rare tumors.     

Cystic cholangioma in the thoracic cavity of a rat

A female congenic rat produced by repeated backcrossing of Nihon rats, a model for hereditary renal cell carcinoma, to Brown Norway rats was necropsied at 24 months of age. At necropsy, a white mass about 1 centimeter in size was observed in the thoracic cavity, and the mass partly adhered to the esophagus and the diaphragm. Histologically, the mass was clearly circumscribed by connective tissue, and consisted of neoplastic cuboidal epithelial cells that showed cystic tubular proliferation. Some islands of well-differentiated hepatocytes and some vessels were observed in the mass. Immunohistochemically, the tumor cells were strongly positive for cytokeratin and partly positive for vimentin but were negative for mesothelin and Von Willebrand Factor. The positive rate for Ki-67 was 2.4%. Based on these histological and immunohistochemical evidences, we diagnosed this tumor as a cystic cholangioma that might have arisen from the ectopic hepatic tissue in the thoracic cavity.     

Mixed apocrine sweat gland tumor of the tail in a cow

A 4-year-old native-breed cow had a mass with wide areas of ulceration and hemorrhage at the base of the tail at the same level as the vulva. The tumor was 19 X 13 X 11 cm, appeared red-brown, and was firm to hard, with gritty areas apparent on cut surface. Histologically, the tumor mass was composed of multilayered epithelial cells forming glandular structures with occasional apical blebs and rare solidly packed cells in nests. The stroma included fibrous connective tissue, scattered or periglandular sheets of spindle-shaped cells resembling myoepithelium, several cartilaginous formations, and numerous irregular islands of mineralized osteoid, well-formed bone trabeculae lined by osteoblasts, and many osteoclast-like multinucleated giant cells among or near the neoplastic epithelium. Immunohistochemically, the neoplastic epithelium was positive for pan-cytokeratin (AE1/AE2) and cytokeratin 19 but was negative for cytokeratin 18. Spindle-shaped cells were stained with alpha smooth muscle actin (alphaSMA) and to a lesser extent vimentin antibodies. The cells of osteogenic lineage and spindle cells closely associated with the osteoid showed strong immunostaining for vimentin but not for alphaSMA. Immunostaining for neuron-specific enolase and S100 protein was not observed in any component of the tumor mass. These findings suggested that the origin of bone formation was undifferentiated mesenchymal cells with osteogenic potential.     

Anaplastic gangliocytoma with eosinophilic cytoplasmic granules in a cow.

In a 3-year-old Holstein cow, a tumor mass replaced the left olfactory bulb. The tumor was highly or moderately cellular, and consisted of tumor cells showing pleomorphism and anaplasia, sometimes with intracytoplasmic granules. The tumor showed weak reactivity for neurofilaments (NF) in most cells with distinct staining in a minority, and it was extremely rare to see neoplastic cells with positivity for glial fibrillary acidic protein (GFAP). The neoplastic cells displayed some ultrastructural features reminiscent of ganglionic cells, and the cytoplasmic granularity was due to the presence of numerous lysosomes. This tumor expressing both NF and GFAP may be histogenetically related to brain tumors of pluripotential cell origin in calves.     

Three equine cases of mixed hepatoblastoma with teratoid features

Hepatoblastoma was diagnosed in 3 Thoroughbreds at the University of Kentucky Livestock Disease Diagnostic Center (LDDC) since 1997. Case #1 involved a fetus with a well-demarcated, multilobulated, solitary mass that extended from the left liver lobe. Case #2 was observed in a neonate with a primary hepatic mass and multiple metastases in the skin, brain, meninges, and stylohyoid bone. Case #3 was a solitary hepatic mass incidentally discovered in a neonate at necropsy. Microscopically, the masses were similarly composed of sheets and cords of fetal and embryonal epithelial cells that frequently formed sinusoid-like structures. Intermixed with the neoplastic epithelial cells were variable amounts of hemorrhage, necrosis, osteoid, and bone. Immunohistochemically, the epithelial cells stained variably positive for alpha- fetoprotein, frequently positive for vimentin, and occasionally positive for cytokeratin. All 3 cases were diagnosed as mixed hepatoblastoma with teratoid features.     

2例犬肝胆管细胞癌的病理学诊断

肝胆管细胞癌是来源于肝胆管上皮细胞的恶性肿瘤,在多物种中都有发生。笔者运用组织病理学和免疫组织化学的方法,对2例犬肝肿瘤进行了诊断。结果显示：肝肿瘤眼观均为圆球形白色肿块,组织病理学检查肿瘤组织由呈腺管状排列的瘤细胞构成,有的腺管中央有坏死脱落的细胞,有的有黏液样物质,腺管间以薄的纤维结缔组织分隔,瘤组织有大片的坏死。瘤细胞多呈卵圆形,细胞核大、卵圆形,核分裂象多见,瘤细胞的CK19阳性表达,而CK18和AFP呈阴性表达。根据组织病理学和免疫组织化学检查结果判断,2例犬肝肿瘤为肝胆管细胞癌,本研究为犬肝肿瘤诊断积累了病理学资料。     

Metastatic Tumor in Pregnancy: Placental Germ Cell Tumor With Metastasis to the Foal

A placental mass was observed in an otherwise-healthy Quarter Horse mare; subsequently, the mare's 52-day-old foal was examined because of hind limb ataxia, urinary incontinence, and raised lesions of the distal limbs. Clinical and biochemical findings were supportive of liver disease and lumbosacral injury. Ultrasonographic evaluation of the abdomen suggested a liver mass, which was confirmed with computed tomography (CT) and determined to be neoplastic via histopathologic evaluation of a liver biopsy sample. Initial histopathology suggested a germ cell tumor. Regions of lysis affecting both femurs and third metacarpal bones and a complete oblique sagittal fracture through the body of the first sacral vertebra were present on CT. Supportive care was provided until CT confirmation of diffuse hepatic neoplasia and vertebral fracture. Necropsy revealed a large multinodular mass within the liver and a pathologic fracture of the first sacral vertebral body. Histopathologic comparison between neoplastic cells examined from the placenta and foal confirmed metastases of a germ cell tumor. Placental tumors are rare in all species; however, when noted in horses, clinicians should be aware of the possibility of metastatic spread to the foal.     

Case report: primary fibrosarcoma of the liver in a cow.

An unusual case of primary fibrosarcoma of the liver in a cow is described. The most prominent pathological findings were severe abdominal haemorrhage and neoplastic masses confined to the liver only. Histologically, spindeloid cells arranged in interlacing bundles running in various directions and numerous areas of necrosis and ossification were randomly scattered in the neoplasm.     

A case of glomus tumor in a dog

A subcutaneous mass at the digit of the left-hind limb of a 12-year-old, male mongrel dog was examined. A white firm mass, approximately 1 x 2 cm in diameter, was excided surgically. Histopathologically, the mass formed multiple nodules consisting of mixed proliferation of round epithelioid cells arranged in cord or sheet-like structures and small spindle cells forming loose irregular bundles. The epithelioid cells often showed proliferation around the blood vessels. A few giant cells scattering in the neoplastic foci were observed. The neoplastic cells were positive for alpha-smooth muscle actin and vimentin, and were negative for cytokeratin (AE1/AE3), desmin, factor-VIII related antigen, S-100 protein, and neuron specific enolase. On the basis of these findings, this tumor was diagnosed as glomus tumor. Since the present neoplasm had neither recurrence nor distal metastasis during the 12 month after surgical resection, the biological natures of the present neoplasm are supposed to be benign.     

Hepatoblastoma in a cat

Hepatoblastomas are neoplasms that originate from putative pluripotential stem cells of the liver. A hepatic mass from an 8-year-old Abyssinian cat was composed of cords and sheets of neoplastic cells, with scattered rosettes and small ductal structures. Most neoplastic cells had a pale eosinophilic cytoplasm and a round to ovoid nucleus. The tumor also had short spindle cells with an oval nucleus. Immunohistochemically, neoplastic cells were weakly positive for embryonic hepatocellular markers, such as alpha-fetoprotein and cytokeratin (CK) 8/18, but negative for the hepatocellular marker Hepatocyte Paraffin 1. The cells were also positive for CD56/neural cell adhesion molecule and for the biliary epithelial markers CK 7, CK 8/18, CK CAM5.2, and vimentin, but negative for CK 20. Some neoplastic cells expressed neuroectodermal or neuroendocrine markers, such as protein gene product 9.5 and synaptophysin, but were negative for chromogranin A and not argyrophilic by the Grimelius technique. The cat died soon after the biopsy without clinical improvement.     

Bronchiolar adenocarcinoma in a cow

An aged beef cow had a primary lung tumor that was diagnosed postmortem. Clinical signs included inappetence, weight loss, coughing, dyspnea, and reduced lung sounds. Antibiotic treatment was ineffective. The cow was euthanatized. Postmortem examination revealed numerous, firm nodules throughout both lungs. Microscopically, the pulmonary nodules contained neoplastic cells and the diagnosis was bronchiolar adenocarcinoma. A diagnosis of pulmonary neoplasia, although rare, should be considered in an aged cow with similar historical and clinical findings.     

The pagetoid variant of urothelial carcinoma in situ of urinary bladder in a cow

A case of urothelial carcinoma in situ of urinary bladder is reported in a 10-year-old cow naturally grazing on bracken-infested land. The cow suffered from enzootic hematuria for more than 5 years. The presence of bovine papillomavirus type 2 (BPV-2) DNA sequences was detected by polymerase chain reaction. The carcinoma in situ was characterized by the presence of anaplastic cells with amphophilic cytoplasm and pleomorphic nuclei containing granular, irregularly dispersed chromatin. Focal areas within the tumor contained large isolated and/or clustered cells. These cells had pale acidophilic cytoplasm, large nuclei with single or multiple nucleoli, and well-defined borders resembling Paget's cells. Immunohistochemically, all malignant cells were negative for vimentin and S-100 and positive for cytokeratins. In addition, normal and neoplastic cells expressed fragile histidine triad (FHIT) protein; surprisingly, some pagetoid cells did not. FHIT, the tumor suppressor gene at 3p14.2, encodes a protein of 147 amino acids (16.8 kd) with diadenosine triphosphate hydrolase activity and is a common target of deletions in human cancers of epithelial origin. Antibody to laminin detected a continuous epithelial basement membrane, thus clearly showing that neoplastic changes were limited to urothelial cells without invading stromal tissue. To our knowledge, this is the first report of an unusual pattern of spread of urothelial carcinoma in situ in a cow.     

Progression of an orbital T-cell rich B-cell lymphoma to a B-cell lymphoma in a dog

An 11-year-old Shetland Sheepdog was presented for exophthalmos caused by a locally extensive, poorly defined mass located behind the right eye. The primary orbital mass was identified by light microscopy and immunohistochemistry as a T-cell rich B-cell lymphoma (TCRBCL) composed predominantly of BLA.36-positive large neoplastic lymphoid cells admixed with fewer CD3- and CD79a-positive small lymphocytes. The dog was treated for lymphoma, but 6 months after presentation it was euthanatized for suspected hepatic and gastrointestinal metastasis. Gross findings revealed an enlarged liver with multiple well-demarcated, randomly distributed 0.1-1.5-cm white nodules, five firm white submucosal jejunal nodules, and ileocecal, mediastinal, and hilar lymphadenopathy. Metastatic liver lesions consisted of sheets of monomorphic large neoplastic lymphoid cells that effaced and expanded portal and centrilobular zones. These cells were morphologically similar to the large neoplastic cells of the original orbital tumor and were CD3-negative and variably BLA.36-positive, consistent with B-cell lineage. Similar cells comprised the jejunal nodules and effaced the lymph nodes. The progression of TCRBCL to a diffuse B-cell lymphoma in this case is consistent with reported human cases and has not been previously reported in the dog.     

A Case of Feline Gastrointestinal Eosinophilic Sclerosing Fibroplasia

Feline gastrointestinal eosinophilic sclerosing fibroplasia was diagnosed in an 8-month-old Scottish fold that had a primary gastrointestinal mass involving the stomach, duodenum and mesenteric lymph nodes. Histopathologically, the most characteristic feature of this mass was granulation tissue with eosinophil infiltration and hyperplasia of sclerosing collagen fiber. Immunohistochemically, large spindle-shaped cells were positive for smooth muscle actin and vimentin. This case emphasizes the importance of feline gastrointestinal eosinophilic sclerosing fibroplasia as a differential diagnosis of gastrointestinal neoplastic lesions such as osteosarcoma and mast cell tumor in cats.     

Metastatic sclerosing mesothelioma in a cow

Metastatic sclerosing mesothelioma in a crossbred cow is described. Accumulation of fluid in the abdominal cavity and solitary or coalesced nodules on the peritoneum, hepatic capsule and visceral pleurae, were observed after slaughter. Histological examination of the nodules revealed that they were composed of tubular structures supported by massive connective tissue. The lumina of the tubules were lined by solitary neoplastic mesothelial cells, or occasionally small groups of such cells were observed in the lumen. Identification of the mesothelial character of the tumours was dependent upon the histopathological and cytological characteristics of the nodules and histochemical stainings.     

Disseminated hemangiosarcoma in a cow

An antemortem diagnosis of disseminated hemangiosarcoma with extensive hepatic and splenic involvement was made in a 9-year-old cow evaluated for lethargy, weight loss, regenerative anemia, thrombocytopenia, and elevated liver enzymes. This is the first report of hemangiosarcoma in a cow with a suspected primary location of the liver and/or spleen.