A spontaneous thymic carcinosarcoma in a young Sprague Dawley rat

We encountered a case of spontaneous thymic carcinosarcoma in a young Crl:CD (Sprague Dawley) rat. Grossly, a white multinodular mass replaced the thymus in the thoracic cavity. Histologically, multiple nodules were separated by fibrous stroma, and each nodule included isolated regions that were composed of epithelial or non-epithelial tumor cells. The epithelial tumor cells were relatively large and round to polygonal cells with large nuclei and weakly eosinophilic cytoplasm. These cells were cytokeratin-positive and vimentin-negative. These cells infiltrated the lungs. The non-epithelial tumor cells were poorly differentiated, small, round to spindle-shaped cells with small nuclei and basophilic cytoplasm. These cells were vimentin-positive and mostly cytokeratin-negative. Many islands of cartilage were observed near non-epithelial cells. Based on these findings, the tumor was diagnosed as a primary thymic carcinosarcoma consisting of a malignant thymoma composed of epithelial tumor cells and a mesenchymal chondrosarcoma composed of non-epithelial tumor cells.     

地顶孢霉培养物对大鼠生长性能、血清与肝脏抗氧化及免疫指标的影响

本试验旨在研究地顶孢霉培养物对大鼠生长性能、血清与肝脏抗氧化以及免疫指标的影响。选用体重相近的SD大鼠40只,随机分成5组,每组8个重复,每个重复1只大鼠。5组分别是对照组和4个不同地顶孢霉培养物剂量组(10、50、250和1 250 mg/kg BW组),连续灌胃21 d。结果表明:地顶孢霉培养物极显著提高大鼠的平均日增重(P0.01);提高了大鼠肝脏指数、胸腺指数;提高了大鼠血清中总蛋白(TP)、白蛋白(ALB)、球蛋白(GLB)和葡萄糖(GLU)含量,降低了谷丙转氨酶(ALT)、谷草转氨酶(AST)活力和低密度脂蛋白(LDL)含量;提高了血清和肝脏中谷胱甘肽过氧化物酶(GSH-Px)活力和总抗氧化能力(T-AOC),降低丙二醛(MDA)含量,同时提高了肝脏中的总超氧化物歧化酶(T-SOD)含量;提高了血清免疫球蛋白A、免疫球蛋白G和免疫球蛋白M含量,同时提高血清和肝脏中白介素-4(IL-4)含量,降低白介素-1β(IL-1β)和白介素-17(IL-17)含量。综合各项指标,地顶孢霉培养物能够提高SD大鼠平均日增重,改善血清生化指标,提高大鼠机体抗氧化能力和免疫能力,其中以250 mg/kg BW的添加量为最佳。     

A spontaneously occurring malignant ovarian Sertoli cell tumor in a young Sprague Dawley rat

Primary ovarian tumors are generally uncommon in rats used in toxicologic studies. A malignant Sertoli cell tumor was present in the ovary of a 19-week-old female Sprague Dawley rat. Macroscopically, the mass was white and firm, 10 × 13 × 17 mm in size, and located in the right ovary. Histopathologically, the mass was composed of nests of pleomorphic cells, which formed seminiferous-like tubules separated by a thin fibrovascular stroma. The tubules were lined by tumor cells, which had basally located nuclei and abundant eosinophilic and vacuolated cytoplasm. In some areas, the tumor cells were arranged in a retiform growth pattern, mimicking a rete testis/ovarii. Disseminated metastases to the surfaces of the mesentery, spleen and liver were also present. Immunohistochemically, many tumor cells were strongly positive for vimentin, estrogen receptor α and Ki 67. Some tumor cells were positive for pancytokeratin and inhibin α. These findings closely resemble those of an ovarian-derived human malignant Sertoli cell tumor. From our review of the literature, we believe this is the first report of a spontaneous malignant Sertoli cell tumor in the ovary of a young laboratory rat. This case might provide useful historical control information for rat toxicity studies.     

Erythrocyte osmotic fragility and general health status of adolescent Sprague Dawley rats supplemented with Hibiscus sabdariffa aqueous calyx extracts as neonates followed by a high‐fructose diet post‐weaning

High‐fructose diets (HFD) can cause oxidative damage to tissues including erythrocyte cell membranes. Hibiscus sabdariffa (HS) has protective antioxidant properties. Rats were used to investigate whether the consumption of HS by neonates would result in long‐term effects on their erythrocyte osmotic fragility (EOF) and general health when later fed a high‐fructose diet post‐weaning through adolescence. Eighty of four‐day‐old Sprague Dawley rat pups were divided randomly into three treatment groups. The controls (n = 27) received distilled water at 10 ml/kg b. w, while the other groups received either 50 mg/kg (n = 28) or 500 mg/kg (n = 25) of an HS aqueous calyx extract orally till post‐natal day 14. The rats in each group were weaned and divided into two subgroups; one continued on normal rat chow, and the other received fructose (20% w/v) in their drinking water for 30 days. Blood was collected in heparinised tubes and added to serially diluted (0.0–0.85%) phosphate‐buffered saline to determine the EOF. Clinical markers of health status were determined with an automated chemical analyser. HS extracts did not programme metabolism in the growing rats to alter their general health and EOF in response to the HFD.     

Spontaneous Nephroblastoma with Lung Metastasis in a Rat

This report describes a spontaneous nephroblastoma with lung metastasis in a 10-week-old male Crl:CD(SD) rat. Macroscopically, a white mass in the kidney and two white masses in the lung were observed. Histopathologically, the renal mass was located in the cortex of a kidney, and it caused pressure on the surrounding renal parenchyma. Three components could be distinguished in the tumor: blastemal, epithelial (primitive glomerular/tubular structures) and mesenchymal (neoplastic connective tissues) elements. Immunohistochemically, the tumor cells were positive for Wilms tumor 1 protein (WT1) and vimentin. Metastasis was found in the lung. Thus, the case was diagnosed as a nephroblastoma with lung metastasis.     

Case report of pulmonary metastasis in a male Wistar rat glioblastoma model

Glioblastoma (GBM) is a highly aggressive central nervous system cancer. Its extracranial metastases have rarely been reported in the past few decades. Moreover, the pathogenesis of extracranial GBM metastases remains unclear. Here, we report a case of pulmonary metastasis in a male Wistar rat of C6 GBM model. This reported Wistar male rat was one of the experimental control group without any other intervention except for C6 GBM cells orthotopic implantation. On postoperative day 15, the animal which was reported in this study showed highly cellular, pleomorphic, tumor with nuclear atypia in the brain (Ki67, approximately 65.7%) and lungs (Ki67, 49.5%). Tumor cells in the lung showed immunoreactivity for glial fibrillary acidic protein. Inflammatory CD68⁺ cell infiltration, weakly positive E-cadherin, and strongly positive staining for vimentin were observed both in tumors in the brain and lungs. Based on further morphological analysis, we speculate that the potential metastatic route into the lung might be hematogenous metastasis.     

A case of spontaneous Zymbal’s gland carcinoma with lung metastasis in an aged Fischer 344 rat

Zymbal’s gland neoplasms are induced in rats through the administration of various carcinogens, but spontaneous neoplasia is rare. This report describes a spontaneous Zymbal’s gland carcinoma with lung metastasis found in an aged male Fischer 344 rat. Macroscopically, the dome-like tumor nodule, approximately 30 mm in diameter with ulceration, was located near the ear canal of the rat. No healthy tissue or structure of Zymbal’s gland was identified on the corresponding side, while the normal salivary glands and a lacrimal gland were observed. Histologically, a large part of the tumor mass was occupied by poorly differentiated neoplastic cells, the shapes of which were oval to polygonal or fusiform. Additionally, clusters of sebaceous-like foamy cells and squamous metaplasia with prominent keratinization were observed. Tumor cells were found to metastasize to the lung; these cells displayed histological similarities, including a sebaceous gland-like pattern, to those in the primary site. The tumor cells were immunohistochemically positive for cytokeratin AE1/AE3 or vimentin but negative for CD68, S100, α-smooth muscle actin, von Willebrand factor, and desmin. Our results indicate that the tumor was a poorly differentiated Zymbal’s gland carcinoma with lung metastasis.     

Spontaneous fibrosarcoma with pleomorphic appearance in an aged brown norway rat

An 18-month-old male Brown Norway (BN) rat showed a grayish-white subcutaneous mass in the right cheek. Histologically, the mass was composed of highly pleomorphic cells producing collagen. Immunohistochemical analysis showed that the tumor cells were strongly positive for vimentin and partially positive for Ki-67; however, they were negative for ED-1, ED-2, S-100, cytokeratin, desmin and myoglobin. Ultrastructurally, the cytoplasms of the tumor cells contained well-developed rough endoplasmic reticulum. Thus, the tumor had no characteristic feature other than collagen production and was diagnosed as a fibrosarcoma.     

Multimodality imaging of primary ureteral hemangiosarcoma with thoracic metastasis in an adult dog

A 12‐year‐old spayed female standard Poodle was presented for investigation of severe hematuria. Abdominal ultrasound and thoracic and abdominal computed tomography identified severe hydronephrosis due to an obstructive ureteral mass with no evidence of metastasis. Histological examination after nephrectomy and ureterectomy confirmed an obstructive ureteral hemangiosarcoma. Forty days after surgery, the dog was presented with severe dyspnea. Survey radiographs of the thorax revealed a severe diffuse nodular interstitial pattern. Postmortem histological examination revealed pulmonary metastasis of hemangiosarcoma.