一例犬前肢血管周细胞瘤的病理及免疫组化分析

血管周细胞瘤是一种软组织肉瘤,起源于毛细血管壁的周细胞。在本报道中,描述了一只11岁中华田园犬的左腿腕关节肿块。为确定肿块性质,采用影像学、细胞学和病理学检查加以诊断。X光检查显示肿瘤始于软组织,肿物界限清晰;细胞学检查显示细胞呈梭形,核仁明显,细胞核大小不一;病理组织学结果显示存在围绕血管的梭形细胞;免疫组织化学结果显示波形蛋白和α-SMA阳性表达,desmin和S-100阴性表达,肿瘤组织中PCNA阳性肿瘤细胞的数量大于25%,Masson trichrome染色显示肿瘤组织中胶原纤维的含量少。结合病理学及免疫组化确诊为血管周细胞瘤。     

Spontaneous Basal cell carcinoma of the submandibular gland in a rat

At necropsy, a white nodule (about 5 × 3 mm in size) was observed in the right submandibular gland of a 10-week-old female GALAS rat. Histopathologically, oval to spindle-shaped and pale basophilic tumor cells proliferated closely, and formed variably sized foci. The nodule partially spread into or invaded the surrounding normal tissue, and necrotic foci were recognized in the tumor. Immunohistochemically, the nuclei of the tumor cells showed a diffusely positive reaction for p63, and the cytoplasm showed a diffusely positive reaction for cytokeratin and negative reaction for αSMA, vimentin, desmin and S-100. Many tumor cells were positive for PCNA. Ultrastructurally, the tumor cells contained many tonofilaments in the cytoplasm and a few desmosomes at the intercellular portion. Based on these findings, the tumor was diagnosed as a basal cell carcinoma originating from the duct in the rat submandibular gland.     

Spontaneous adenocarcinoma with giant cell formation in the accessory sex glands in a male Sprague-Dawley rat

In this study, we report the features of an adenocarcinoma with giant cell formation spontaneously occurring in the accessory sex glands of a male 10-month-old Sprague-Dawley rat. A milky white mass was found in the region corresponding to the left seminal vesicle and the left coagulating gland. Histologically, tumor cells exhibited diverse growth patterns, including glandular/trabecular, cystic, and sheet-like growth areas. The tumor cells were pleomorphic, with round- or oval-shaped nuclei and abundant eosinophilic cytoplasm. Mitotic figures were occasionally observed. Giant cells were also prominent in the sheet-like growth area, with intracytoplasmic vacuoles containing eosinophilic material. The stroma was rich in collagen fibers and fibroblasts. Numerous inflammatory cells were observed in the glandular and cystic lumina and stroma. Immunohistochemically, the tumor cells were positive for cytokeratin AE1/AE3 and proliferating cell nuclear antigen. In the sheet-like growth area, some of the tumor cells and giant cells were positive for vimentin in the cytoplasm adjacent to the nucleus. Electron microscopy revealed that the tumor cells contained a small number of mitochondria and rough endoplasmic reticulum, and had no basement membrane or desmosome. The giant cells occasionally contained variably sized intracytoplasmic lumina and globular filamentous bodies, probably corresponding to vimentin. Considering these morphological features, the tumor was diagnosed as an adenocarcinoma with the formation of giant tumor cells originating from the male accessory sex glands.     

Ganglioglioma in the thalamus of a puppy

A solitary brain mass of a 4-month-old miniature dachshund showing seizure-like neurological signs was examined histopathologically. At necropsy a white tumor mass, replacing the thalamus, approximately 1.5 cm in diameter, was found. There was cystic space filled with yellowish pale fluid in the central area of the tumor mass. Histopathological examination revealed that the mass consisted of irregularly arranged well-differentiated neuronal and glial cells, and multifocal mineral deposits. The neuronal cells had a large clear nucleus and various amount of Nissl substances in the cytoplasm. Some neural cells were bi-nucleated. Neither mitotic figures nor proliferating cell nuclear antigen (PCNA)-positive nuclei was found in the neuronal cells. Immunostaining for glial fibrillary acidic protein (GFAP) revealed diffuse proliferation of GFAP-positive glial cells and their processes, while these glial cells did not show apparent cellular atypism, mitotic activity, or PCNA-immunoreactivity. Accordingly, the present tumor was diagnosed as ganglioglioma, and hamartomatous histogenesis might be possible.     

Involvements of Estrogen Receptor,Proliferating Cell Nuclear Antigen and p53 in Endometrial Adenocarcinoma Development in Donryu Rats

Involvements of estrogen receptor (ER)α, proliferating cell nuclear antigen (PCNA) and p53 in the uterine carcinogenesis process in Donryu rats, a high yield strain of the uterine cancer were investigated immunohistochemically. ERα was expressed in atypical endometrial hyperplasia, accepted as a precancerous lesion of the uterine tumors, as well as well- and in moderately-differentiated endometrial adenocarcinomas, and the intensities of expression were similar to those in the luminal epithelial cells of the atrophic uterus at 15 months of age. The expression, however, was negative in the tumor cells of poorly differentiated type. Good growth of implanted grafts of the poorly-differentiated adenocarcinomas in both sexes with or without gonadectomy supported the estrogen independency of tumor progression to malignancy. PCNA labeling indices were increased with tumor development from atypical hyperplasia to adenocarcinoma. The tumor cells in poorly-differentiated adenocarcinomas were positive for p53 positive but negative for p21 expression, suggesting accumulation of mutated p53. These results indicate that the consistent ERα expression is involved in initiation and promotion steps of uterine carcinogenesis, but not progression. In addition, PCNA is related to tumor development and the expression of mutated p53 might be a late event during endometrial carcinogenesis.     

Squamous cell carcinoma in a digit of the hind limb with systemic metastasis in a 17-year-old female koala

We encountered a case of cutaneous squamous cell carcinoma (SCC) in a 17-year-old female koala at a zoo. A fragile, papillary, elevated mass was found on the third digit of the right hind limb. SCC was identified histopathologically: squamous cell-like polygonal tumor cells showed a nest-like growth pattern with epidermal down growth, central keratinization and necrotic foci, and invaded dermal connective tissues. Metastatic lesions were observed in various organs, including the lung and axillary lymph node: in the lung, multiple metastatic foci similar to the primary lesion, and in the axillary lymph node, individual polygonal tumor cells infiltrated the sinusoids. Immunohistochemistry revealed that the tumor cells were positive for proliferating cell nuclear antigen, which exhibited 32–33% of labeling indices in the tumor cells. To our knowledge, this is the first report of a case of SCC in a digit of a koala.     

Expression of ski in the granulosa cells of atretic follicles in the rat ovary

The aim of the present study was to locate Ski protein, a product of cellular protooncogene c-ski, in rat ovaries in order to predict the possible involvement of Ski in follicular development and atresia. First, expression of c-ski mRNA in the ovaries of adult female rats was confirmed by RT-PCR. Then, ovaries obtained on the day of estrus were subjected to immunohistochemical analysis for Ski and proliferating cell nuclear antigen (PCNA) in combination with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Ski was expressed in granulosa cells that were positive for TUNEL, but negative for PCNA, regardless of the size of follicles. Expression of Ski in TUNEL-positive granulosa cells, but not in PCNA-positive granulosa cells, was also verified in immature hypophysectomized rats having a single generation of developing and atretic follicles by treatment with equine chorionic gonadotropin. These results indicate that Ski is profoundly expressed in the granulosa cells of atretic follicles, but not in growing follicles, and suggests that Ski plays a role in apoptosis of granulosa cells during follicular atresia.     

Cellular proliferative and telomerase activity in canine mammary gland tumors

In canine mammary tumors, we examined the telomerase activity, proliferative activity by proliferative cell nuclear antigen (PCNA) immunohistochemistry, and percentage of apoptotic cells by the deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. The relationship between these measures and histopathologic malignancy was also investigated. PCNA index was highest in malignant tumors (adenocarcinoma: 27.0%; malignant mixed tumor: 15.7%), followed by benign tumors (adenoma: 4.4%; benign mixed tumor: 5.3%), hyperplasia (2.1%), and normal mammary gland (0.9%). In adenoma and adenocarcinoma, papillary and solid types showing higher cellularity tended to have higher PCNA indices than did cystic and tubular types. Although the TUNEL index was <1% in all cases, the relationship between this measure and histopathologic diagnosis showed the same tendency as observed in PCNA immunostaining. Telomerase activity was detectable in all adenomas, benign mixed tumors, and adenocarcinomas examined. In contrast, all normal mammary glands, hyperplasias, and malignant mixed tumors were negative for telomerase. Relative telomerase activity (RTA) of adenocarcinoma (56.5) was significantly higher than that of adenoma (27.8) and benign mixed tumor (33.9), and a significant positive correlation (P < 0.001) was noted between RTA and PCNA index. No significant correlations were noted between either PCNA or TUNEL index and clinical features such as metastasis and tumor diameter. PCNA index and telomerase activity may be useful markers for judging malignancy of canine mammary tumors.     

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.     

A Case of Metastatic Adrenocortical Carcinoma Diagnosed with Steroidogenic Factor-1 in a Sprague-Dawley Rat

This report describes the morphological and immunohistochemical characteristics of an adrenocortical carcinoma with distant metastasis in a Sprague-Dawley rat. Macroscopically, a single large mass was observed in the adrenal gland, and multiple nodules were noted in the lung, liver and thyroid. Histologically, the adrenal tumor consisted of a solid growth of eosinophilic round cells with nuclear atypia. Vascular invasion was present, and multiple metastatic lesions were also observed in the lungs, liver, and mediastinal lymph nodes. Immunohistochemically, the nuclei of these tumor cells were positive for Steroidogenic Factor-1 (SF-1). In the thyroid, tumor cells histologically resembling adrenal cells were immunohistochemically negative for SF-1 but positive for calcitonin; thus the lesion was diagnosed as thyroid C-cell carcinoma. From these results, the present case was diagnosed as adrenocortical carcinoma with distant metastases. SF-1 could be a valuable marker for the differential diagnosis of adrenocortical tumors versus other endocrine tumors such as C-cell carcinoma.     

Properties of nine continuous B-cell lines established from enzootic bovine leukosis tumors.

We established 9 cell lines from 63 tumor cases of enzootic bovine leukosis and studied their properties. Cells of all lines formed small clumps and floated in culture medium, indicating growth. Four of the 9 cell lines were surface immunoglobulin (SIg)-positive, but the remaining 5 line cells were negative for SIg or, if SIg was detected, the percentage of SIg-positive cells was very low. Tests for the properties of the cells with monoclonal antibodies to lymphocytes revealed that the established line cells are B-lymphocytes. Morphological observation also revealed that they had the morphology of B-lymphoblastic cell. The results of E and EAC rosette assay were negative, but 6 of 8 cell lines were positive for EA rosetting. All the 9 cell lines reacted with MoAb C-143, which recognizes the tumor-associated antigen (TAA) of the EBL tumor cell. All 9 cell lines produced bovine leukosis virus (BLV). These results suggest that the 9 cell lines are tumor cells derived from B-lymphocytes of EBL.     

Splenic Hemangiosarcoma in a Young Sprague-Dawley Rat

The present report describes a rare case of spontaneous hemangiosarcoma in a nine-week-old male Sprague-Dawley rat. At necropsy, multiple white nodules of various sizes were observed on and within the enlarged spleen and liver and were histopathologically determined to be composed of spindle- to oval-shaped cells that showed invasive growth without encapsulation and were arranged solidly but partially in whorls or faint alveolar patterns with vascular-like spaces containing small clefts or erythrocytes in the tumor mass. Immunohistochemical analysis revealed that most of the tumor cells were strongly positive for vimentin, von Willebrand factor (vWF) and CD34 but negative for podoplanin. In addition, electron microscopic examination revealed the presence of Weibel-Palade bodies in the cytoplasm of the tumor cells. Based on these findings, this case was diagnosed as a hemangiosarcoma. The splenic masses were larger than the hepatic ones, with tumor cells mainly observed at periportal regions with tumor embolism in the liver, suggesting that primary hemangiosarcoma initially developed in the spleen before metastasizing.     

成年大鼠睾丸去精索上神经对睾丸功能及肾上腺素能受体表达的影响

试验旨在研究精索上神经（superior spermatic nerve,SSN）对睾丸功能的影响,25只成年Wistar大鼠随机分为2组,试验组左右睾丸切除精索上神经,手术30 d后两组大鼠同时处死取样分析。结果显示,睾丸去精索上神经不影响睾丸指数的大小但使附睾尾精子数极显著降低（P＜0.01）,平均日增重显著增加（P＜0.05）。增殖细胞核抗原（PCNA）免疫组织化学染色结果显示,睾丸去精索上神经不影响曲细精管精原细胞和初级精母细胞的增殖,但影响曲细精管的形态和生殖细胞的规则排列。RT-PCR结果显示,睾丸去精索上神经明显上调β1AR mRNA的表达,下调β2AR mRNA的表达;另外切除精索上神经不影响睾丸3β-羟胆固醇脱氢酶（3β-HSD）mRNA表达,但显著抑制类固醇快速调节蛋白（StAR）、胆固醇侧链裂解酶（P450scc）mRNA表达（P＜0.05）。结果表明,支配睾丸的精索上神经通过调节肾上腺素能受体β1AR和β2AR的表达及StAR和P450scc影响睾丸睾酮的合成和精子的发生。     

Gastroduodenal adenocarcinomas and rectal adenoma in a cougar (Felis concolor) infected with Helicobacter-like organisms and spirochetes

A 14-year-old female cougar died from gastroduodenal adenocarcinomas and rectal adenoma. At necropsy, polypoid tumor masses of various sizes were scattered on the mucosal surfaces of the stomach, duodenum, and rectum. Histologically, the gastric tumor was diagnosed as an intestinal type adenocarcinoma and the tumor cells metastasized to the mesenteric lymph nodes, spleen, and lung. Helicobacter-like organisms were detected in the lumina lined by foveolar epithelium. In the duodenum, the carcinoma cells were localized in the limina propria and many of them were intensely positive for proliferating cell nuclear antigen (PCNA). In contrast, the rectal adenoma had a lower number of PCNA-positive cells. In the rectum, chronic inflammation with numerous spirochetes was also noted. These results indicated that the occurrence of the gastrointestinal tumors might be associated with the bacterial infection described above.     

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.     

Casual discovery of a thoracic tumour showing histological features of undifferentiated pleomorphic sarcoma in a male Wistar laboratory rat

Sarcomas are neoplasms of mesenchymal origin, with a predominant cell population mimicking the organization of various soft tissues and/or bones. Previous categorizations also included the possibility of the presence of tissue macrophage-like (histiocytes) neoplasm cells, in a tumour described as malignant fibrous histiocytoma, but this group has been considered as a variety of undifferentiated pleomorphic sarcomas. Although this kind of malignancy is not rare in humans, only few cases have been reported in laboratory animals. We report an unusual single case of spontaneous tumour growth, detected by casual observation, in the left thoracic area of an 18-month-old male laboratory Wistar rat. Both this individual and his ancestors were not exposed to any known carcinogenic substance or radiation, thus suggesting the development of the neoplasm as a spontaneous event. The mass was extracted surgically under general anaesthesia, and slices were examined histologically and immunohistochemically, using photon microscopy. The pathologist reported the presence of a combination of fibroblasts and undifferentiated mesenchymal cells arranged in a storiform pattern. Immunohistochemistry was performed on the tissue using specific antibodies for several proliferation (Ki-67) and differentiation (S-100, CD-34, CD-68, pan-keratin, desmin and smooth muscle actin-SMA) markers. Positive reaction was observed for S-100, Ki-67, CD-68, desmin and SMA (limited) but not for CD-34 or cytokeratin.     

Spontaneous Adenosquamous Carcinoma with Rapid Growth and EMT-like Changes in the Mammary Gland of a Young Adult Female BALB/c Mouse

This study histopathologically and immunohistochemically investigated a spontaneously occurring single mass subcutaneously located in the left lower abdomen of a female BALB/cAJcl−nu/+ mouse at 10 weeks of age. The mass was about 20 × 15 × 10 mm in size after formalin fixation; nevertheless, it was not detected by clinical observations at 9 weeks of age. H&E staining revealed the tumor origin was epithelial and probably arose from the mammary gland, and the tumor cells demonstrated a squamous, acinar or polyhedral/basal pattern. A cell kinetics analysis revealed that many of the tumor cells of the squamous, acinar or polyhedral/basal component were positive for PCNA and cyclin D1, although there were a few of TUNEL-positive tumor cells in all of the components. An epithelial/mesenchymal analysis demonstrated that most of the tumor cells of the squamous and acinar components contained keratin and E-cadherin; however, most of the tumor cells of the polyhedral/basal component were less or very weakly positive for these markers. The tumor cells of the squamous component were negative for vimentin and SMA; however, many of the tumor cells of the polyhedral/basal component exhibited vimentin. In addition, expression of SMA was confirmed in some tumor cells of the acinar and basal components. Based on the microscopic and immunohistochemical characterizations, the tumor was diagnosed to be adenosquamous carcinoma that originated from the mammary gland with rapid growth, and the tumor cells demonstrated epithelial-mesenchymal transition-like changes.     

Undifferentiated Sarcoma of the Salivary Gland in a Mongolian Gerbil (Meriones unguiculatus)

A subcutaneous mass was found in the lower ventral neck region of a 55-week-old male Mongolian gerbil (Meriones unguiculatus). Histopathologically, the mass involved salivary glands and featured diffuse proliferation of pleomorphic neoplastic cells with large necrotic foci. The lesion was well demarcated from the surrounding tissue, although invasive growth to fibrous septa was occasionally observed. The neoplastic cells were mainly arranged in irregular sheets with severe cellular atypia, round to oval nuclei and varying amounts of eosinophilic cytoplasm. Mitotic figures and multinucleated giant cells were frequent. Immunohistochemical analysis revealed that the neoplastic cells were strongly positive for vimentin and S-100 and negative for NSE, cytokeratin, α-SMA, c-kit, factor VIII, CD34, α-1-antitrypsin, lysozyme and MSR-A. Based on the results, the mass was diagnosed as an undifferentiated sarcoma of the salivary gland. To the best of our knowledge, this is the first report of such a tumor in Mongolian gerbils.     

Membranous Glomerulonephropathy in a Hatano Low-avoidance Rat

Membranous glomerulonephropathy can be experimentally induced in rats, but spontaneous cases have been rarely reported. In this report, we present a typical case of spontaneous membranous glomerulonephropathy in a rat. A male Hatano low-avoidance (LAA) strain rat had a tumor mass on the right auricle, and was sacrificed at 41 weeks of age. Urinary screening by reagent strips revealed intense proteinuria. Histological tests revealed frequent presence of irregularly sized eosinophilic hyaline materials on the capillary wall and in the mesangium of renal glomeruli. Immunofluorescence revealed granular deposits of IgG, IgM, and C3 in the glomeruli. Subepithelial dense deposits were observed by electron microscopy accompanied by podocyte foot process effacement and occasional irregular thickening of the glomerular basement membrane. The rat also developed chronic lymphocytic pancreatitis, and the tumor mass on the right auricle was diagnosed as a fibrosarcoma. Screening tests for antibodies against major infectious agents and antinuclear antibody were negative. Western blot and indirect immunofluorescence analyses suggested the presence of an autoantibody against the pancreatic component. The glomerulopathy was considered an early stage of membranous glomerulonephropathy.