Spontaneous gastric squamous cell carcinomas and other neoplasms in Greenland collared lemmings (Dicrostonyx groenlandicus).

Malignant neoplasms were present in 39/66 Dicrostonyx groenlandicus of varying ages, examined from a laboratory colony. The presence of multiple neoplasms in some resulted in an overall average of 1.15 tumors/affected animal. Gastric squamous papillomas were present in nine, and locally invasive or metastatic gastric squamous cell carcinomas in a further 36 animals. Three mammary adenocarcinomas, one pancreatic islet cell tumor, one probable pancreatic adenocarcinoma and one adrenal cortical adenoma were also seen in lemmings with gastric tumors. Two others had mammary adenocarcinoma alone, and one animal had bilateral Harderian gland adenocarcinoma. Lesions resembling glomerulonephrosis of rats were seen in 23/51 animals whose kidneys were examined. These findings were not considered artefacts of captivity since concurrent gastric squamous cell carcinoma, mammary adenocarcinoma and glomerulonephrosis were present in the single animal examined directly from the wild at Eskimo Point, Northwest Territories.     

Spontaneous tumors of small mammals.

The most common tumor of guinea pigs is bronchogenic papillary adenoma; of hedgehogs is mammary gland adenocarcinoma; of hamsters is adrenal cortical adenoma; of gerbils is ovarian granulosa cell and theca cell tumors; of mice is pulmonary carcinoma; and of rats is mammary fibroadenoma. A relatively low incidence of tumors is described for chinchillas and hamsters, whereas the incidence of tumors is high for gerbils, hedgehogs, mice, and rats. Limited literature regarding neoplasia exists for prairie dogs, sugar gliders, and chinchillas.     

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.     

Expression of connexins 26 and 43 in canine hyperplastic and neoplastic mammary glands

Gap junctions are the only communicating junctions found in animal tissues and are composed of proteins known as connexins. Alterations in connexin expression have been associated with oncogenesis; reported studies in rodent and human mammary glands, which normally express connexins 26 and 43, confirm these alterations in malignancies. Mammary neoplasms represent the second most frequent neoplasm in dogs, and since there are no reports on the study of connexins in canine mammary glands, the present study investigated the expression of connexins 26 and 43 in normal, hyperplastic, and neoplastic mammary glands of this species, to verify if altered patterns of connexin staining are related to higher cell proliferation and malignant phenotypes. A total of 4 normal, 8 hyperplastic mammary glands, 9 benign, and 51 malignant mammary gland neoplasms were submitted for the immunostaining of connexins 26 and 43, E-cadherin, and proliferating cell nuclear antigen (PCNA). Normal, hyperplastic, and benign neoplastic mammary glands showed a punctate pattern for connexin 26 and 43 staining and an intercellular E-cadherin staining. Malignant neoplasms, especially the most aggressive cases with high cell proliferation rates, presented either fewer gap junction spots on the cell membranes or increased cytoplasmic immunostaining. Malignant tumors also expressed a less intense immunostaining of E-cadherin; the expression of this adhesion molecule is important for the transportation of connexins to cell membranes and in forming communicating gap junctions. Deficient expression of E-cadherin could be related to the aberrant connexin localization and may contribute to the malignant phenotype. In conclusion, the expression and distribution of connexins and E-cadherin are inversely correlated to cell proliferation in malignant mammary neoplasms of dogs and may well be related to their more aggressive histologic type and biologic behavior.     

Relationship between receptors for insulin-like growth factor- I, steroid hormones and apoptosis-associated proteins in canine mammary tumors

In the veterinary literature there are few data concerning the expression of insulin-like growth factor type I (IGF-IR) in the canine mammary gland tumors. The aim of the present study was the evaluation of IGF-IR expression and its correlation to the expression of estrogen receptor alpha (ERalpha) and progesterone receptor (PR), proteins: Bcl-2, Bax, p53 in canine mammary gland tumors, and also a correlation with other features: bitch's age, tumor diameter, histologic type of tumor, degree of histologic malignancy, proliferate activity. The study was done on 112 epithelial neoplasms: 21 (19%) were adenoma, 38 (34%) complex carcinoma (adenocarcinoma), 47 (42%) simple carcinoma (adenocarcinoma) and 6 (5%) solid carcinoma. Histochemistry and immunohistochemistry methods were employed. It was shown that more common and/or higher IGF-IR expression in cells of canine mammary gland tumors was related to the histologic type of cancer of worse prognostic (solid and simple carcinoma), high histologic degree of malignancy (III degrees) but the statistical analysis did not reveal any significant differences. We observed the high degree of IGF-IR expression in tumors which displayed the high ERalpha and PR expression. These results suggest the involvement of IGF-IR in the development of hormonosensitive canine mammary tumors. Additionally, the significant positive correlation between expression of IGF-IR and p53, Bax was found. Our study provides some evidence that interactions exist between the IGF-IR and these apoptosis-associated proteins may contribute to the development and progression of canine mammary gland tumors. These results require further investigations.     

Transition of Historical Control Data for High Incidence Tumors in F344 Rats

Historical control data of tumor incidence were collected from the control groups (215 animals of each sex) in four recent carcinogenicity studies that were started between 2005 to 2009 (terminally sacrificed between 2007 and 2011) at BoZo Research Center Inc. (Gotemba, Shizuoka, Japan) using Fischer 344 rats (F344/DuCrlCrlj). These data were compared to the previous historical control data (from 1990 to 2004, previously reported) in the same facility. In the results, the incidence of C-cell adenoma in the thyroid tended to increase in both sexes in recent years (30.8% for males and 24.4% for females in 2005-2009) as compared with the previous data (17.4% and 20.1% for males and 11.5% and 11.8% for females in 1990–1999 and 2000–2004, respectively). In addition, the incidences of pancreatic islet cell adenoma in males and uterine adenocarcinoma tended to increase from around 2000 and remained high in recent years (incidences of islet cell adenoma in males of 10.5%, 17.1% and 20.5% in 1990–1999, 2000–2004 and 2005–2009; incidences of uterine adenocarcinoma of 3.3%, 12.0% and 13.5% in 1990–1999, 2000–2004 and 2005–2009, respectively). There was no apparent difference in the incidence of other tumors.     

犬常见肿瘤流行病学调查及组织病理学诊断

为探讨犬常见肿瘤的发病规律，试验收集哈尔滨地区2016-2017年宠物医院部分犬肿瘤病例71例，采用组织病理学方法对犬肿瘤进行病理学诊断，并对患病动物的品种、性别、年龄、发生部位和饮食情况与肿瘤发生关系进行统计分析。结果显示，71例确诊肿瘤病例中，恶性肿瘤28例，包括鳞状上皮细胞癌3例，基底细胞癌5例，乳腺癌14例，淋巴瘤2例，肾母细胞瘤、精原细胞癌、生殖细胞癌、侵袭性血管黏液瘤各1例；良性肿瘤43例，包括良性乳腺肿瘤15例，纤维瘤10例，平滑肌瘤5例，乳头状瘤和精原细胞瘤各3例，造釉细胞瘤、耵聍腺瘤、脂肪瘤、结节样增生、性索间质细胞瘤、颗粒细胞瘤、肛周腺瘤各1例。上述病例中，乳腺和皮肤是犬肿瘤的高发部位，分别占全部患犬的40.8%和34.0%；患病犬年龄1~16岁不等，平均发病年龄为9.1岁，7岁以后是肿瘤的高发期，中老年犬仍为主要发病群体，但低龄犬发病数量上升；各品种犬均可发生肿瘤，其中杂种犬发病率最高，其次是贵宾犬和京巴犬，且主要为乳腺肿瘤；饮食习惯主要以剩饭剩菜类和肉拌饭类为主，分别占患犬总数的39%和30%；部分肿瘤类型与犬的性别、是否绝育有关，如乳腺肿瘤多发生于未绝育的老年母犬。本研究结果为犬肿瘤的流行病学及诊断提供了参考依据，对犬肿瘤的预防和诊断有一定的借鉴意义。     

山羊鼻内腺瘤和腺癌的病理学研究

发生于内蒙古自治区某地的山羊鼻内肿瘤呈地方性流行，临床上病羊初期流出大量浆液性鼻液，随后逐渐出现呼吸困难和鼻塞音，肿瘤可侵犯周围组织引起眼球突出和头颅变形，最后死于窒息。１４例山羊鼻内肿瘤的病理学研究表明，肿瘤起源于筛骨迷路粘膜的腺体（包括浆液腺和粘液腺），组织学上为腺瘤，以后可转变为腺癌，并向周围组织作浸润性生长，未见转移。２例作透射电镜检查见瘤组织有异型性，瘤组织和瘤组织内未见病毒样颗粒。发生     

脂多糖诱导哺乳期SD大鼠乳腺炎模型的建立

本试验旨在建立脂多糖(LPS)诱导哺乳期SD大鼠乳腺炎病理模型,为后续治疗乳腺炎的深入研究奠定基础。SD大鼠30只,于产后72h随机分为对照组(5只)和试验组(25只),试验组随机分为5组,各试验组大鼠经第4对乳头灌注LPS,剂量分别为10、20、30、40、50μg/侧,对照组灌注等量PBS。灌注后24h观察记录各大鼠临床症状、乳腺组织病理学变化。结果发现,在各试验组大鼠第4对乳腺均可观察到不同程度的炎症反应,且与LPS剂量呈正比例关系。结果表明,成功建立了LPS诱导哺乳期SD大鼠乳腺炎模型。     

Three neoplasms in a Eurasian otter (Lutra lutra): malignant melanoma,trichoblastoma and mammary gland adenoma

An eighteen-year-old female Eurasian otter became emaciated and died. Necropsy examination revealed nose and thoracic cutaneous masses, abdominal subcutaneous mass, and multiple nodules in the liver and lungs. Malignant melanoma was found in the nose cutaneous mass and to have metastasized to the liver, lungs, kidneys, adrenal glands, mammary glands and left mandibular lymph node. The neoplastic cells were labeled for vimentin, melanoma, and S100. The cutaneous mass in the thoracic area consisted of spindle shaped neoplastic epithelial cells and was diagnosed as trichoblastoma. Mammary gland adenoma was observed in the abdominal subcutaneous mass. This is the first report of primary three neoplasms of malignant melanoma, trichoblastoma and mammary gland adenoma in a Eurasian otter.     

The expression of intermediate filaments in canine mammary glands and their tumors

Monoclonal antibodies specific for different types of intermediate filaments (cytokeratin, vimentin, desmin and neurofilaments) were used to study the histogenesis of canine mammary glands and 57 canine mammary tumors by immunocytochemistry. The intra- and interlobular duct epithelium, acinar, and intralobular myoepithelial cells stained positively for cytokeratin. Peripheral ductal and acinar cells, as well as interstitial cells, stained positively for vimentin. A similar staining pattern was seen in adenomas, complex adenomas, benign mixed tumors, ductular carcinomas, and one myoepithelioma-like tumor. Additionally, cytokeratin positive cells were scattered interstitially in one single adenoma, most complex adenomas, some benign mixed tumors, complex carcinomas, and in the malignant mixed tumors. All stromal cells stained positively for vimentin. The fibrosarcomas were positive only for vimentin, while the following expressed both desmin and cytokeratin: epithelial-like cells in one adenoma, three complex adenomas, the myoepithelioma-like tumor, the single comedo carcinoma, two complex carcinomas, the single lobular carcinoma, one malignant mixed tumor, and three osteosarcomas. Epithelial-like cells in one adenoma, six complex adenomas, two benign mixed tumors, two complex carcinomas, the lobular carcinoma, and the malignant schwannoma stained for neurofilaments. Three tumors, one adenoma, one complex adenoma, and the lobular carcinoma expressed both desmin and neurofilaments in addition to cytokeratin and vimentin. The results show the expression of different types of intermediate filaments and indicate that there might be a stem cell origin in most of the canine mammary tumors.     

Cytomorphologic differentiation of benign and malignant mammary tumors in fine needle aspirate specimens from irradiated female Sprague–Dawley rats

Background: Fine needle aspiration (FNA) offers a rapid and minimally invasive means to distinguish malignant from benign neoplasms. However, few studies have been published regarding the cytopathology of mammary tumors in rats despite widespread use of the rat model for breast cancer formation and inhibition.
Objective: The purpose of this study was to determine the diagnostic accuracy of FNA cytology and to develop distinguishing cytologic criteria for the diagnosis of radiation-induced benign and malignant mammary tumors in rats.
Methods: In a study of radiation-induced mammary carcinogenesis, 100 Sprague–Dawley rats with cutaneous masses were randomly chosen for FNA. The aspirates were smeared, fixed, and stained with a modified Papanicolaou procedure for diagnostic evaluation. Cytologic and histologic diagnoses (benign vs malignant) were compared, and diagnostic accuracy was calculated using the histologic diagnosis as the criterion standard. FNA smears were scored semiquantitatively on a scale of 1–4 for cellularity, atypia, nuclear size, chromatin pattern, nuclear membrane thickness, nucleoli, and mitoses. The background was evaluated for necrosis, hemorrhage, inflammation, and mucosecretory material. Cytomorphologic features were compared statistically between benign and malignant tumors, based on the histologic diagnosis.
Results: The sensitivity of FNA was 92.3% and specificity was 89.4% for the detection of malignancy. However, 14% of specimens, all fibroadenomas by histology, had insufficient cells for cytologic evaluation, for an overall accuracy rate of 78.0%. Malignant tumors had significantly higher scores for all cytomorphologic features, and were significantly more likely to contain cell clusters and necrotic debris.
Conclusions: FNA is an accurate method for differentiating benign and malignant rat mammary tumors.     

Spontaneous Mammary Adenocarcinoma in a Twelve-week-old Female Sprague-Dawley Rat

Spontaneous mammary adenocarcinoma was observed in a 12-week-old female SD rat. A movable mass in the right cervical region was found at 11 weeks of age, and the rat was sacrificed the following week. The mass was located in the vicinity of the right salivary gland and measured 38 mm × 26 mm × 16 mm in gross size. It was a firm whitish mass, with a cut surface that was also whitish in appearance. Histopathologically, neoplastic cells formed glandular structures that contained secreted eosinophilic material. Ultrastructurally, similar secreted material and lipid droplets were in the cytoplasm of the neoplastic cells. Immunohistochemically, the neoplastic cells were positive for cytokeratin 8, cytokeratin 18 and estrogen receptor α. Based on these findings, the tumor was diagnosed as a mammary gland adenocarcinoma, and we therefore conclude that this tumor type can occur spontaneously in female SD rats as young as 12 weeks of age.     

Neoplasia of captive yellow sea horses (Hippocampus kuda) and weedy sea dragons (Phyllopteryx taeniolatus)

Syngnathidae is the family of fish that includes sea horses, pipefish, and sea dragons. To date, only a single publication has described neoplasia in syngnathids, a fibrosarcoma of the brood pouch in an aquarium-reared lined sea horse (Hippocampus erectus). From 1998 until 2010, the Toronto Zoo submitted 172 syngnathids for postmortem; species included the spotted or yellow sea horse (Hippocampus kuda), the pot-bellied sea horse (Hippocampus abdominalis) and the weedy sea dragon (Phyllopteryx taeniolatus). Seven neoplasms and two neoplastic-like lesions were identified from these cases. Under light microscopy, the neoplasms had morphological characteristics of a cardiac rhabdomyosarcoma, renal adenocarcinoma, renal adenoma, renal round cell tumors, which were likely lymphomas, exocrine pancreatic carcinoma, and intestinal carcinoma. Of these neoplasms, four had clear evidence of metastasis: the pancreatic and intestinal carcinomas and both round cell tumors. As syngnathids are highly fastidious animals, they can be difficult to maintain in captivity. In order to improve their husbandry, preventative and palliative care, as well as treatment, it is important to investigate and document the types of diseases affecting syngnathids.     

Immunohistochemical staining for S100 protein in the diagnosis of canine amelanotic melanoma

Formalin-fixed, paraffin-embedded tissue samples of canine amelanotic melanomas and normal canine tissues were studied immunohistochemically for the presence of S100 protein. Use of the avidin-biotin complex procedure demonstrated variable amounts of S100 protein in the tumor cell cytoplasm and nuclei in 26 of 31 tumors. S100 protein was not observed in some other common canine skin tumors stained by the avidin-biotin complex technique. These were a mast cell tumor, fibrosarcoma, mammary gland adenocarcinoma, histiocytoma, transmissible venereal tumor, and a thyroid gland adenocarcinoma. Among normal tissues the presence of S100 protein was demonstrated in chondrocytes in the trachea, myoepithelial cells in the breast, melanocytes in the skin, some sweat glands and ducts in the skin, stellate cells in the pituitary, and interdigitating reticulum cells in the lymph node and in Peyer's patches. These results indicate that the avidin-biotin complex procedure for demonstrating S100 protein is a useful diagnostic tool in the diagnosis of canine amelanotic melanoma.     

Radiation therapy in two cats with pituitary tumors

Two cats with large pituitary neoplasms (adenoma and adenocarcinoma) were treated with fractionated radiation therapy. Total doses of 40 Gy, respectively 36 Gy, were applied in 10 fractions of 4 Gy, and 3.6 Gy respectively. Side effects were minimal and transient. Anesthesia was well tolerated. Improvement of clinical signs could be observed during radiation therapy in both cats. One cat had a complete, the other a partial tumor response. One cat (suspicion of adenoma) was euthanized 1 3/4 years after therapy due to unrelated disease. No tumor was found on histopathology, however a small focal necrosis of brain tissue in the irradiated field was observed. The second animal with a pituitary adenocarcinoma was euthanized because of tumor recurrence 1 1/2 years after therapy. Radiation therapy was effective, despite the low total doses of radiation applied.     

Effect of diet or reproductive status on the histology of spontaneous pituitary tumors in female Wistar rats

Hypophyses of four groups of 50 female rats (F0--nulliparous, F0--multiparous, F1--standard diet, and F1--low protein) were examined by light microscopy and immunocytochemistry by the avidin-biotin complex method. In pituitary glands of rats fed a low protein diet, the incidence of neoplasms of the pars distalis, the number of multifocal tumors, and the degree of neoplastic cellular atypia were significantly reduced. Pituitary adenomata in rats fed a low protein diet also caused significantly less brain compression at the time of necropsy than in rats fed a standard diet. All but two neoplastic foci from the 83 tumors stained for prolactin, and 14 of these also stained for growth hormone. No differences were found in the frequency of hemorrhagic or solid patterns of tumor. These findings may reflect a reduction in pituitary tumor initiation, promotion, and/or progression in rats fed a low protein diet.     

24例20种犬肿瘤的病理组织学观察

对犬的皮脂腺瘤、肛周腺腺瘤、肛周腺癌、毛基质瘤、间叶性软骨肉瘤、腺样型基底细胞上皮瘤、囊样型基底细胞上皮瘤、水母样型基底细胞上皮瘤、混合型基底细胞上皮瘤、基底鳞状细胞上皮瘤、甲状腺腺瘤、肥大细胞瘤、组织细胞瘤、乳腺良性混合瘤(软骨腺瘤)、乳腺良性混合瘤(肌上皮腺瘤)、恶性肌上皮细胞瘤、乳腺恶性混合瘤(癌肉瘤)、汗腺囊性增生、汗腺腺瘤、汗腺癌等20种24例肿瘤(良性肿瘤14种,恶性肿瘤6种)作了详细的病理组织学描述。     

Analysis of the Pituitary-Thyroid Axis in Bilaterally Adrenalectomized or Adrenal Transplanted Rats

The percentage, distribution, shape, intensity of staining and morphometrical parameters of the pituitary TSH immunoreactive cells and the histological features of the thyroid glands, were compared between adult rats with intact adrenals, without adrenals and biadrenalectomized animals with neonatal adrenal grafts. After the removal of the adrenal glands, TSH immunoreactive cells increased in percentage and exhibited a higher complexity of the cellular outline, than that of the intact animals. The nuclear, cytoplasmic and cell areas were significantly increased. However the bigger enhancement of the cytoplasmic area relative to the nuclear area, produced a decrease in the nuclear/cell area ratio. The thyroid glands showed some histological evidences of activation. After the transplantation of neonatal adrenal glands to adult rats, several adrenocortical nodules were present in the lumen of the small bowel segment. These adrenal masses induced a great decrease in the TSH cell area, which coupled with a smaller but significant variation of the nuclear area, led to an increase in the nuclear/cell area ratio relative to that observed in adrenalectomized animals. In addition, the distribution, shape and intensity of the immunoreactive material was similar to that observed in intact animals. In this experimental group, thyroid histology was observed to be similar to that of the intact animals.