The lymph drainage of the neoplastic mammary glands in the bitch: a lymphographic study

The purpose of this investigation was to study the lymph drainage of the neoplastic mammary glands in the bitch using indirect lymphography. The main conclusions drawn from the study of 41 natural cases were as follows: the first or cranial thoracic and second or caudal thoracic neoplastic mammary glands usually drain into the ipsilateral axillary lymph nodes and rarely into the ipsilateral axillary and sternal lymph nodes, simultaneously. The third or cranial abdominal neoplastic mammary gland usually drains into the ipsilateral axillary and superficial inguinal lymph nodes simultaneously, but sometimes only cranially into the ipsilateral axillary lymph nodes. Rarely, it drains only caudally into the ipsilateral superficial inguinal and medial iliac lymph nodes, simultaneously. The fourth or caudal abdominal neoplastic mammary gland usually drains only caudally into the ipsilateral superficial inguinal lymph nodes. Rarely, it drains into the ipsilateral axillary and superficial inguinal lymph nodes simultaneously. The fifth or inguinal neoplastic mammary gland usually drains into the ipsilateral superficial inguinal lymph nodes but rarely, does it also drain into the ipsilateral popliteal lymph node and into a lymphatic plexus at the medial aspect of the ipsilateral thigh. Lymphatic connections between the neoplastic and adjacent normal mammary glands were demonstrated in only one case. The lymph drainage pattern of the neoplastic mammary glands is slightly different to that described in normal glands using the same radiographic method.     

Malignant melanoma in a Eurasian otter (Lutra lutra).

An 11-yr-old female Eurasian otter (Lutra lutra) presented with multiple cutaneous nodules identified histologically as malignant melanomas of spindle cell and epithelioid cell type. Metastases were detected in lymph nodes and liver, and the tumor, which was derived from melanocytes, showed aggressive biological behavior. Only occasional reports exist of neoplastic disease in otters.     

Hepatocellular adenoma in a Eurasian otter (Lutra lutra)

A 7-year-old female Eurasian otter (Lutra lutra) at the Seoul Grand Park, Korea, died after displaying depression, anorexia, weight loss and rough skin for several days. At necropsy, a solitary friable round mass, which was approximately 12 × 9 × 5 cm and mottled dark red and yellow, was found bulging from the right hepatic lobe. Microscopically, the nonencapsulated, poorly circumscribed mass was composed of solid sheets of neoplastic hepatocytes. In addition, numerous small tan foci, ranging from 0.5 to 1.0 cm in diameter, were evenly scattered throughout the pancreatic tissue. These foci were found to be nonencapsulated, well-demarcated hyperplastic nodules of the exocrine pancreatic gland. We observed neither intrahepatic nor extrahepatic metastases. Based on the gross and microscopic changes, we diagnosed the animal as having a hepatocellular adenoma accompanied by exocrine pancreatic nodular hyperplasia.     

Lymphatic Drainage on Healthy and Neoplasic Mammary Glands in Female Dogs: Can it Really be Altered?

The purpose of this research was to study the mammary lymphatic drainage under a macroscopic and mesoscopic view, comparing the vascular pattern of healthy and neoplasic mammary glands injected with drawing ink alcoholic and fluorescein solutions, in 46 mongrel female dogs. The results pointed out that the thoracic gland is drained by the axillary lymph centre, but in mammary neoplasia either superficial cervical or ventral thoracic lymph centres can be involved. Cranial and caudal abdominal glands may be drained by the axillary, inguinofemoral and popliteal lymph centres. However, the popliteal drainage is specific for the healthy caudal abdominal mammary gland. The inguinal gland can be drained by both inguinofemoral and popliteal lymph centres in both neoplasic and healthy conditions. Regarding the mammary lymphatic communications, this research demonstrated that neoplasic glands present more types of anastomosis (40.9%), than healthy glands (33.33%), and an increase in contralateral anastomosis (50%) compared with healthy ones (33%). Given the data, the mammary neoplasia can change the lymphatic drainage pattern in terms of lymph centres and vascular arborization, thus forming new drainage channels and recruiting a larger number of lymph nodes. Lastly, some comments were made about the severity of a specific neoplasic mammary gland and conditions to be considered before making a decision in terms of the most adequate operative procedure, and suggestions for further investigations.     

Topographie des Collecteurs Lymphatiques Mammaires de la Chienne

The topography of the lymph drainage was examined by in vivo injections of india ink into the mammary parenchyma of 73 female dogs. Only one gland was injected at a time on each side. Only the cranial abdominal mammary gland had direct drainage to the axillary as well as to the superficial inguinal nodes. The principal routes of drainage differ for each gland. The glands on each side are completely independent as regards their lymph drainage. The cranial thoracic mammary glands on each side had their own collecting duct which led to the sternal lymph nodes. The results of this study suggest to develop a new model for the surgical extirpation of mammary tumors in the bitch.     

Mammary adenocarcinoma in a male squirrel monkey (Saimiri sciureus)

A nodule was identified within the right mammary gland of a 16-year-old male squirrel monkey (Saimiri sciureus). The mass was excised and diagnosed as a mammary adenocarcinoma. The monkey developed congestive heart failure 1.5 years later and was euthanatized. At necropsy, a subcutaneous mass was found in the right axillary region. Histologically, the mass was identified as a lymph node whose architecture was effaced by neoplastic cells resembling those of the mammary tumor. Metastasis to internal organs was not observed. This is the first reported case of a mammary tumor in a New World primate and the only known case of mammary cancer in a male nonhuman primate.     

Complex mammary carcinoma with metastases to lymph nodes,subcutaneous tissue,and multiple joints in a dog

An 8‐year‐old, intact female, mixed‐breed dog presented to the Oklahoma State University Boren Veterinary Medical Teaching Hospital for evaluation of progressive lameness and joint effusion of multiple joints. Physical examination revealed joint effusion of the elbow, hock, and stifle joints bilaterally, enlarged left axillary and right popliteal lymph nodes, a subcutaneous mass over the left elbow, and a subcutaneous mass involving the left second and third mammary glands. Cytologic examination of the mammary mass, enlarged lymph nodes, and joint fluid from most affected joints revealed a monomorphic population of loosely cohesive neoplastic epithelial cells. The patient was humanely euthanized, and subsequent necropsy with histopathologic examination revealed a complex mammary carcinoma with metastases to enlarged lymph nodes, subcutaneous tissue over the left elbow, and the synovium of multiple joints. Immunohistochemical stains were performed and showed diffusely positive pan cytokeratin, CK8/18, and CK19 staining in the neoplastic luminal epithelial cells of the mammary carcinoma, synovium, and lymph nodes, and showed diffusely positive vimentin staining of the myoepithelial cells. Myoepithelial calponin positivity was diffuse in the mammary mass and lymph nodes but minimal in the synovium. Only the mammary mass showed p63 positivity. Metastatic mammary neoplasia is relatively common in dogs; however, metastasis to the synovium has only been reported once previously in the literature. This is the first case utilizing immunohistochemistry for confirmation and characterization of metastases.     

Systemic blastomycosis in a horse.

Progressive multisystemic disease caused by Blastomyces dermatitidis was diagnosed in a 17-year-old Quarter horse broodmare. The mare had been treated unsuccessfully with antibiotics for mastitis 3 months postpartum. The disease progressed to exudative cutaneous lesions affecting the ventrum, pectoral region, and limbs accompanied by weight loss across several months. Yeast bodies were observed in swabs of the cutaneous exudate, suggesting a clinical diagnosis of blastomycosis. Following referral, pleural effusion, cavitated lung lesions, and hyperproteinemia were identified, and the mare was euthanized because of poor prognosis. Necropsy revealed extensive pyogranulomas in the mammary gland, skin, subcutaneous tissues, and lungs, accompanied by thrombi in major blood vessels of the lungs and hind limbs. Histologically, pyogranulomatous inflammation was evident in many tissues, and fungal organisms were seen in sections of mammary gland, skin, subcutis, pericardium, and lung. Blastomyces dermatitidis was cultured from mammary tissue, lungs, lymph node, and an inguinal abscess. Although blastomycosis is endemic in the area of origin of the mare in northwestern Wisconsin, the disease is extremely rare in horses and hence easily misdiagnosed. Unique features of this case included the extent of mammary gland involvement and the presence of thrombi in multiple sites.     

99mTc-labeled dextran for mammary lymphoscintigraphy in dogs

Lymphoscintigraphy is the technique of choice for sentinel lymph node detection in women with early breast cancer, but there is limited information evaluating the value of this technique in animals. We investigated mammary lymphatic drainage in 25 young female mongrel dogs by intramammary injection of 18.5 MBq of 99mTc-dextran (70,000 Da). Lymph node anatomical referencing was obtained using an external marker, bone scintigraphy, or scintiscanning the body contour. Cranial and caudal thoracic mammary glands drained into the cranial sternal lymph node and axillary lymph center. The cranial thoracic mammary gland also drained into the superficial cervical lymph node in two of five animals. The cranial abdominal gland was drained by the axillary lymph center. The caudal abdominal mammary gland was drained by the superficial inguinal lymph node in all animals and simultaneously by medial iliac lymph nodes in four of five animals. In one dog, this mammary gland was also drained by the mediastinal and the superficial cervical lymph nodes. The inguinal mammary gland was drained by superficial inguinal lymph nodes and simultaneously via the medial iliac lymph node in one animal. Lymphatic communications between lymph nodes were identified in 11 of 25 (44%) animals. 99mTc-dextran mammary lymphoscintigraphy was easy and rapid to perform and may provide valuable information for further studies.     

Basosquamous carcinoma with systemic metastasis in a miniature Pinscher

Basosquamous carcinoma (BSCC) is a rare malignancy, primarily composed of basal cells with foci of squamous differentiation. It is considered to be histologically an intermediate type between basal cell carcinoma and squamous cell carcinoma, and is known to have aggressive behaviors. BSCC occurred in a 17-year-old female minipin with a history of surgical excision for a mammary tumor. The right upper hindlimb was severely enlarged to 8 x 5 cm. Cross-section showed a homogenous white to yellow-white mass compressing the surrounding muscular tissues. The tumor metastasized also to the lungs, heart, abdominal cavity, liver and salivary gland. Microscopically, basaloid cells were crowded into solid nests or lobules separated by well-developed fibrous tissues with occasional keratinizations. Since there was no skin lesions, the tumor is assumed to be originated from the formerly present tumor in mammary gland. To our literature review, this case is the first BSCC with systemic metastasis in a dog.     

Carcinoma of the mammary gland in a mare

A 17-year-old Quarter Horse mare developed rapidly progressive, bilateral, firm enlargements of both mammary glands, ventral abdominal edema, dyspnea, and neurologic signs. The horse was euthanatized, and a carcinoma of the mammary gland was diagnosed at necropsy. Microscopically, normal glandular parenchyma was replaced by neoplastic nodules, and the tumor had metastasized to most visceral organs and throughout the musculoskeletal and central nervous systems. The tumor had a solid pattern, with microglandular differentiation, and numerous syncytial sheets.     

Mast cells in canine mammary gland tumour: number, distribution and EPOR positivity

Erythropoietin (EPO)-mediated mitogenic and anti-apoptotic effects involve all the cells expressing functional receptors for EPO (EPOR), as demonstrated by in vitro and in vivo studies. EPO shows pleiotropic effects and acts as an endogenous mediator of adaptive tissue response to metabolic stress protecting tissues from different injuries. Recently, the EPO/EPOR complex has been identified in several neoplastic cell lines and solid tumours. In this study, the authors investigated the mast cells (MCs) number, distribution and their immunoreactivity for EPOR in normal, dysplastic and neoplastic canine mammary gland. The results showed that MCs were more numerous in displastic glands compared with normal and neoplastic glands. As far as the EPOR immunoreactivity is concerned, we did not observe MCs reaction on cancer, in contrast with previously published data where epithelium of neoplastic gland showed an increase in EPOR expression along with the neoplastic progression. Overall, our results might be suggestive for MCs role in oncogenesis and offer new insight regarding to the expression of EPOR in mammary gland cancer in dog.     

Invasive ductal carcinoma of the mammary gland in a mare

A 21-year-old thoroughbred mare had a 35 x 14 x 10 cm mass involving the mammary gland. Metastases were found in the kidneys, lungs, skeletal muscles, and regional lymph nodes. Histopathologic examination of the tumor revealed a ductal solid carcinoma with extensive intraductal and intralobular involvement and focal infiltration of the adjacent stroma. The intralobular neoplasms were divided into irregularly shaped islands and sheets of polygonal and spindle-shaped epithelial cells by thick or thin fibrous connective tissue bundles. The neoplastic cells had a small or moderate amount of cytoplasm that stained faintly with eosin and round or oval hyperchromatic nuclei. Immunohistochemically, the neoplastic cells were strongly positive for Lu-5, weakly positive for AE1/AE3, vimentin, and glial fibrillary acidic protein, and negative for cytokeratin 8, cytokeratin 14, alpha-smooth muscle actin, calponin, and S100. The neoplasm was diagnosed as an invasive ductal carcinoma of the mammary gland with multiple metastases.     

Expression of oestrogen and progesterone receptors in canine sebaceous gland tumours

Sebaceous gland oestrogen α (ERα) and progesterone (PR) receptor expression was examined immunohistochemically in 26 and 32 dogs respectively with sebaceous gland hyperplasia/adenomas, epitheliomas and carcinomas, and in the glands of 10 healthy controls. The mean percentage of ERα positive nuclei in control sebaceous glands was 21.31% compared with 11.5% in hyperplasia/adenoma‐type lesions, although these values were not statistically different. In sebaceous gland epitheliomas and carcinomas, positive basal cells represented 7.86% and 3.53% of neoplastic cells respectively and these mean percentages were significantly lower in epitheliomas (P < 0.024) and carcinomas (P < 0.015) than in controls. The mean percentage of PR‐positive nuclei in control sebaceous glands was 23.96%, similar to the 22.07% found in hyperplasia/adenoma‐type lesions. In sebaceous gland epitheliomas and carcinomas, positive cells were scarce and represented 13.5% and 4.06% of neoplastic cells respectively. Differences in the percentage of positive cells between normal and pathological glands reached statistical significance for carcinomas (P < 0.043). In the control group there was greater PR (P < 0.001) and ERα expression (P < 0.014) in sebaceous glands in female dogs. The PR and ERα immunoreactivity in each category of neoplastic lesions could not be analysed because sample size was too small but when all the sebaceous gland tumours were grouped and analysed, no sex difference was found. The results suggest that oestrogen and progesterone receptor expression is reduced in some canine sebaceous gland tumours. These changes may represent a contributing factor for tumour growth or simply be a consequence of tumour progression.     

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.     

乳腺中脂肪细胞的转化和更迭

雌性动物的乳腺组织是由胚胎时期的外胚层发育而来,出生时只有少量导管和皮下基质结构,而后在性成熟、妊娠和泌乳期乳腺发育达到峰值,这一特点使乳腺成为出生后唯一可以重复再生的器官。在乳腺发育到退化的循环中,乳腺的上皮细胞、基质白色脂肪细胞、棕色脂肪细胞和肌上皮细胞经历了一系列转化和更迭,脂肪细胞的动态转化反映了乳腺的功能变化。研究乳腺细胞的转化和更迭与母畜的泌乳直接相关,对延续母畜的生产效率有重要意义。本文就乳腺中脂肪细胞转化方面的最新研究进展进行综述,为深度揭示乳腺发育过程中细胞更迭的机制提供前沿研究信息。     

Fibrosarcoma affecting the mammary gland of a cow.

A highly malignant fibrosarcoma which arose in or close to the mammary gland of a 12 year old Ayrshire cow, with metastases in local lymph nodes, lungs, liver, kidney and adrenal glands has been described. The tumors were densely cellular and consisted of interweaving bands of fusiform cells with a high mitotic index. Infiltration of normal tissues and invasion of blood vessels were characteristic features. Ultrastructural study of the cells revealed mesenchymal cells with abundance of rough endoplasmic reticulum and cytoplasmic vesicles and they were closely invested with collagen fibers.     

The Mammary Blood Flow in the Cow as Measured by the Antipyrine Absorption Method

After intramammary application of 3 g antipyrine dissolved in 30 ml distilled water into each quarter the absorption of antipyrine from the udder proceeds as a first order reaction. As the injected amount is known as well as the amount of antipyrine milked out about 1 hour later can be determined, it is possible to calculate the amount absorbed at any time between injection and emptying.It is shown, that the concentrations of antipyrine in the blood from the jugular vein and external pudic artery are identical after intramammary application of antipyrine. In experiments on lateral recumbent cows it is shown that the venous blood returns from the udder via both the subcutaneous abdominal and the external pudic veins. In the standing cows blood samples were drawn from the jugular and the subcutaneous abdominal veins. The blood samples from the subcutaneous abdominal veins were drawn during manual compression of the external pudic veins to get representative concentrations of antipyrine in the total venous blood from the udder. On account of the amount of antipyrine absorbed and the difference in antipyrine concentrations between the subcutaneous abdominal veins and the jugular vein the mammary blood flow in lactating cows was found to vary between 22–101 ml/min. per 100 g gland tissue.The possibility of calculating the mammary blood flow after injection in two glands only — while the two remaining glands might be used for other studies — is shown and discussed. The influence of the individual differences in the venous anastomoses on the results is discussed, and a procedure is described to select cows suitable for experiments on mammary blood flow.     

Pelvic limb lameness due to malignant melanoma in a horse

Malignant melanoma in a 21-year-old, gray, Arabian gelding was manifested by rapidly deteriorating lameness of the right pelvic limb. A melanotic, cutaneous mass of small dimensions was identified in the left jugular furrow. Exploratory laparoscopy revealed widespread infiltration of melanotic masses into the structures of the abdominal cavity. Necropsy indicated the lameness to have resulted from infiltration of neoplastic cells into the sacral nerves, dorsal root ganglia, proximal ischiatic nerve, and gluteal muscle fibers. The primary tumor could not be identified.     

Neoplastic melanocytic pleural effusion in a Portuguese water dog

A 9-year-old castrated male Portuguese water dog was presented following incomplete excision of a malignant melanoma at the left lip commissure by the referring veterinarian. Physical examination was otherwise unremarkable. The patient was staged using thoracic radiographs, abdominal ultrasound, and fine-needle aspirates of the mandibular lymph nodes and spleen. Given the absence of any definitive evidence of metastasis, the malignant melanoma was surgically completely removed. The dog then received four melanoma vaccine doses as an adjuvant therapy and remained clinically healthy for more than 3 months after the last immunization. However, 232 days after the initial discovery of the lip mass, the dog was euthanized due to deterioration and a poor prognosis based on the presence of lung metastases and neoplastic melanocytic pleural effusion. The latter has been rarely reported in dogs, despite the high prevalence of oral malignant melanomas and the tendency of these tumors to metastasize to the lungs.