Inguinal Glands Research Articles

Systemic Infection by Methicillin-resistant Staphylococcus pseudintermedius in a Bitch

Background: Staphylococcus pseudintermedius is an opportunistic pathogen, belonging to the genus Staphylococcus. The methicillin-resistant Staphylococci have the mecA-gene, which confers them with the ability of becoming resistant to methicillin and multiple classes of antimicrobials, which makes the treatment of the affections caused by these specimens difficult. This work describes a case of systemic infection and death by methicillin-resistant S. pseudintermediusin a bitch.Case: A crossbred bitch (Canis lupus familiaris), was admitted to the University Veterinary Hospital of the Federal University of Western Bahia (HVU-UFOB). The main complaint reported by the owner was the presence of mammary nodules and constant nasal secretion. During the clinical examination was observed reactivity in the popliteal and left submandibular lymph nodes, pale mucous membranes, stomatitis, bilateral mucopurulent nasal secretion, abdominal pustules, serous secretion in the inguinal mammary gland and focal alopecia on the dorsum. On auscultation, was identified only arrhythmia and the other physiological parameters of the animal were within normality for the species. Samples of the nasal secretion and of the secretion from the abdominal pustules were collected, and sent to the Veterinary Microbiology Laboratory of the same institution. The samples collected were sown in 5% Blood Agar (BA), Sabouraud Agar (SAB) and MacConkey Agar (MCK), after 24 h was observed in BA the growth of macroscopically white colonies, with a humid aspect, creamy consistency, with presence of catalase and α-hemolysis. Microscopically, was observed the presence of Gram-positive cocci, suggestive of Staphylococcus sp. Microscopically, was observed the presence of Gram-positive cocci, suggestive of Staphylococcus sp. In the MALDI-TOF mass spectrometry, was identified S. pseudintermedius. Enrofloxacin [Enrotrat tab® 25 mg, 5 mg/kg, SID, PO, 5 days] was prescribed and a follow-up consultation was requested. Two weeks after leaving the University Veterinary Hospital, the animal was admitted in emergency and was submitted to the support protocol and died during the procedure. After the owner’s authorization, the anatomopathological examination was carried out, and fragments of the liver, lung and kidney were collected, in addition to sample of the liquid of the abdominal cavity for microbiological examination, and was evidenced the growth of S. pseudintermedius in all the specimens. The bacterium’s susceptibility to 19 antibiotics was tested, and a high degree of resistance was found, with sensitivity only to amoxicillin+ clavulanate (20-10 μg), chloramphenicol (30 μg) and vancomycin (30 μg). Given the detection of MRSP in Chromogenic Agar and in cefoxitin disks, all the specimens were MRSP positive.Discussion: The diagnosis based on the bacteriological culture and anatopathological findings were essential for the confirmation of the clinical presentation of septicemia. The isolation of S. pseudintermedius in all the analyzed samples, associated to the identification by MALDI-TOF Mass Spectrometry confirmed the clinical suspicion of systemic infection. Based on the result of the antibiogram and phenotypic tests, it was evidenced that all the isolates were MRSP positive, presenting multiple resistance to antibiotics, which may have interfered in the efficiency of the treatment. The results obtained in this report are worrying and signal the need for the implementation of phenotypical researches associated to anti-microbial susceptibility tests in bacteria isolated from animals attended in veterinary clinics and hospitals, in order to monitor and avoid the dissemination of pathogens with a multi-resistant profile.

A case of a cancroid of the clitoris and the upper third of the inner surface of the large dentary lips removed by surgery in the Gynecological Department at the Mogilev Obstetrics Department with the removal of all inguinal lymphatic glands

Regarding the frequency of cancerous lesions of the external genital organs, they are, as always, in similar cases, to a known degree they are ambiguous; But all the same, on the basis of the available data, one can go to the conclusion that both in relation to other gynecological diseases, and in relation to cancer in other organs in general and in the genital organs in particular, cancer of the external genital organs is significantly aggravated.

To the diagnosis of ureteral stones

Reinecke (according to the ref. In New Khir. Arch., 1925, No. 32) draws attention to a new sign of entrapment of stones in the lower part of the ureter, namely, to a sharp increase and strong sensitivity of the inguinal lymph glands on the same side.

Modeling of fibrocystic mastopathy in experiment on animals

Nowadays, hormonal imbalance is proven to be a factor that influences initiation of malignant and benign breast tumors. To study the aspects of participation of sex hormones in damage to organs and tissues, it may be necessary to model a common womens pathology fibrocystic disease of mammary glands characterized by the most pronounced effects of this pathogenetic factor, on experimental animals.
 Aim. To create a model of fibrocystic disease of mammary gland with the subsequent possibility of studying morphological manifestations of the disease in natural and drug-induced pathomorphism.
 Materials and Methods. The pathology was induced by intramuscular injection of 0.5 ml of 2% synestrol and 0.5 ml of 2.5% progesterone to virgin female rats on the 1st, 7th, 14th, 21st, 28th and 35th days of the experiment. For examination, histological preparations of inguinal mammary glands were made. The preparations were described and studied using morphometric analysis.
 Results. In the result of the experiment, pronounced macro- and microscopic alterations of mammary glands were found. Microscopic picture was similar to that observed in fibrocystic mastopathy in women. Almost all the morphometric parameters underwent reliable alterations in correspondence with the given pathology.
 Conclusion. A model of fibrocystic disease of mammary gland was obtained that may be used for further study of morphogenesis and methods of correction.

Magnetic resonance angiography reveals increased arterial blood supply and tumorigenesis following high fat feeding in a mouse model of triple-negative breast cancer.

Breast cancer is the second most commonly diagnosed malignancy among women globally. Past MRI studies have linked a high animal fat diet (HAFD) to increased mammary cancer risk in the SV40Tag mouse model of triple-negative breast cancer. Here, serial MRI examines tumor progression and measures the arterial blood volume feeding mammary glands in low fat diet (LFD) or HAFD fed mice. Virgin female C3(1)SV40Tag mice (n = 8), weaned at 3 weeks old, were assigned to an LFD (n = 4, 3.7 kcal/g, 17.2% kcal from vegetable oil) or an HAFD (n = 4, 5.3 kcal/g, 60% kcal from lard) group. From ages 8 to 12 weeks, weekly fast spin echo MR images and time-of-flight (TOF) MR angiography of inguinal mammary glands were acquired at 9.4 T. Following in vivo MRI, mice were sacrificed. Inguinal mammary glands were excised and fixed for ex vivo MRI and histology. Tumor, blood, and mammary gland volumes for each time point were measured from manually traced regions of interest; tumors were classified as invasive by histopathology-blinded observers. Our analysis confirmed a strong correlation between total tumor volume and blood volume in the mammary gland. Tumor growth rates from weeks 8-12 were twice as high in HAFD-fed mice (0.42 ± 0.14/week) as in LFD-fed mice (0.21 ± 0.03/week), p < 0.004. Mammary gland blood volume growth rate was 2.2 times higher in HAFD mice (0.29 ± 0.11/week) compared with LFD mice (0.13 ± 0.06/week), p < 0.02. The mammary gland growth rate of HAFD-fed mice (0.071 ± 0.011/week) was 2.7 times larger than that of LFD-fed mice (0.026 ± 0.009/week), p < 0.01. This is the first non-invasive, in vivo MRI study to demonstrate a strong correlation between an HAFD and increased cancer burden and blood volume in mammary cancer without using contrast agents, strengthening the evidence supporting the adverse effects of an HAFD on mammary cancer. These results support the potential future use of TOF angiography to evaluate vasculature of suspicious lesions.

Risk factors associated with mammary tumors in female dogs

ABSTRACT: Mammary tumors in female dogs are the most frequent and corresponds to half of the canine tumors. The objectives of this study were to determine the risk factors associated with the occurrence of mammary tumors in female dogs and to evaluate the macroscopic characteristics of these neoformations, using 386 dogs from the “Outubro Rosa Pets” events done within the cities of Uberlândia and Patos de Minas, Minas Gerais State, Brazil, in 2015 (n=194), 2016 (n=105) and 2017 (n=87). For the determination of risk factors, the binary logistic regression test (P&lt;0.05) was performed. The occurrence of mammary tumors was 23.6% (91/386). The significant risk factors identified were increased age (P&lt;0.001), overweight (P=0.048) and non-castration (P&lt;0.001) with a chance of, respectively, 1.6, 2.3 and 9.3 times for the development of mammary tumors. In dogs with mammary tumors (n=91), 153 lesions were present, of which 39 female dogs had two or more lesions (42.8%). Most of the lesions were at the caudal abdominal (M4) and inguinal (M5) mammary glands (60.13%, 92/153). Relative to the size of the lesions, it was observed that in 78% of the female dogs the lesions were determined asT1 (&lt;3cm), 16.5% were T2 (3-5cm) and 5.5% T3 (&gt;5cm). At least 15.4% (14/91) of the dogs had one of the regional lymph nodes increased. In conclusion, the occurrence of mammary tumors in the evaluated population was 23.6% and that age, overweight and non-realization of ovariohysterectomy are risk factors associated with the development of mammary tumors.

Carcinoma de células en anillo de sello de glándula mamaria en canino

Los tumores de glándula mamaria son el tipo de neoplasia más frecuente en hembras de la especie canina. Pueden presentarse como masas únicas o múltiples afectando varias glándulas mamarias, se clasifican según el tejido de origen y sus características histológicas en carcinomas, sarcomas y tumores mixtos, con frecuencia suelen presentarse varios tipos histológicos de forma simultanea afectando diferentes glándulas mamarias en el animal. Existen varios tipos de carcinomas según la clasificación de la OMS 1999 y la de Glodschmidt 2011, con valor pronóstico para el paciente. Se presenta un caso de carcinoma de células en anillo de sello en glándula mamaria de una perra de raza rottweiler, de 8 años de edad con presentación múltiple en mamas abdominales e inguinal derecha, siendo un tipo de carcinoma poco frecuente en glándula mamaria. La paciente presentó una sobrevida de 6 meses post-cirugía, con recidiva notoria a los 4 meses y una evolución de 14 meses desde la fecha de aparición del tumor.

Fetal Alcohol Exposure Alters Mammary Epithelial Cell Subpopulations and Promotes Tumorigenesis.

Fetal alcohol exposure (FAE) increases the risk of mammary tumorigenesis in adult offspring; however, the underlying mechanism remains unknown. This study tested the hypothesis that FAE shifts the mammary epithelial cell (MEC) composition toward one that promotes tumorigenesis. Pregnant Friend Virus BNIH Jacksondams bred to MMTV-Wnt1 male mice were given ad libitum access to 5% alcohol in 0.2% saccharin solution from GD9-10 and 10% alcohol in 0.2% saccharin from GD11-GD19 or 0.2% saccharin solution from GD9-GD19. Thoracic and inguinal mammary glands from wild-type (WT) and transgenic (Tg) female offspring were harvested at 5 and 10weeks of age and dissociated to yield a single cell suspension enriched for MECs for flow cytometry, mammosphere assay, and gene analysis. A subset of Tg offspring was followed for tumor formation. WT glands of FAE animals exhibited a decreased basal cell population and increased luminal: basal ratio at 10weeks of age. qRT-PCR analysis of total MECs found that Hey1 mRNA expression was increased in the WT FAE group at 10weeks of age. In Tg glands, FAE increased the luminal progenitor cell population at 5weeks of age but did not alter MEC composition at 10weeks of age. Tertiary mammosphere-forming efficiency was greater in the WT glands of FAE animals at 10weeks of age. Tumor latency was decreased in the FAE group. Flow cytometry analysis indicated that FAE females developed tumors with an increased basal cell population. These data indicate that FAE can shift MEC subpopulations, increasing the proportion of cells that are potentially vulnerable to transformation and affecting cancer risk.

Use of Biomarker Modulation in Normal Mammary Epithelium as a Correlate for Efficacy of Chemopreventive Agents Against Chemically Induced Cancers.

In both estrogen receptor/progesterone receptor-positive (ER+/PR+) human breast cancer and in ER+/PR+ cancers in the methylnitrosourea (MNU)-induced rat model, short-term modulation of proliferation in early cancers predicts preventive/therapeutic efficacy. We determined the effects of known effective/ineffective chemopreventive agents on proliferative index (PI) in both rat mammary epithelium and small cancers. Female Sprague-Dawley rats were treated with MNU at 50 days of age. Five days later, the rats were treated with the individual compounds for a period of 14 days. At that time, normal mammary tissue from the inguinal gland area was surgically removed. After removal, the rats remained on the agents for an additional 5 months. This cancer prevention study confirmed our prior results of striking efficacy with tamoxifen, vorozole, Targretin, and gefitinib, and no efficacy with metformin, naproxen, and Lipitor. Employing a separate group of rats, the effects of short-term (7 days) drug exposure on small palpable cancers were examined. The PI in both small mammary cancers and in normal epithelium from control rats was >12%. In agreement with the cancer multiplicity data, tamoxifen, vorozole, gefitinib, and Targretin all strongly inhibited proliferation (>65%; P < 0.025) in the normal mammary epithelium. The ineffective agents metformin, naproxen, and Lipitor minimally affected PI. In the small cancers, tamoxifen, vorozole, and Targretin all reduced the PI, while metformin and Lipitor failed to do so. Thus, short-term changes in the PI in either normal mammary epithelium or small cancers correlated with long-term preventive efficacy in the MNU-induced rat model.

Anatomical, Histological, and Histochemical Analyses of the Scent Glands of the Scorpion Mud Turtle (Kinosternon scorpioides scorpioides).

Fossil evidence suggests that scent glands are basal features of Testudines. However, we know little about the structure of these glands in the Brazilian Kinosternidae. In this study, we described the macroscopic anatomy, histology, and histochemistry of the scent glands of three males and three females of Kinosternon scorpioides scorpioides from the Marajó mesoregion, Pará State, Brazil. In all of the specimens analyzed, regardless of sex, we found four scent glands, including two axillary and two inguinal glands that were structurally similar to each other. Each gland consisted of a single holocrine secretory lobule, a large lumen surrounded by relatively thin glandular secretory epithelium, an adjacent narrow layer of loose connective tissue, and a thick layer of skeletal striated muscle tissue surrounded by a serous tunic. The secretory epithelium produced a characteristic malodorous yellowish substance that was passed via a single duct through a bone channel in the bridge connecting the carapace to the plastron and excreted through an outer pore in the plate of each respective gland. Histologically, the secretory epithelium presented cells with two types of secretory vacuoles. Type 1 vacuoles stained red were the largest and most frequently found, and stained positively with Periodic acid-Schiff (PAS), suggesting they contained glycoproteic complexes. Type 2 vacuoles were translucent, smaller in size and fewer in number, and negative for PAS staining. Because they are very primitive structures, scent glands must play important roles in the lives of chelonians, but their real function remains unknown. Several hypotheses suggest that they can act as protection against ectoparasites, as a repellent of predators, in addition to attracting mates and eliciting other pheromonal responses. In this study, all animals reacted by exuding malodorous substances when handled, as a form of defense. However, these are just assumptions that need to be clarified with additional studies on animal behavior. Anat Rec, 303:1489-1500, 2020. © 2019 American Association for Anatomy.

Hemorrhagic Stroke in a Dog with Anaplastic Carcinoma of the Mammary Gland

Background: anaplastic carcinoma of the mammary gland is considered a highly invasive and malignant neoplasia, which usually leads to neoplastic thrombosis and epidermal ulceration due to invasiveness of lymphatic vessels by tumor emboli. Loss of epidermal barrier predisposes to secondary bacterial infection, mainly by commensal bacteria of the skin, and septicemia can be observed in cases of systemic dissemination. Neoplastic emboli and septic thrombi can lead to vascular obstruction, which can predispose to infarction in multiple organs. The aim of this case report is to describe a case of hemorrhagic stroke in a dog with anaplastic carcinoma of the mammary gland.Case: a 12-year-old, mixed breed, female spayed canine presented with mammary tumor with plaque formation, associated with skin ulceration which extended to the medial region of pelvic limbs. The animal also displayed neurologic clinical signs characterized by stupor, opisthotonos and apathy. Due to poor prognosis, the canine was euthanized and submitted to necropsy. During external examination, the animal was in a good body condition, had moderately pale mucosae, and it was noted a nodular plaque in the abdominal ventral area extending from thoracic to inguinal mammary gland. The mass was firm and white, extensively ulcerated, and extending from the thoracic to inguinal mammary gland. There was a well circumscribed area of infarction in the spleen and kidney. In the cerebral cortex it was observed an extensive area of hemorrhage with adhered blood clot from frontal to temporal lobe. There were multiple well circumscribed, firm, and white areas in the myocardium. Histologically, the neoplastic proliferation was composed by epithelial cells with high pleomorphism, features of malignancy, and no delimitations, leading to the diagnosis of anaplastic carcinoma of the mammary gland. Admixed with tumor cells there were multiple areas of hemorrhage, necrosis and thrombosis. In the cerebral cortex there was a focally extensive area of hemorrhage, multifocal thrombosis, abundant amount of gitter cells, and moderate perivascular inflammatory infiltrate of lymphocytes. There was neoplastic infiltrate in the bladder, adrenal glands, and lungs. There were multiple areas of necrosis and thrombosis in spleen and heart. Bacterial examination was performed in fragments of cerebral cortex and kidney, and Staphylococcus pseudintermedius was isolated.Discussion: anaplastic carcinoma of the mammary gland has an epithelial origin and is considered the most malignant neoplasm with worst prognosis due to its characteristic of high cellular pleomorphism and the ability of invasiveness of vessels and adjacent tissues. Therapeutic options are scarce and palliative, and surgical removal is not indicated. Dermal ulceration usually is infected by opportunistic bacteria that can lead to inflammation and pain, and treatment in these cases is focused on pain management with analgesics. The bacterial infection can evolve to septicemia with decrease of endogenous anticoagulants and consequent blood hypercoagulability. Moreover, studies demonstrate the higher risk of clotting abnormalities when associated to progression of mammary carcinomas, which includes anaplastic carcinoma of the mammary gland. In this study, two causes which may have led to thromboembolism and cerebral hemorrhage are discussed: septicemia after invasion of lymphatic vessels by the anaplastic carcinoma or hypercoagulability caused by the systemic neoplasia, which could have reduce the blood flow to vessels of the cerebral cortex.

The sexual dimorphic inguinal glands of the frog species Ololygon centralis (Anura: Hylidae) at light and transmission electron microscopy

The anuran skin characteristically has different types of glands, most of which are microscopic and are spread throughout the skin. Some species have specialized regions where glands agglomerate, forming macroglands. The description of the external morphology ofOlolygoncentralis(Pombal &amp;amp; Bastos, 1996) revealed the presence of an inguinal gland.Ololygoncentralisis the only species of the genus that has a macrogland. The present study found these inguinal macroglands to be present only on male specimens, thus characterizing it as a sexually dimorphic skin gland. Microscopic analysis revealed that these glands are composed of many syncytial units involved by myoepithelial cells. The center of the syncytium is full of a proteinaceous secretion with a basic pH and the absence of sugar residues. Similar glands observed in other anuran species have been associated with pheromone production, suggesting that the inguinal glands described forO.centralismales may have a similar function.

Immunohistochemical and ultrastructural evidence for telocytes in the different physiological stages of the female rat mammary gland

IntroductionTelocytes (TCs) are recently described to integrate a variety of different cells.Aim of the work.The aim was to investigate the presence of TCs in the rat mammary gland at its different physiological stages. Material and methodsTwenty four adult female albino rats were classified into 4 groups: resting, mid-pregnancy, lactating, and involution groups. Inguinal mammary glands were processed for immunohistochemical and transmission electron microscopic (TEM) examination. ResultsTCs were immune-positive for c-kit and CD34 and showed significant differences in the different studied groups indicating variable roles at the different stages. TEM results characterized TCs by its shape and the long slender and moniliform telopodes linking the cells into stromal networks. The extracellular exosomes, homo-cellular synapsis and hetero-cellular synapsis were observed. ConclusionOur study provides evidence for the presence of TCs in all stages of the gland; not only in the resting stage as proved by other studies, but with immune-labeling differences suggesting different structural and physiological roles of TCs according to the stage requirements. These functions might via controlling the proliferation during pregnancy and lactation and the involution of the gland after weaning. Thus, more future functional studies of TCs will be important to help understanding the mechanism by which TCs contribute to tissue homeostasis concerning the role of the stromal/epithelial interactions in mammary gland biology and pathology including breast cancer which would be revolutionary for future therapeutic applications.

Epidemiology of Canine Mammary Gland Tumours in Espírito Santo, Brazil

Epidemiology of Canine Mammary Gland Tumours in Espírito Santo, Brazil

Magnetic Resonance Angiography Shows Increased Arterial Blood Supply Associated with Murine Mammary Cancer.

Breast cancer is a major cause of morbidity and mortality in Western women. Tumor neoangiogenesis, the formation of new blood vessels from pre-existing ones, may be used as a prognostic marker for cancer progression. Clinical practice uses dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to detect cancers based on increased blood flow and capillary permeability. However, DCE-MRI requires repeated injections of contrast media. Therefore we explored the use of noninvasive time-of-flight (TOF) MR angiography for serial studies of mouse mammary glands to measure the number and size of arteries feeding mammary glands with and without cancer. Virgin female C3(1) SV40 TAg mice (n=9), aged 18-20 weeks, were imaged on a 9.4 Tesla small animal scanner. Multislice T2-weighted (T2W) images and TOF-MRI angiograms were acquired over inguinal mouse mammary glands. The data were analyzed to determine tumor burden in each mammary gland and the volume of arteries feeding each mammary gland. After in vivo MRI, inguinal mammary glands were excised and fixed in formalin for histology. TOF angiography detected arteries with a diameter as small as 0.1 mm feeding the mammary glands. A significant correlation (r=0.79; p< 0.0001) was found between tumor volume and the arterial blood volume measured in mammary glands. Mammary arterial blood volumes ranging from 0.08 mm3 to 3.81 mm3 were measured. Tumors and blood vessels found on in vivo T2W and TOF images, respectively, were confirmed with ex vivo histological images. These results demonstrate increased recruitment of arteries to mammary glands with cancer, likely associated with neoangiogenesis. Neoangiogenesis may be detected by TOF angiography without injection of contrast agents. This would be very useful in mouse models where repeat placement of I.V. lines is challenging. In addition, analogous methods could be tested in humans to evaluate the vasculature of suspicious lesions without using contrast agents.

Effect of high-fat diet feeding and associated transcriptome changes in the peak lactation mammary gland in C57BL/6 dams.

Maternal consumption of a high-fat diet (HFD) during pregnancy has established adverse effects on the developing neonate. In this study, we aimed to investigate the effect of an HFD on the murine mammary gland during midlactation. Female C57BL/6J mice were placed on either a low-fat diet (LFD/10% fat) or HFD (60% fat) from 3 wk of age through peak lactation (lactation day 11/L11). After 4 wk of consuming either the LFD or HFD, female mice were bred. There were no significant differences in milk yield between treatment groups, which was measured from L1 to L9. On L10, mice were subjected to an overnight fast and then euthanized on the morning of L11. Total RNA was isolated from inguinal mammary glands for whole transcriptome sequencing. We found 628 genes that were differentially expressed between the treatment groups. Notably, HFD feeding resulted in expression alterations of genes involved in collagen and cytoplasmic components. Additionally, genes related to inflammatory and immune responses were also impacted. Differential expression in gene transcript isoforms between the treatment groups was detected in three genes related to mammary duct development. This study sheds light as to how an HFD may affect the mammary gland transcriptome during midlactation.

B-mode and contrast-enhanced ultrasonography of the mammary gland during the estrous cycle of dogs

Pathology of the mammary gland is a common health issue in dogs and includes neoplasia, cysts, inflammation and infection. The use of the B-mode (US) and contrast-enhanced (CEUS) ultrasonography may aid in the diagnosis. Previous studies are currently lacking of the ultrasonic images of the mammary gland of healthy bitches in different stages of the estrous cycle and associated normal blood perfusion patterns. The purpose, therefore, was to describe the normal B-mode US and CEUS images of the mammary gland and inguinal lymph node, in six intact female beagles during five different stages of the estrous cycle (proestrus, estrus, early and late diestrus and anestrus). Within the same stage of the estrous cycle, the size (thickness) of the caudal mammary glands increased. During early and late diestrus, all mammary glands increased in thickness and had an increased heterogeneous B-mode ultrasonic appearance. The mammary glands had a heterogeneous, disorganized perfusion pattern when assessed using CEUS. For the cranial abdominal mammary gland, the area under the curve and the mean transit time increased between estrus and late diestrus and decreased between late diestrus and anestrus. For the inguinal mammary gland, only the time to peak was longer during the periods of anestrus compared to estrus whereas all the other contrast parameters did not change during the estrous cycle. In conclusion, hormonal influences cause major changes in the size, appearance and blood perfusion of mammary glands during the estrous cycle and should be considered when evaluating pathological changes of mammary glands.

Abstract 1167: A syngeneic MIND model for triple-negative breast cancer: A novel metastatic mouse model for disease progression and therapeutic studies

Abstract Background and Objective: In the era of targeted therapy mouse models have significantly contributed to our understanding of cancer biology. Insight into the molecular pathways has opened new avenues for cancer therapeutic strategies. Majority of the available mouse models depict a portion of the breast cancer progression cascade to be investigated. Some mimic the tumorigenesis at an early stage, some portray the later stage of metastatic process. Additionally, most of the mouse models lack the ability to depict the functional contribution of immune system during metastatic progression because very often they deal with immune-compromised mice. Hence a mouse model that can represent all the stages of breast cancer tumorigenesis and metastasis in native microenvironment in presence of immunity is exceptionally essential. This notion gave us an idea to develop a syngeneic mice model that will epitomize all the breast cancer progression stages and in very short time. Methods: A modified mouse mammary intraductal (MIND) method was adopted for this study. MVT-1 and 4T1 cells were injected into cleaved nipples of 4th inguinal mammary glands of FVB/N and BALB/c wild-type female mice, respectively. The concentration of cells was 10,000 cells/µL. The final volume did not exceed 5 µL per injection per gland. Tissues were harvested at required time points. Histopathology was confirmed by haematoxylin-eosin staining and was further confirmed by immunohistochemical markers for cell proliferation, epithelial-to-mesenchymal transition (EMT), invasion, intravasation, extravasation and metastasis. Results and Conclusions: Primary tumor had been established by the end of first week of injection and was confirmed by histopathology and whole mount analysis of 4th inguinal mammary gland. During second week after cell inoculation, cells had gone through EMT and had prepared and started invasion. Invasion was followed by intravasation and metastasis. Microscopic metastatic patches in the lungs were observed during third week and visible patches were observed during fourth week after injection. The main advantage of this model is short time span. Our model becomes more relevant as the origin of primary tumor and metastasis takes place in same animal, closely resembling biologic progression of breast cancer with the ability to depict the functional contribution of immune system during metastatic progression. A syngeneic mice model like ours can recapitulate the successive stages of breast cancer tumor progression and metastasis and could give the entire picture of metastatic process. We believe that our syngeneic mouse model will facilitate “drug-hunters” and basic science researchers towards developing improved breast cancer treatment. Citation Format: Arnab Ghosh, Sandipto Sarkar, Fariba Behbod, Snigdha Banerjee, Ossama W. Tawfik, Sushanta K. Banerjee. A syngeneic MIND model for triple-negative breast cancer: A novel metastatic mouse model for disease progression and therapeutic studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1167.

Clinicopathological Diversity of Canine Mammary Gland Tumors in Sri Lanka: A One-Year Survey on Cases Presented to Two Veterinary Practices

Mammary gland tumors (MGTs) are one of the most common neoplasms among dogs in Sri Lanka. However, the clinicopathological diversity of MGTs in Sri Lanka is largely unknown, impeding accurate diagnosis and effective treatment of the disease. The present study investigated the clinicopathological features of MGTs in 74 dogs presented to two veterinary practices in Sri Lanka treated surgically, over a one-year period. Information regarding the patient signalment, clinical presentation, and reproductive history were collected, and each neoplasm was examined histologically. Forty-one (54.4%) dogs were primarily presented for mammary neoplasia, while a MGT was an incidental finding in 33 (44.6%) dogs. The majority of tumors were histologically malignant (n = 65, 87.8%), and 18 malignant tumor sub-types were identified. A significantly higher proportion of malignant tumors were large (>3 cm diameter) and observed in inguinal mammary glands. Nulliparous (n = 42, 55.3%) dogs predominated in the group, and the mean age of MGT diagnosis was 8.0 ± 2.41 years. The present study identified tumor location and size to be predictive of malignancy. A high histological diversity of MGTs was observed. Overall, the present findings emphasize the necessity of improving awareness of MGTs among Sri Lankan clinicians as well as dog owners.

Management of stage III benign mammary gland tumor in a 10-year-old female dog

A 10-year-old female German shepherd dog was presented with a large pendulous mass which was located in the area of the right inguinal mammary gland extending from M5–M2 with no marked lymphadenomegaly. The mass has progressively increased in size without regression over a period of 1 year. Radiography revealed a radiodense mass of tissue with no apparent metastasis to regional lymph nodes, no pulmonary metastases, and no abdominal viscera metastases. The tumor was staged as T3N1M0 after diagnostic clinical and radiological examinations based on WHO standards for tumor stage. Unilateral radical mastectomy with total mammary gland extirpation was performed and all glands from M5 to M1 on the right side were removed. The extirpated mass was 24 × 8 cm in size, weighed 2.25 kg, and was very firm. The tumor was lobular and was surrounded with thick band of fibrous capsule. Histology revealed numerous chondroblasts in the lacunae with moderate basophilic cytoplasm. These cells were monomorphic and pleomorphic (> 75% pleomorphic). There was anisocytosis and anisokaryosis. A good short-term clinical outcome was observed after surgical treatment and chemotherapy with tamoxifen and prednisolone for 21 days. Following clinical examinations, no pulmonary metastasis or recurrence of tumoral tissues was observed during 1-year post-surgery. Also, because the pathology of mammary gland tumors in dogs is similar to that of humans, it is strongly advocated that dogs are considered as natural animal model of human breast cancer research especially for testing new drugs and development of prophylactic and therapeutic measures.