Cytology of a seminoma in a koi (Cyprinus carpio): a rapid diagnostic tool.

Koi(Cyprinus carpio) is an ornamental variety of common carp frequently kept as pets. Given their long lifespan, neoplasia, albeit uncommon, may occur in these animals, and only a few studies have faced their cytological diagnosis. In the present case, a koi carp was referred to the clinicians due to coelomic swelling. The carp underwent surgery, which revealed an enlargement of both testes. Testicular samples were cytologically and histologically examined. The lesion was diagnosed as a seminoma since it was composed of round, large, atypical, and often multinucleated cells with round central nuclei and moderate cytoplasm. These tumors had the same appearance as seminomas in mammals and should be considered among differential diagnoses when coelomic swelling occurs in koi carp. Seminomas in koi carp are diagnosed histologically, but cytology, a rapid and cheap exam executable in all veterinary clinical facilities, could be a relevant preliminary diagnostic tool that may influence the entire diagnostic process.

Tumor-associated macrophages and tumor-infiltrating lymphocytes in canine cutaneous and subcutaneous mast cell tumors.

Cutaneous and subcutaneous mast cell tumors (MCTs) are common canine neoplasms characterized by variable biological behavior. Tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) can be effective prognostic markers in numerous human neoplasms and are increasingly investigated in dogs. The aim of this study was to characterize immune cells in canine MCTs and their relationship with histological location (cutaneous, subcutaneous) and histologic nodal metastatic status (HN0-3). Thirty-eight MCTs (26 cutaneous, 12 subcutaneous) from 33 dogs with known sentinel lymph node (SLN) metastatic status were immunolabeled for Iba1 (macrophages), CD20 (B cells), CD3 (T cells), and Foxp3 (regulatory T cells). Semiquantitative scoring of interstitial and perivascular CD3+, CD20+, and Foxp3+ cells and morphological evaluation of Iba1+ cells were performed. For each marker, the percent immunopositive area was evaluated by image analysis. All MCTs were diffusely infiltrated by Iba1+ cells and variably infiltrated by CD20+, CD3+, and rare Foxp3+ cells. Stellate/spindle Iba1+ cells were associated with HN2 and HN3 SLNs. Perivascular Foxp3+ cells, CD3+ cells, and percent CD3+ areas were increased in subcutaneous MCTs. Interstitial CD3+ cells were increased in cutaneous MCTs with HN0 SLNs. No differences in CD20+ cells were identified between cutaneous and subcutaneous MCTs and among SLN classes. MCTs were markedly infiltrated by TAMs and variably infiltrated by TILs. Stellate/spindle morphology of TAMs associated with HN2 and HN3 SLNs is suggestive of a pro-tumoral (M2) phenotype. Cutaneous and subcutaneous MCTs have different tumor-immune microenvironments, and T-cell infiltration might contribute to prevention of nodal metastatic spread of cutaneous MCTs.

Weishaar's classification system for nodal metastasis in sentinel lymph nodes: Clinical outcome in 94 dogs with mast cell tumor.

BACKGROUND: The therapeutic role and prognostic relevance of lymphadenectomy in mast cell tumor (MCT) has historically been evaluated on regional rather than sentinel lymph nodes. HYPOTHESIS/OBJECTIVES: To update information about the association of histological nodal (HN) classes with clinical outcome in dogs with MCT after tumor excision and extirpation of normal-sized sentinel nodes (SLN) guided by radiopharmaceutical. ANIMALS: Ninety-four dogs with histologically-confirmed treatment-naïve MCT (71 cutaneous, 22 subcutaneous and 1 conjunctival MCT) were included if without: distant metastases, lymphadenomegaly, concurrent mixed cutaneous, and subcutaneous MCT. METHODS: This was a monoistitutional cohort study. Tumors characteristics were retrieved and SLNs were classified according to Weishaar's system. Incidence of MCT-related events (local, nodal, distant relapse), de novo MCT or other tumors and death (MCT-related and non-MCT-related), were recorded. Incidence curves were compared among the HN classes. RESULTS: Twenty-seven dogs had HN0, 19 HN1, 37 HN2, and 11 HN3 SLN. Thirteen (2 HN0, 4 HN2, and 7 HN3) received adjuvant chemotherapies. Kiupel high grade, increasing number of SLN and lymphocentrums were associated with higher HN classes. Five dogs died for MCT-related causes: 1 low-grade (HN0) and 1 subcutaneous (HN3) had a local relapse, 2 high-grade had distant relapse (HN3-HN0) and 1 dog developed disease progression from a de novo subcutaneous MCT. No nodal relapse was registered. Fourteen dogs developed de novo MCTs. CONCLUSION/DISCUSSION: Low grade/low-risk MCT with nonpalpable and normal sized SLN have a favorable outcome independently from the HN. Result should be considered strictly related to the successful SLN detection guided pre- and intraoperative by radiopharmaceutical markers.

Canine urothelial carcinoma: expression of Periostin in spontaneous canine urothelial carcinoma and its correlation with histological features.

The tumor microenvironment is considered one of the main players in cancer development and progression and may influence the behavior of cancer cells. Periostin (POSTN) is an extracellular matrix protein, and its main functions are induction of fibrillogenesis, fibroblastic cell proliferation and migration, enhancing regeneration in normal tissue, and promoting metastasis in case of neoplasia. POSTN has already been studied in humans in several normal tissues, inflammatory processes, and neoplasms, revealing an important role in tumor progression in various types of cancer, such as colon, lung, head and neck, breast, ovarian, and prostate. In these latter, high levels of POSTN are usually associated with a more aggressive tumor behavior, tumor advanced stages, and poor prognosis, while in human bladder urothelial carcinoma (BUC), unlike in most tumors, POSTN expression seems to be downregulated. The expression of this marker has been poorly investigated in veterinary medicine; thus, this study aimed to immunohistochemically investigate the presence and the intensity of POSTN expression in canine BUCs and to determine a possible relationship between POSTN expression and histopathological features such as mitotic count and muscular and vascular invasions. For the present retrospective study, archived samples from 45 canine BUCs and 6 non-neoplastic canine bladders were considered for histological evaluation and immunohistochemical examination for the expression of POSTN. POSTN expression was semi-quantitatively assessed considering both the percentage of the neoplastic stroma positive for POSTN and the intensity of the immunohistochemical labeling. Histologically, 38 out of 45 tumors were papillary and 7 out of 45 were non-papillary. All tumors were infiltrating, being that 21 were muscle-invasive, and a significant correlation between this feature and vascular invasion emerged (P = 0.0001). In normal bladder tissue, as reported in humans, a thick and strongly positive belt of POSTN was visible, and in canine BUCs, stating that the expression is comparable with human benign as well as malignant bladder tissue, a general decrease in POSTN expression was observed except for a strongly labeled ring of POSTN observed around some neoplastic nodules infiltrating the muscle layer. Moreover, POSTN expression and mitotic count were significatively inversely correlated (P = 0.0015). The fact that POSTN protein is less expressed in urothelial carcinomas than in the normal bladder supports what was reported in human BUCs and, together with the negative correlation between mitotic count and protein expression that emerged in the present retrospective study, encourages further prospective follow-up studies to verify the possible role of POSTN in canine BUCs as a prognostic marker, and also as a possible target for the development of future anticancer therapies.

Study on the expression of testin in the testes of dogs.

Introduction: Testin is a protein involved in cell mobility, adhesion and colony formation. In rats, testin presence has been reported in the testes, and its possible role in spermatogenesis has been suggested. Studies in humans also suggest a possible role of testin as a cancer suppressor protein. In the dog, which represents both an important pet species and a good animal model for studying biological and pathological testicular processes, the presence of testin has never been reported. Material and Methods: In the present study, the expression of testin in foetal, prepubertal, adult and aged canine testes was investigated. Testes from 5 adult and 3 aged dogs, from 2 one-month-old puppies and from 2 foetuses miscarried at the end of pregnancy were immunohistochemically examined with a commercial antibody against testin. Results: Testin was intensely expressed in Sertoli cells in every testis examined. Spermatids were also positive for testin in mature dogs and in the testicular areas of the aged ones which were not atrophic. Weak expression of testin was also detected in all testes examined. Conclusion: The present study, the first demonstrating the presence of testin in canine testes, provides the basis for further dog-human comparative research and for studies on the role of this protein in canine physiology, reproduction and testicular pathologies.

Evaluation of Surgical Aid of Methylene Blue in Addition to Intraoperative Gamma Probe for Sentinel Lymph Node Extirpation in 116 Canine Mast Cell Tumors (2017-2022).

Methylene Blue (MB) is combined with radiopharmaceutical for intraoperative sentinel lymph node (SLN) mapping, but its role during SLN extirpation has not been investigated yet in veterinary medicine. The aim of this study was to assess whether MB increased surgical detection of SLN beyond the use of intraoperative gamma-probe (IGP) alone in clinically node-negative dogs with mast cell tumors (MCTs) following the detection of sentinel lymphocentrums (SLCs) via preoperative planar lymphoscintigraphy. Dogs enrolled underwent MCT excision and SLC exploration guided by both MB and IGP. Data recorded for each SLN were staining (blue/non-blue), radioactivity (hot/non-hot), and histopathological status (HN0-1 vs. HN2-3). A total of 103 dogs bearing 80 cutaneous, 35 subcutaneous, and 1 mucocutaneous MCTs were included; 140 SLCs were explored, for a total of 196 SLNs removed. Associating MB with IGP raised the SLNs detection rate from 90% to 95%. A total of 44% of SLNs were metastatic: 86% were blue/hot, 7% were only blue, 5% were only hot, and 2% were non-blue/non-hot. All HN3 SLNs were hot. Combining MB with IGP can increase the rate of SLN detection in dogs with MCTs; nonetheless, all lymph nodes identified during dissection should be removed, as they might be unstained but metastatic.

Cytological Quantification of Nodal Mast Cells in Dogs Affected by Non-Neoplastic Condition and Mast Cell Tumor Using Different Sample Preparation Techniques: An Explorative Study.

Cytological evaluation of lymph nodes (LN) in canine cutaneous mast cell tumors (MCT) has a key role in MCT staging. However, cytological discrimination between metastatic and reactive LNs is debated and diagnostic criteria inconsistent. The aim of this study was to retrospectively quantify nodal mast cells (MCs) in non-oncological (NOD) and MCT-bearing dogs (MCTBD), using different sample preparation techniques, to evaluate the significance of the MCT number. Cytological specimens from NOD-LNs (10 fine-needle aspirates-FNAs) and MCTBD-LNs (10 FNAs, 10 scrapings, 10 touch imprints) were evaluated. MCTBD-LNs were grouped in: non-metastatic, possibly-metastatic, and metastatic based on current literature criteria. MCs were counted in 4, 8, and 20 high-power-fields, and over 500, 1000, and 2000 total cells. MCs were significantly more numerous in MCTBD-LNs than in NOD-LNs and in "metastatic" samples than in "non-metastatic". There was no significant difference between "metastatic" and "possibly metastatic" samples. Sample preparation techniques did not influence these results. A negative correlation between MCs number and sample cellularity was observed. Results were confirmed regardless of the counting method applied. MCs counting per se cannot distinguish possibly metastatic and metastatic cytological samples. Sample preparation technique and the counting method applied seem to have no influence on cytological quantification of nodal MCs in MCTBDs.

First report of primary testicular leiomyosarcoma in two dogs.

BACKGROUND: Testicular tumours are common in dogs and, among them, interstitial cell tumours, seminomas and sustentacular cell tumours are the most reported. Mesenchymal testicular tumours are rarely reported in humans as in veterinary medicine where only three cases of sarcomas (leiomyomas and leomyosarcomas) have been described in two stallions and in a ram. CASE PRESENTATION: The present cases regarded a 12-year-old mixed-breed dog and a 10-year-old American Staffordshire Terrier that underwent bilateral orchiectomy. Formalin fixed testes were referred for histopathological diagnosis. At gross examination, in one of the testes of both dogs, a white, firm and variably cystic testicular mass, effacing and replacing the testicular parenchyma was detected. Samples were collected from both neoplastic and contralateral testes, routinely processed for histology and serial sections were also examined immunohistochemically with primary antibodies against cytokeratins, vimentin, Von Willebrand factor, inhibin-α, α-smooth muscle actin, smooth muscle myosin and desmin. Histopathological features as well as the immunohistochemical results, positive for vimentin, actin, myosin and desmin, confirmed the mesenchymal origin and the myoid phenotype of both testicular tumours supporting the diagnoses of leiomyosarcoma. CONCLUSIONS: To the authors knowledge these are the first cases of primary testicular sarcoma reported in the canine species. However, even rare, these tumours deserve to be considered in routine diagnosis when a testicular spindle cell tumour is observed. The immunohistochemical panel applied was useful to distinguish the present tumours from undifferentiated Sertoli cell tumours confirming the diagnosis of leiomyosarcoma.

MicroRNA as epigenetic regulators of canine cryptorchidism.

Cryptorchidism, the failed descent of one or both testes into the scrotum, is a common developmental disorder in male dogs. Cryptorchidism may affect canine fertility, reducing the quality of the semen, and may promote spermatic cord torsion and onset of neoplasia. MicroRNAs (miRNAs) are epigenetic regulators of gene expression and their dysregulation is associated with disorders of spermatogenesis and testis neoplasia. The present study aimed at investigating the expression of miRNAs in formalin-fixed, paraffin-embedded (FFPE) canine retained testes and testes affected by seminoma, and at integrating miRNAs to their target genes. Forty testicular FFPE specimens from 30 dogs were included - 10 scrotal and 10 contralateral retained from 10 unilateral cryptorchid dogs; 10 tumoral testes affected by seminoma from non-cryptorchid dogs; 10 scrotal normal testes from non-cryptorchid dogs included as the control. The expression level of three miRNAs, namely miR-302c-3p, miR-302a-3p, and miR-371-3p, associated with testicular disorders, were quantified using RT-qPCR. The comparative analysis demonstrated that the level of miR-302a-3p and miR-371a-3p were quantifiable exclusively in control testes. The expression level of miR-302c-3p was higher in the control than in the other groups; its expression decreased in retained testes compared to scrotal testes and testes with seminoma. Gene Ontology analysis pointed out that these miRNAs may be involved in the modulation of estrogen and thyroid hormone signaling pathways. In conclusion, this study demonstrated that miRNAs are dysregulated in canine cryptorchid and seminoma-affected testes compared to control tissues, confirming the pivotal role of miRNAs in cryptorchidism.

An Unusual Case of Collision Testicular Tumor in a Female DSD Dog.

Collision tumors (CT) consist of two independent neoplasms with distinct neoplastic populations. Disorders of sexual development (DSDs) are characterized by atypical sexual development leading to various abnormalities of the genital tract. Sex reversal (SR) syndromes are a type of DSD characterized by a discrepancy between chromosomal sex and gonadal development (testes/ovaries) and the presence or the absence of the SRY gene. A phenotypically female 8-year-old Jack Russell terrier dog was referred due to anomalous vaginal discharge and non-pruritic cutaneous bilateral symmetrical alopecia on the flanks. During abdominal palpation, a voluminous mass was detected in the left quadrant area, later confirmed by ultrasound. The owner decided to proceed with euthanasia and necropsy. In the abdominal cavity, the left gonad was increased in size, the right one and the uterus were decreased, and the vagina and vulva appeared to be thickened. Histologically, both gonads were revealed to be testes: the left one was affected by a double neoplastic component (sustentacular tumor and interstitial cell tumor), whereas the right gonad showed coarctated seminiferous tubules. PCR amplification of the genes SRY and AMELX revealed the absence of the MSY region of the Y chromosome. To the authors' knowledge, this is the first report describing a case of a testicular collision tumor in a DSD SRY-negative dog.

Endocrine-Disrupting Chemicals and Their Effects in Pet Dogs and Cats: An Overview.

Over the past few decades, several pollutants classified as environmental endocrine-disrupting chemicals (EDCs) have become a matter of significant public health concern. Companion animals play a major role in human society, and pet ownership is substantially increasing worldwide. These intimate human-pet relationships imply sharing much of the same environment, thus including exposure to similar levels of EDCs in daily routine. Here, we review the current knowledge on the sources and routes of exposure to EDCs in domestic indoor and outdoor environments and discuss whether endocrine disruption is a health concern in pets. We summarize the phenomenon of endocrine disruption, providing examples of EDCs with a known impact on dog and cat health. Then, we propose an overview of the literature on the adverse effects of EDCs in domestic pets, with a special focus on the health of reproductive and thyroid systems. Finally, we explore the potential role of companion animals as unintentional sentinels of environmental exposure to EDCs and the implications for public health risk assessment in a "shared risk" scenario. Overall, this review supports the need for an integrated approach considering humans, animals, and the environment as a whole for a comprehensive assessment of the impact of EDCs on human and animal health.

Lymph node metastasis in feline cutaneous low-grade mast cell tumours.

OBJECTIVES: This retrospective study aimed to determine the incidence of nodal metastatic disease in cats affected by low-grade cutaneous mast cell tumours (MCTs) in our study population. METHODS: The clinical records of two centres were retrospectively searched for cats with cutaneous MCTs that had undergone lymphadenectomy of enlarged and non-enlarged lymph nodes. All primary tumours were histologically reviewed by two experienced pathologists and graded as high- or low-grade based on the grading system for feline cutaneous MCT. We graded the lymph nodes based on the grading scheme used for canine MCTs and considered HN2 and HN3 nodes to be metastatic. The number of patients with nodal metastasis was calculated. RESULTS: We identified 17 cats with cutaneous MCT resection and concurrent lymphadenectomy. All 21 MCTs were graded as low grade and 30 nodes were removed, with 12 being considered early or overtly metastatic (HN2 or HN3, respectively). Based on nodal status, 10/17 (59%) cats were affected by nodal metastasis in our population. CONCLUSIONS AND RELEVANCE: In contrast to previous reports, high percentage of cats with cutaneous MCTs in which lymphadenectomy was performed were presented with metastatic lymph nodes. The clinical relevance of this finding and a potential benefit of lymphadenectomy must be determined in future studies.

Salivary miR-21 is a potential biomarker for canine mast cell tumors.

MicroRNAs (miRNAs) are a class of noncoding RNA molecules playing a crucial role in tumor modulation targeting mRNA. This study aimed to validate the diagnostic potential of a panel of 3 miRNAs previously identified in canine mast cell tumors (MCTs), miR-21, miR-379, and miR-885, as markers of lymph node involvement in terms of histological absence (nonmetastatic: HN0; premetastatic: HN1) and presence (early-metastatic: HN2; overt-metastatic: HN3) of metastasis, in the saliva of mast cell tumor (MCT)-affected dogs by quantitative polymerase chain reaction (PCR). Forty-seven saliva samples were analyzed: 36 from MCT-affected dogs (12 subcutaneous [3 HN0-1 and 9 HN2-3] and 24 cutaneous [9 HN0-1 and 15 HN2-3-MCT]) and 11 from healthy dogs. MCT-group effects were investigated using analysis of variance (ANOVA). The origin of the tumor affected the expression of salivary miR-21 (P = .011) with an increase in cases with subcutaneous MCTs compared with the healthy group (P = .0005) and those with cutaneous MCTs (P = .004). Salivary miR-21 was higher in the HN2-3 class compared with the healthy group (P = .004). Salivary miR-885 was not affected by the presence of MCT, while miR-379 was not detected in saliva. The diagnostic potential of salivary miR-21 in discriminating MCT-affected dogs from the healthy group (AUC = 0.8917), cutaneous from subcutaneous (AUC = 0.8111), and subcutaneous HN0-1 (AUC = 0.7250) and HN2-3 (AUC = 0.9750) classes from healthy samples was demonstrated by receiver operating characteristic curve analysis. Overall, salivary miR-21 was identified as a promising tool, representing a novel approach to detecting MCT-associated epigenetic alterations in a minimally invasive manner.

Surgical complications following sentinel lymph node biopsy guided by γ-probe and methylene blue in 113 tumour-bearing dogs.

Sentinel lymph node biopsy (SLNB) is an accepted veterinary surgical procedure given the impact of early detection of nodal metastases on staging of several canine malignancies. This study aims at reporting the incidence and risk factors for surgical complications of SLNB in tumour-bearing dogs. A total of 113 client-owned dogs that underwent tumour excision and SLNB guided by γ-probing and blue dye were retrospectively enrolled. Recorded variables included: signalment, location and number of extirpated lymphocenters and nodes, time for SLNB, histopathological status of excised nodes. Incidence of SLNB complications was calculated. They were classified as minor and major based on severity and required treatment, and as short-term (0-30 days) and long-term (31-90 days). Univariate analysis with generalized linear model with binomial error estimated the association between variables and incidence of SLNB complications. Significance was set at 5%. Median overall time for SLNB was 25 min. Surgeons excised one node in 38% of dogs and multiple nodes in 62% of cases, belonging to one (62%) or multiple (38%) lymphocenters. Metastases were detected in 45% of nodes. No intraoperative complications occurred. The overall incidence of postoperative complications of SLNB was 21,24%, the majority of which (91.67%) were minor. Only increasing dogs' weight was associated with an increased incidence of SLNB complications (p = .00976). Sentinel lymphadenectomy was associated with a relatively low incidence of complications, most of which were self-limiting. The low morbidity and previously reported impact on staging of SLNB justify its implementation to collect data for prognostic studies.

Sentinel Lymph Node Mapping and Biopsy in Cats with Solid Malignancies: An Explorative Study.

There is increasing evidence on the utility of sentinel lymph node (SLN) biopsy (SLNB) for the staging of dogs with various malignancies; however, comparable information is missing in cats. This multi-institutional study aims at reporting the feasibility and detection rate of SLNB guided by lymphoscintigraphy and the blue dye or near-infrared fluorescent lymphography (NIRF-L) in cats with solid tumors. In total, 12 cats presented with 14 solid malignancies that underwent curative-intent surgical excision of the primary tumor and SLNB were retrospectively enrolled. The mapping technique used, location and number of SLN, correspondence with the regional lymph node (RLN), and histological status of the SLN were retrieved. The detection rate and complications of SLNB were also recorded. NIRF-L was performed in 64.3% of tumors and lymphoscintigraphy in 35.7%. The detection rate was 100% for both techniques. The SLN did not correspond (fully or partially) to the RLN in 71.4% of cases, with multiple SLN being excised in 9/14 tumors. No complications related to SLNB were recorded. At histopathology, metastases were identified in 41.7% of cats, all with mast cell tumors (MCT). SLNB guided by NIRF-L or lymphoscintigraphy is feasible and safe in cats with solid tumors and should be suggested for correct tumor staging in cats, especially with MCT.

Caveolin-1, GATA-3, and Ki67 expressions and their correlation with pathological findings in canine bladder urothelial carcinoma.

The bladder urothelial carcinoma (UC) represents ~2% of malignant neoplasms in dogs and is a therapeutic challenge in veterinary medicine. Although it is considered the most common bladder cancer in dogs, few previous studies have investigated different markers that correlate with clinical and pathological parameters. Therefore, this study aimed to evaluate Caveolin-1, GATA-3, and Ki67 immunostaining in canine UC samples to evaluate their correlations with histopathological variables. Thirty tumor samples were obtained, and Caveolin-1, GATA-3, and Ki67 expression was assessed by immunohistochemistry and associated with pathological factors by univariate and multivariate analyses. Among the histopathological findings, lymphatic invasion was identified in 53.33% of the tumors, and the mean mitotic count (MC) was 31.82 ± 26.26. Caveolin-1 showed mild-to-high cytoplasmic expression in neoplastic cells, whereas GATA-3 showed mild-to-high nuclear expression. The Ki67 expression revealed a mean of 24.14 ± 16.88% positive cells. In the univariate analysis, no association was found between each marker and the pathological findings. On the other hand, in multivariate analysis, we identified a positive correlation between GATA-3 and MC and a negative correlation between Caveolin-1 and MC. Moreover, lymphatic invasion was positively correlated with histological type and grade, and negatively correlated with MC. In addition, the histological type was positively correlated with the histological grade. Overall, our results indicate that Caveolin-1 and GATA-3 expression could be promising markers for bladder UC aggressiveness.

Sentinel Lymph Node Biopsy Is Feasible in Dogs with Scars from Prior Local Excision of Solid Malignancies.

Sentinel lymph node (SLN) biopsy is a well-established staging tool in canine oncology. This study aims to explore the feasibility of SLN biopsy in dogs with scars from prior excised solid malignancies that were referred for further tumor staging and/or adjuvant treatment options. Mapping was either performed using radiopharmaceutical, methylene blue, and/or near-infrared fluorescent (NIRF) imaging. Thirty-three dogs with 34 scars from prior excision of the mast cell tumor (MCT) (n = 29), soft tissue sarcoma (n = 2), oral melanoma (n = 1), subungual melanoma (n = 1), and mammary adenocarcinoma (n = 1) were retrospectively enrolled. Primary treatment consisted of curative intent/wide tumor excisions in 50.0% of dogs and marginal excision in the remaining 50.0%. The median time between tumor excision and SLN biopsy was 50 days (range 17-110 days). The procedure was successful in 31/34 scars, translating to a detection rate of 91.2%. The SLN did not correspond to the regional lymph node in 19/31 scars (61.3%). SLN metastases were histologically identified in 13/31 (41.9%) dogs, all of them affected by MCT. Based on our results, SLN biopsy using lymphoscintigraphy/methylene blue and/or NIRF is feasible in dogs presenting with scars from the prior surgical excision of solid tumors, and should be suggested for accurate nodal staging.

Ovarian Neuroglial Choristoma in a Bitch.

Neuroglial choristomas are rare malformations consisting of heterotopic mature neural tissue at a site isolated from the brain or spinal cord. In human medicine, neuroglial choristomas are predominantly reported in the head and in the neck, except for one recent case reported in a foot of a child. In domestic animals, neuroglial choristomas are exceedingly rare, reported only in the retina of a dog, in the pharynx and in the skin of two kittens, and within the oropharynx of a harbor seal. A three-year-old intact female Jack Russell Terrier presented for elective ovariectomy exhibited a cystic lesion 2 cm in diameter expanding in the right ovary. Histological examination of the lesion revealed a mass composed of well-organized neuroglial tissue. Immunohistochemistry with primary antibodies against GFAP, NSE, and IBA-1 confirmed the neuroglial origin of the mass. At the time of this writing, 7 years after ovariectomy, the dog was clinically normal. Together with a recent case described in the foot of a child, this case confirms that neuroglial choristoma may also be found far from the skull or spine, supporting the hypothesis that they may arise from an early embryological migration defect.

Tracheal Hemangioma Causing Lung Emphysema and Pneumopericardium in a Rabbit-A Case Report.

A pet rabbit (female, 8 years old, and mixed breed) with symptoms of dyspnea, apathy, and weight loss was treated for an acute respiratory infection. Due to the lack of improvement, it was referred to the Imaging Diagnostics Laboratory of the Department and Clinic of Surgery for a computer tomography scan of the thoracic cavity. The examination revealed the presence of air in the pericardial sac, a pneumopericardium, along with pulmonary emphysema. A few minutes after the examination, the rabbit developed circulatory and respiratory failure and died. Necropsy confirmed the presence of a pneumopericardium and pulmonary emphysema, and revealed, in the tracheal lumen, the presence of a tumor histologically consistent with hemangioma. A spontaneous pneumopericardium occurs when air from the respiratory system moves into the pericardial sac. This is the first case of the simultaneous occurrence of tracheal hemangioma and a pneumopericardium in a rabbit.

Reproducibility and Feasibility of Classification and National Guidelines for Histological Diagnosis of Canine Mammary Gland Tumours: A Multi-Institutional Ring Study.

Histological diagnosis of Canine Mammary Tumours (CMTs) provides the basis for proper treatment and follow-up. Nowadays, its accuracy is poorly understood and variable interpretation of histological criteria leads to a lack of standardisation and impossibility to compare studies. This study aimed to quantify the reproducibility of histological diagnosis and grading in CMTs. A blinded ring test on 36 CMTs was performed by 15 veterinary pathologists with different levels of education, after discussion of critical points on the Davis-Thompson Foundation Classification and providing consensus guidelines. Kappa statistics were used to compare the interobserver variability. The overall concordance rate of diagnostic interpretations of WP on identification of hyperplasia-dysplasia/benign/malignant lesions showed a substantial agreement (average k ranging from 0.66 to 0.82, with a k-combined of 0.76). Instead, outcomes on ICD-O-3.2 morphological code /diagnosis of histotype had only a moderate agreement (average k ranging from 0.44 and 0.64, with a k-combined of 0.54). The results demonstrated that standardised classification and consensus guidelines can produce moderate to substantial agreement; however, further efforts are needed to increase this agreement in distinguishing benign versus malignant lesions and in histological grading.