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Cryptorchidism is a common disorder in the canine population with some aspects still unclear. Although the bilateral condition is known to lead to fertility problems and predisposition to testicular cancer, the neoplastic risk for scrotal testis in unilateral cryptorchid dog is controversial. Therefore, the therapeutic approach to the canine unilateral cryptorchid is arbitrary so far. This study aimed to investigate precancerous testicular lesions, such as immaturity and atrophy, and compare them in scrotal and undescended testes using an in-depth diagnostic analysis based on immunophenotypic patterns. With this purpose, 26 adult male dogs of different ages and breeds, affected by unilateral or bilateral cryptorchidism were enrolled. After surgical removal, testes were examined immunohistochemically to assess their positivity for specific markers of the canine foetal/neonatal period, that is vimentin (VIM), cytokeratin (CK), desmin (DES), inhibin-α (INH), and anti-Müllerian hormone (AMH) in Sertoli cells, and placental alkaline phosphatase (PLAP) in germ cells. Except for the ubiquitous VIM, all the markers were more expressed in neoplastic gonads compared to healthy ones (P 0.05). Similarly, testes detected with Sertoli cell-only tubules as well as with Sertoli cells hyperplasia showed higher expression than gonads without such alterations for CK, DES, AMH and PLAP, and for CK and DES, respectively (P 0.05). The same trend was observed in undescended respect to scrotal testes even though their positivity was significant only for DES, INH and AMH (P 0.05). Immunohistochemical positivity found in scrotal testes of unilateral cryptorchid dogs, even in absence of detectable anatomical abnormalities, was suggestive of precancerous lesions. Despite the limited sample size, this study could help to clarify the predisposition to neoplastic development in normally descended testes. These markers expression in adult life could allow identifying the early stages of the testicular carcinogenesis process besides suggesting a precautionary bilateral surgical approach in unilateral cryptorchid dogs.

Canine mammary tumours represent a hard-prognostic task for veterinary clinicians. TNM staging and grading systems refer to a single tumour. Significant limits come to light when these systems are applied to multiple mammary tumours due to the arbitrary criterion in determining which single tumour is representative of the patient's prognosis. This study explored some clinical features of 50 dogs affected by at least one malignant mammary tumour. Clinical features and staging, together with histological classification and grading, have been related to disease-free survival (DFS) with the purpose to evaluate their impact on prognosis. The prognosis was worse in 10-11-year-old dogs (P 0.05), in dogs affected by complex carcinoma (P 0.05), and in patients assigned to Peña grade I (P 0.05). The bodyweight was not linearly related to DFS (P 0.01), and patients with a low number of neoformations (n ≤ 2) showed a better prognosis than dogs with 3-5 tumours (P 0.05). Both the average and the total size of malignant tumours were related to DFS (P 0.05). Dogs assigned with stage I had the best DFS (P 0.05). In conclusion, the Peña grade I alone would not seem to guarantee a favourable prognosis when applied to mammary tumours in dogs affected by multiple simultaneous presentations. Different characteristics, besides tumour grading, such as tumour immunophenotype and expression of hormonal receptors, could in the future, contribute to elucidate the clinical behaviour of multiple canine mammary tumours.

Prostatic leiomyosarcoma is an uncommon tumor encountered in male dogs, with only 2 cases reported in the veterinary literature with no follow‐up described. A 12‐year‐old male intact German Wirehaired Pointer presented for evaluation of straining to defecate and urinate. Whole body computed tomography (CT) examination identified a spherical multicavitary expansile mass arising from the prostate gland and severely obliterating the pelvic canal. Partial subcapsular prostatectomy was performed, and histological and immunohistochemical results were consistent with prostatic leiomyosarcoma. Metronomic cyclophosphamide and nonsteroidal anti‐inflammatory drugs were administered as adjuvant chemotherapy. Follow‐up CT 10 months later indicated no signs of recurrence or metastasis. To the best of our knowledge, this patient represents the first report of successful multidisciplinary treatment consisting of partial subcapsular prostatectomy and adjuvant chemotherapy for prostatic leiomyosarcoma in a dog. After 15 months of follow‐up, the patient remained recurrence‐free without metastasis.

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.

A 34-day-old, male, white-bellied caique (Pionites leucogaster) was presented for a complaint of bilateral buphthalmos. Clinical examination was unremarkable apart from the ophthalmic findings. The ophthalmologic examination was negative for direct, consensual, and dazzle reflexes in both eyes. The intraocular pressure exceeded 40 mm Hg OU. Fluorescein stain demonstrated corneal surface lesions suggestive of exposure keratopathy subsequent to bilateral buphthalmos. Diagnostic imaging tests were conducted to perform ocular biometric measurements and investigate the intraocular structures, including the iridocorneal angle and lens, by means of high-resolution ultrasonography (HRUS). The presence of congenital glaucoma in this young parrot was strongly suspected after clinical and ophthalmological examination and the results of diagnostic imaging. Pharmacological treatment to reduce intraocular pressure was initiated using dorzolamide hydrochloride 2% and timolol maleate 0.5%. A month later, the parrot's eyes did not show any visual improvement, but the intraocular pressure had returned to normal. The parrot was unable to feed itself and died during a feeding procedure. Postmortem examination revealed ab ingestis pneumonia. Both eyes were submitted for histopathology, with severe anterior segment dysplasia and goniodysgenesis found OU. Histological findings added to the clinical presentation, the ophthalmologic examination and the imaging findings, confirmed the presence of congenital glaucoma.

OBJECTIVE: To report the outcomes associated with sentinel lymph nodes (SLN) detection and extirpation guided by radionuclide and methylene blue injections in dogs with cutaneous and subcutaneous mast cell tumors (MCT). STUDY DESIGN: Clinical prospective cohort study. ANIMALS: Thirty client‐owned dogs with MCT amenable to wide‐margin excision, without evidence of distant metastasis and abnormal regional lymph nodes (RLN). METHODS: Technetium‐99 m and methylene blue were injected peritumorally. Dogs underwent preoperative γ‐camera scintigraphy and an intraoperative γ‐probe‐guided SLN extirpation. Outcomes included technical and surgical complications, number of SLN, SLN location respecting the expected RLN, and histopathology results. RESULTS: Sentinel lymph node mapping was applied to 34 MCT in 30 dogs without any complication. Sentinel lymph nodes were not identified in three of 34 tumors, all with previous scar tissue. Sentinel lymph nodes did not correspond to expected RLN in 19 of 30 (63%) tumors. Histological examination confirmed an early or overt metastasis in 32 of 57 (56%) SLN extirpated. CONCLUSION: Sentinel lymph node mapping and biopsy with radionuclide and injection of methylene blue was associated with low morbidity and allowed detection of SLN in dogs with MCT at first presentation without scar tissue. CLINICAL SIGNIFICANCE: Incorporation of SLN mapping and extirpation allows for a personalized staging approach in dogs with MCT. The presence of scar tissue in dogs with recurrent tumors seems to be a limitation for SLN mapping with this technique.

Purpose To evaluate the immediate effects on cornea and conjunctiva of a cryosurgical method based on the application of a dimethyl ether, propane and isobutene solution (DMEPI, Histofreezer® ), and of Liquid Nitrogen (LN2 ; Cry-Ac Cryogun® ). Methods A total of 52 isolated pig eyes were obtained at the slaughterhouse, preserved for less than one hour in Ringer Lactate and divided into four groups. The first group included eyes treated with two applications of DMEPI in the center of the cornea, the second group eyes treated with DMEPI on the third eyelid's conjunctiva, the third group eyes treated with LN2 on the third eyelid's conjunctiva and the fourth group included eyes treated with LN2 on the central cornea. Each cryogen application (0.8 cm area) lasted 40 seconds. Each group included one (untreated) control eye. The eyes were submitted for routine histopathological evaluation. Histological alterations were recorded and scored with a semiquantitative scoring system. Results No tissue alteration was detected on the conjunctiva, in any of the groups. Treated corneas showed mild to moderate cytoplasmic vacuolization of epithelial cells, shrinkage and hypereosinophilia of small groups of basal epithelial cells and stromal cleft formation. Conclusions Soft cryosurgery caused no severe acute histologically detectable damage to cornea and conjunctiva in isolated pig eyes, and no significant difference was observed when LN2 and DMEPI treatments were compared. Further in vivo studies should be performed in order to verify possible delayed effects and the clinical efficacy of DMEPI cryosurgery in specific corneal and/or conjunctival diseases.

The recent literature supports the sentinel lymph node (SLN) biopsy in dogs with MCT due to discrepancy with the regional lymph node and the high percentage of occult metastasis. However, the SLN biopsy includes additional anesthesiologic, diagnostic, and surgical procedures, and additional costs. The study aimed to assess the association between clinicopathological variables and SLN status, determining the identification of dogs at lower risk of SLN metastases. Dogs with integumentary MCT were admitted to the lymphoscintigraphic mapping and subsequent biopsy of SLN. The association between clinicopathological variables of MCT and SLN status was statistically tested, both considering occult and overt metastasis together (HN2-HN3) and overt metastasis (HN3) alone. Fifty low-grade cutaneous MCT and 16 subcutaneous MCT were included. A small to moderate association between integumentary MCT ≥ 3 cm and HN2-HN3 SLN was found. A strong association of integumentary MCT dimension and subcutaneous MCT with HN3 SLN occurred. Dimension of low-grade cutaneous and subcutaneous MCT seems to correlate with SLN status, but additional study should confirm this data before excluding small MCT to the SLN biopsy. On the contrary, the study results induce a solid suggestion for mapping and biopsy of the SLN in MCT &gt, 3 cm and subcutaneous MCT.

Lacrimal gland tumors (LGTs) in dogs and cats are rare neoplasms that can affect either the nictitans (NLG) or the main lacrimal gland (MLG). A consistent classification scheme for canine and feline LGTs is lacking; however, the importance of a classification scheme for LGTs has been emphasized in the human literature, and an update to the World Health Organization (WHO) classification has recently been published. The aim of this study was to investigate the occurrence of different subtypes of canine and feline LGTs in accordance with the human WHO classification system. Epithelial LGTs ( n = 46 tumors; 38 dogs, 8 cats) were reviewed and immunophenotyping for p63, CK14, SMA, calponin, CKAE1/AE3, and CK19 was performed. Consistent with previous literature reports, lacrimal carcinomas outnumbered adenomas in dogs and cats. Based on the WHO classification of human LGTs, the most common subtypes identified in dogs were pleomorphic, ductal, adenoid cystic, and epithelial-myoepithelial carcinoma. In cats, a lower number of subtypes was observed, and adenocarcinoma “not otherwise specified” (NOS) was the most frequent diagnosis. An uncommon case of feline epithelial-myoepithelial carcinoma was also observed. The application of the human WHO-LGT classification scheme to canine and feline tumors increased the diversity of diagnoses and allowed for the identification of numerous subtypes. Further studies to identify possible correlations between pathological subtypes and prognosis are warranted.

Tumour stage is a prognostic indicator for canine malignant head and neck tumours (MHNT). However, consensus is lacking on nodal staging in the absence of clinically apparent nodal disease (cN0 neck). This prospective observational study aims to determine the diagnostic accuracy of radiopharmaceutical and blue dye for sentinel lymph node biopsy (SLNB), to assess the correspondence between sentinel lymph node (SLN) and clinically expected regional lymph node (RLN) and the impact on staging of the procedure in dogs with MHNT and cN0 neck. Twenty-three dogs with MHNT and cN0 neck underwent tumour excision and SLNB guided by preoperative lymphoscintigraphy and intraoperative gamma-probe and blue dye. Diagnostic performances and detection rate were calculated. Correspondence between SLN and RLN, number of nodes excised, histopathological status of the SLN and complications related to the procedure were recorded. The mapping technique identified at least one SLN in 19/23 dogs, with a detection rate of 83%. The SLN did not correspond to the RLN in 52% of dogs. Multiple nodes were removed in 61% of dogs. At histopathology, eight (42%) dogs had SLN+, of which four differed from the RLN. Only minor self-limiting complications occurred in five (22%) dogs. Radiopharmaceutical and blue dye guidance is accurate (sensitivity 88.9%; specificity 100%) for SLNB in dogs with MHNT and cN0 and allowed the extirpation of unpredictable and/or multiple SLN with minimal morbidity. Incorporation of SLNB in the management of MHNT is desirable to correctly stage the cN0 neck, owing the unpredictability of the lymphatic drainage.

Sentinel lymph node (SLN) mapping is the current gold standard for the oncological staging of solid malignancies in humans. This prospective observational study describes the feasibility and the limits of preoperative lymphoscintigraphy for SLN detection in dogs with spontaneous malignancies and the improvements in staging accuracy. Client‐owned dogs with confirmed malignant neoplasia and absence of distant metastasis were prospectively enrolled. Lymphoscintigraphy was performed after the peritumoral injection of Technetium‐99m labeled nanocolloids. Regional dynamic and static images were acquired, with and without masking of the injection site with a lead shield. The dogs were then subjected to surgery for tumor excision and SLN extirpation. Intraoperative SLN detection was performed by combining methylene blue dye and a dedicated gamma probe. Overall, 51 dogs with a total of 60 solid malignant tumors were enrolled. Lymphoscintigraphy identified at least one SLN in 57 of 60 cases (95%). The SLN did not always correspond to the regional lymph node (35/57, 61.4%). The use of a lead shield, masking the injection site, markedly improved the SLN visibility. The median time of SLN appearance was 11.4 ± 9.3 min. No side effects were observed. Preoperative lymphoscintigraphy allows for SLN detection in dogs and can improve staging accuracy by either identifying the SLN in a different lymphosome than clinically expected or discriminating the draining node in uncertain cases. The combined use of preoperative and intraoperative techniques is recommended to increase the SLN detection rate.

Lipid-rich carcinoma is a rare histotype of canine mammary tumors with cytoplasmic vacuolation. In humans, glycogen-rich carcinoma, secretory carcinoma, and myoepithelial neoplasms are included in the differential diagnosis for lipid-rich carcinoma. The aim of the study was to investigate the existence of histotypes other than lipid-rich in canine mammary carcinomas with vacuolated cytoplasm using a diagnostic algorithm based on histopathology, histochemistry, immunohistochemistry, and ultrastructure and to evaluate the molecular phenotype of these neoplasms. Ten mammary carcinomas were collected, histologically reviewed, and subjected to histochemistry (PAS, PAS with diastase, Alcian blue, Sudan III [1 case], and Congo red [1 case]); immunohistochemistry for CK19, CK5/6, CK14, p63, calponin, vimentin, ER, PR, and HER2; and transmission electron microscopy (TEM). Cytokeratin immunolabeling demonstrated the epithelial origin of all tumors. Sudan III and TEM confirmed the diagnosis of lipid-rich carcinoma in 8 tumors (one amyloid-producing). One tumor was reclassified as a glycogen-rich carcinoma based on PAS reactivity that was diastase-labile, and a second tumor was reclassified as a carcinoma-and-malignant myoepithelioma based on the differentiation markers. Lipid-rich carcinomas were basal-like (5/8), null-type (2/8), and luminal A phenotype (1/8). The glycogen-rich carcinoma was basal-like, while the carcinoma-and-malignant myoepithelioma was luminal A. Vacuolated morphology of neoplastic cells in canine mammary carcinoma can indicate either a neoplasm of luminal epithelial origin with cytoplasmic lipid or glycogen, or vacuolated neoplastic suprabasal myoepithelial cells. Glycogen-rich carcinoma is a novel histological type that should be considered in the differential diagnosis for canine mammary carcinomas with vacuolated cytoplasm.

Nano- and microsized extracellular vesicles (EVs) are naturally occurring cargo-bearing packages of regulatory macromolecules, and recent studies are increasingly showing that EVs are responsible for physiological intercellular communication. Nanoparticles encapsulating anti-tumor theranostics represent an attractive "exosome-interfering" strategy for cancer therapy. Methods: Herein, by labeling plasma-derived EVs with indocyanine green (ICG) and following their biodistribution by in vivo and ex vivo imaging, we demonstrate the existence of nanoparticles with a highly selective cancer tropism in the blood of colorectal cancer (CRC) patients but not in that of healthy volunteers. Results: In CRC patient-derived xenograft (PDX) mouse models, we show that transplanted EVs recognize tumors from the cognate nanoparticle-generating individual, suggesting the theranostic potential of autologous EVs encapsulating tumor-interfering molecules. In large canine breeds bearing spontaneous malignant skin and breast tumors, the same autologous EV transplantation protocol shows comparable safety and efficacy profiles. Conclusions: Our data show the existence of an untapped resource of intercellular communication present in the blood of cancer patients, which represents an efficient and highly biocompatible way to deliver molecules directly to the tumor with great precision. The novel EV-interfering approach proposed by our study may become a new research direction in the complex interplay of modern personalized cancer therapy.

Made available in DSpace on 2020-12-12T01:27:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Canine mammary tumors (CMT) represent the most common neoplasms in female dogs and their diagnosis and classification relies on histopathological examination. Recently, PGRMC1 has been considered to be a putative biomarker for diagnosis and prognosis in many human cancers as it is expressed in a wide variety of tumors. This study represents the first description of PGRMC1 expression in CMT. PGRMC1 expression was initially assessed by immunohistochemistry in healthy or hyperplastic tissues and in four major histopathological types of CMT: simple and complex adenomas and carcinomas. PGRMC1 staining was represented by a scoring system that considered the percentage of positive cells and staining intensity. PGRMC1 expression was defined as either weak, moderate or strong. In healthy and hyperplastic tissues almost 100% of the epithelial cells stained intensely for PGRMC1. Adenomas showed similar features but with a more variable intensity. In tubular areas of adenocarcinomas, a lower percentage of epithelial cells (30–60%) stained for PGRMC1 with a weak intensity. Both the percentage of cells and intensity of PGRMC1 staining became progressively negative in the solid parts of the tumor. Western blot analysis of healthy and neoplastic mammary tissue (carcinomas samples) revealed the presence of the 25 kDa PGRMC1 band in both types of tissue, while the 50 kDa form was mainly detected in the healthy counterpart. This study reveals that PGRMC1 is expressed in CMT and its expression pattern changes depending on the pattern of growth of CMT. Further studies are now needed to determine PGRMC1's putative role and usefulness for typing and prognosis of different CMT subtypes. Reproductive and Developmental Biology Laboratory Department of Health Animal Science and Food Safety University of Milan Department of Veterinary Medicine University of Milan Department of Preventive Medicine and Animal Reproduction School of Agricultural and Veterinarian Sciences São Paulo State University (UNESP) Laboratory of Reproductive Physiology School of Veterinary Medicine São Paulo State University (UNESP) Department of Preventive Medicine and Animal Reproduction School of Agricultural and Veterinarian Sciences São Paulo State University (UNESP) Laboratory of Reproductive Physiology School of Veterinary Medicine São Paulo State University (UNESP)

A 7-year-old neutered female Doberman pinscher was presented with a palpebral nodule on the haired eyelid of the left eye. The nodule was removed surgically. Microscopically, the nodule was consistent with eyelid melanocytoma. The tumour was characterized by the presence of numerous lacunar and slit-like spaces filled by erythrocytes and interspersed throughout the neoplastic melanocytes. Immunohistochemically, these spaces were lined by cells expressing PNL2, but the cells were negative for factor VIII and CD31. [corrected] These findings were consistent with neoplastic melanocytes without endothelial cell participation. This feature was interpreted as 'vasculogenic mimicry', a mechanism of tumour angiogenesis that is well-recognized in human melanomas, but has not yet been reported in melanomas in animals.

We compared the performance of clinicopathologic and molecular tests used in the antemortem diagnosis of feline infectious peritonitis (FIP). From 16 FIP and 14 non-FIP cats, we evaluated retrospectively the sensitivity, specificity, and likelihood ratios (LRs) of serum protein electrophoresis, α1-acid glycoprotein (AGP) on peripheral blood, screening reverse-transcription nested PCR (RT-nPCR) on the 3’–untranslated region (3’-UTR), and spike (S) gene sequencing on peripheral blood, body cavity effusions, and tissue, as well as body cavity cytology and delta total nucleated cell count (ΔTNC). Any of these tests on blood, and especially the molecular tests, may support or confirm a clinical diagnosis of FIP. A negative result does not exclude the disease except for AGP. Cytology, 3’-UTR PCR, and ΔTNC may confirm a clinical diagnosis on effusions; cytology or 3’-UTR PCR may exclude FIP. Conversely, S gene sequencing is not recommended based on the LRs. On tissues, S gene sequencing is preferable when histology is highly consistent with FIP, and 3’-UTR PCR when FIP is unlikely. Combining one test with high LR+ with one with low LR− (e.g., molecular tests and AGP on blood, ΔTNC and cytology in effusions) may improve the diagnostic power of the most used laboratory tests.

Most canine tumors of the eyelid are tumors generally encountered in the skin. They are most commonly of epithelial origin and benign. In this report, we describe the cases of two sibling Czech wolfdogs presented, one year apart, with a subcutaneous mass involving the left eyelid. Both lesions were histologically consistent with a diagnosis of subcutaneous fibrosarcoma. Immunohistochemical analyses of the tumors revealed a mild positivity for vimentin and negativity for GFAP, desmin, αSMA, myoglobin, S100, PNL2 and calponin, excluding all differential diagnosis (i.e. peripheral nerve sheath tumor, melanoma, perivascular sarcoma, myofibroblastic sarcoma, rhabdomyosarcoma). To the best of authors’ knowledge, this is the first report of canine eyelid fibrosarcoma. Since this rare tumor has been observed in two full siblings, we could speculate the existence of some genetic predisposition to sarcoma, however the present data did not allow any definite conclusion on the etiopathogenesis or genetic basis of these tumors.Keywords: Dog, Eyelid tumor, Sarcoma, Siblings.

Simple Summary This case report describes the unusual presentation of two rare tumors in a mare diagnosed over a short period of time (9 months), affecting the eye and the mammary gland, with a relapse of the ocular tumor presenting histological features that cannot be attributed to any specific neoplastic entity. In the study, we describe the in vivo diagnosis and treatment of the neuroepithelial intraocular tumor and the post mortem detection of a metastatic malignant mammary carcinoma. Abstract A 24-year-old Irish Cob mare was presented with a peripheral iris mass, which was surgically resected and diagnosed as an undifferentiated neuroepithelial tumor. A few months later, a relapse occurred with histological features characterized by a more solid appearance and squamous differentiation. Subsequently, the mare was presented with rapidly spreading multiple subcutaneous masses and, at the onset of neurological signs, was humanely euthanized and subjected to a complete post mortem examination. The necropsy confirmed the presence of numerous widespread masses in the subcutaneous tissue, several internal organs, and mammary gland. Histological and immunohistochemical (IHC) examinations were performed on all masses, allowing the diagnosis of mammary carcinoma with several visceral and subcutaneous metastases. Considering the post mortem findings, the second intraocular mass was submitted to histological and IHC re-evaluation to differentiate it from an intraocular metastasis of the mammary carcinoma. The results of the histological and IHC analyses confirmed the diagnosis of neuroepithelial tumor relapse. This is the first case of a metastatic mammary carcinoma concurrent with a recurrent intraocular neuroepithelial tumor in a mare. This case was a challenge for both clinicians and pathologists involved and highlighted the importance of post mortem and IHC evaluations.

Lymph node (LN) metastasis is a negative prognostic factor in dogs with cutaneous mast cell tumours (cMCTs). While elective lymphadenectomy of metastatic LNs improves outcome, the benefit of adjuvant medical therapy in dogs with early metastatic (HN2) LNs is debated. The aim of this retrospective multicentre study was to evaluate the therapeutic benefit of adjuvant medical therapy following surgical removal of the primary low-grade cMCT (Patnaik grade 1-2 and Kiupel low-grade) and lymphadenectomy of HN2 LNs by analysing survival rates and patterns of recurrence. Seventy-three dogs were included: 42 received adjuvant medical treatment (chemotherapy and/or kinase inhibitors), and 31 did not. The median follow-up time for medically treated dogs was 619 days: two experienced local recurrence, three nodal relapse and four distant relapse. For dogs undergoing surgery only, the median follow-up time was 545 days. None of them experienced local recurrence, nodal, or distant relapse. Time to progression was significantly shorter in dogs receiving adjuvant medical treatment (P = .021). A similar tendency was observed for overall survival (P = .056). The current study shows that dogs with low-grade cMCTs, that undergo surgical excision of the primary tumour and elective lymphadenectomy of the HN2 regional LN harbour a good prognosis. The use of adjuvant medical treatment in these dogs does not seem to provide any benefit in terms of progression and survival.

In fluorescence microscopy, light radiation can be used to bleach fluorescent molecules in formalin-fixed and paraffin-embedded (FFPE) samples, in order to increase the ratio between signal of interest and background autofluorescence. We tested if the same principle can be exploited in bright field microscopy to bleach pigmented melanoma FFPE sections together with cell morphology maintenance. After dewaxing and rehydration, serial FFPE sections of a feline diffuse iris melanoma, a canine dermal melanoma, a gray horse dermal melanoma and a swine cutaneous melanoma were irradiated with visible light for 1, 2, 3, 4 and 5 days, prior to Hematoxylin and Eosin staining. Complete bleaching was obtained after 1-day treatment in feline and swine melanomas, while 2 and 3 days were required in canine and equine neoplasms, respectively. In all treated samples, cell morphology was maintained. Photo-induced bleaching combined with immunohistochemistry was tested after a 3-day photo-treatment using five different markers. According to the literature, in all samples neoplastic cells stained positive for vimentin, S100 and PNL2, while negative for FVIII and pancytokeratin. In conclusion, visible light can be effectively exploited to bleach pigmented melanoma FFPE sections prior to perform routine histochemical and immunohistochemical stains.

Local recurrence (LR) is the major concern in the treatment of feline injection-site sarcoma (FISS). Pretreatment leukocyte counts and ratios have been reported as diagnostic and/or prognostic markers in human and canine oncology. The aim of this retrospective study was to explore the prognostic impact on LR and overall survival time (OST) of pretreatment neutrophil-to-lymphocyte ratio (NLR), white blood cell count (WBCC), neutrophil count (NC) and lymphocyte count (LC) in cats with surgically excised FISS. Eighty-two cats with histologically confirmed FISS at first presentation, without distant metastases, and with available pretreatment haematological analyses were retrospectively enrolled. The correlation of NLR, WBCC, NC, LC with tumour variables and patient variables was explored. NLR was correlated with tumour size (P = .004), histological pattern of tumour growth (P = .024) and histotype (P = .029), while WBCC and NC were associated with ulceration (P = .007, P = .011) and pattern of growth (P = .028, P = .004). No significant relationships emerged between LC and any of the considered variables. The impact of NLR, WBCC, NC, LC on LR and OST was then estimated in univariate and multivariate analysis. In univariate analysis, NLR, WBCC and NC were significant prognostic factors for both LR and OST. NLR, WBCC and NC remained prognostic in multivariate analysis for LR but not for OST. When NLR, WBCC and NC were jointly analysed, WBCC was the marker with the greater impact on LR. Preoperative NLR, WBCC and NC may aid in identifying cats at higher risk of LR.

During testicular maturation, both Sertoli cells (SCs) and germ cells (GCs) switch from an immature to a mature immunophenotype. The reexpression of markers of immaturity in adults has been reported in cancer and in other testicular pathologies, in men as well as in animal species. Naturally affected with testicular cancer, rabbits have long been used in human reproductive research, but reports on the expression of testicular cell markers in this species are few and data about the immunophenotype of normal postnatal SCs and GCs are lacking. The aim of this study was to investigate the immunophenotype of SCs and GCs in the rabbit, from neonatal to adult age, using the antibodies anti-Müllerian hormone (AMH), vimentin (VIM), CKAE1/AE3 (cytokeratins [CKs]), desmin (DES), inhibin alpha (INH-α), placental alkaline phosphatase (PLAP), and periodic acid–Schiff (PAS) staining. In SCs, VIM was constantly expressed, and AMH and CKs expression was limited to neonatal and prepubertal age, whereas DES, INH-α, PLAP, and PAS were constantly negative. GCs were negatively stained for PLAP, PAS, and for the other markers. Results revealed analogies with human testicular immunophenotype, suggesting that rabbits could represent a potential experimental model for the study of human testicular pathology.

Feline primary cutaneous lymphomas (FPCLs) account for 0.2% to 3% of all lymphomas in cats and are more frequently dermal nonepitheliotropic small T-cell tumors. Emergence of FPCL seems unrelated to feline leukemia virus (FeLV) serological positivity or to skin inflammation. A total of 17 cutaneous lymphomas with a history of vaccine injection at the site of tumor development were selected from 47 FPCLs. Clinical presentation, histology, immunophenotype, FeLV p27 and gp70 expression, and clonality were assessed. A majority of male (12/17), domestic short-haired (13/17) cats with a mean age of 11.3 years was reported. Postinjection time of development ranged from 15 days to approximately 9 years in 5 cats. At diagnosis, 11 of 17 cats had no evidence of internal disease. Lymphomas developed in interscapular (8/17), thoracic (8/17), and flank (1/17) cutaneous regions; lacked epitheliotropism; and were characterized by necrosis (16/17), angiocentricity (13/17), angioinvasion (9/17), angiodestruction (8/17), and peripheral inflammation composed of lymphoid aggregates (14/17). FeLV gp70 and/or p27 proteins were expressed in 10 of 17 tumors. By means of World Health Organization classification, immunophenotype, and clonality, the lesions were categorized as large B-cell lymphoma (11/17), anaplastic large T-cell lymphoma (3/17), natural killer cell–like (1/17) lymphoma, or peripheral T-cell lymphoma (1/17). Lineage remained uncertain in 1 case. Cutaneous lymphomas at injection sites (CLIS) shared some clinical and pathological features with feline injection site sarcomas and with lymphomas developing in the setting of subacute to chronic inflammation reported in human beings. Persistent inflammation induced by the injection and by reactivation of FeLV expression may have contributed to emergence of CLIS.

Feline diffuse iris melanoma (FDIM) is the most common primary intraocular neoplasm in cats. It is usually a malignant tumor, even if slowly progressive, thus representing an unique spontaneous model of the aggressive, although rare, human iris melanoma. In cats, the extent of the tumor within the eye, expressed as histological grade, is considered a good predictor of survival. In the context of the neoplastic cells-tumor microenvironment interaction, Matrix Metalloproteinase-9 (MMP-9) is an endopeptidase able to digest the extracellular matrix with involvement in tumor invasion . MMP-9 expression has been positively correlated with metastasizing behavior in human posterior uveal melanoma. The present study investigates the expression of MMP-9 in a caseload of formalin-fixed paraffin-embedded FDIMs in relation to the histological grade and mitotic index (MI) (threshold=7/10 hpf). Sixty-one samples of FDIM evaluated on light microscopy (Fig. 1) were selected (grade I n=22, grade II n=20, grade III n=19). Immunohistochemical staining with standard ABC method was performed using a mouse anti-MMP-9 antibody. Results were semi-quantitatively scored and compared by Mann-Whitney U test. MMP-9 was expressed in 59,1% grade I FDIM, 90,0% grade II and 80,0% grade III. Tumors with MMP-9 expression in more than 50% of neoplastic cells were 13,6% in grade I cases, 40,0% in grade II and 36,8% in grade III. MMP-9 was expressed in 71,4% of FDIM with MI≤7 and 92,3% of FDIM with MI>7. MMP-9 expression differed significantly between grade I and the other two grades, and between groups with low and high MI. In conclusion, intense expression of MMP-9 seems to correlate with the histological aggressiveness of FDIM., International Journal of Health, Animal Science and Food Safety, Vol 5, No 1s (2018)

Omics techniques have been widely applied to veterinary science, although mostly on farm animal productions and infectious diseases. In canine oncology, on the contrary, the use of omics methodologies is still far behind. This review presents the most recent achievement in the application of postgenomic techniques, such as transcriptomics, proteomics, and metabolomics, to canine cancer research. The protocols to recover material suitable for omics analyses from formalin-fixed, paraffin-embedded tissues are presented, and omics applications for biomarker discovery and their potential for cancer diagnostics in veterinary medicine are highlighted.

Mixed germ cell sex cord stromal tumours (MGSCTs) are composed of seminiferous tubules, filled with admixed neoplastic Sertoli cells (SCs) and germ cells (GCs). The aim of the present study was to describe 13 canine testicular MGSCTs and to investigate the histochemical features and the immunophenotype of the neoplastic GCs and SCs. Neoplastic SCs were always diffusely labelled for vimentin (VIM), neuron specific enolase (NSE), inhibin (INH)-α and anti-Müllerian hormone (AMH). Cytokeratins AE1/AE3 (CK) and desmin (DES) were expressed in 6/13 and 8/13 cases, respectively. Neoplastic GCs were labelled for placental alkaline phosphatase (PLAP) in 7/13 cases and for CD117 (KIT) in 8/13 cases, while 10 cases were stained uniformly by periodic acid-Schiff (PAS). Immature canine SCs are known to express CK, DES, INH-α and AMH, while immature GCs are stained by PAS and express PLAP and KIT. This GC phenotype also distinguishes between classical and spermatocytic seminoma, with the latter being negative for these markers. The results of the present study show that both neoplastic SCs and GCs in MGSCTs have a de-differentiated phenotype.

Metastasis to regional lymph nodes (RLNs) in dogs with cutaneous mast cell tumour (cMCT) has been correlated with shortened survival time and higher risk of spread to distant sites. In the present study, extirpation of non-palpable or normal-sized RLNs was included in the surgical management of cMCT in dogs. Correlations between histological nodal status (HN0-3) and tumour variables were analysed. Ninety-three dogs with single cMCT without distant metastasis that underwent wide surgical excision of the primary tumour and extirpation of non-palpable or normal-sized RLN were included. The association between HN (HN0 vs HN > 0; HN0-1 vs HN2-3) and tumour variables (site, longest diameter, ulceration, 3-tier and 2-tier histological grades) was analysed by a generalized linear model with multinomial error. Then, 33 (35.5%) RLNs were HN0, 14 (15%) were HN1, 26 (28%) were HN2 and 20 (21.5%) were HN3. The presence of positive (HN > 0) RLN was significantly associated with cMCT larger than 3 cm. No other association was statistically significant. Non-palpable/normal-sized RLN in dogs with cMCT can harbour histologically detectable metastatic disease in nearly half of the cases. Extirpation of the RLN should always perfomed to obtain a correct staging of the disease, even in the absence of clinical suspicion of metastasis. Further studies should evaluate the possible therapeutical effect of the tumour burden reduction obtained by exrtipartion of a positive RLN.

Objectives Feline injection-site sarcomas (FISSs) are soft tissue tumours typically characterised by an interscapular location and highly infiltrative behaviour. CT is considered the modality of choice for FISS staging and double positioning (dynamic approach) was reported to successfully detect the exact extent of infiltration into the muscles. The aim of the present study was to investigate the utility of the dynamic approach in feline patients referred for preoperative staging of interscapular FISS. Methods Tumour volume estimates were compared between the ellipsoid and the semi-automated segmentation methods. Two radiologists blinded to the patient coding used images from each position to assess the extent of muscular infiltration. The distance between the neoplasm and the adjacent skeletal structures (scapulae, spinous processes) was recorded in both positions by a single radiologist. Results Fifty-nine of 84 neoplasms invaded the adjacent muscular structures, with up to 15 muscles infiltrated. Between the extended and flexed position the average estimated numbers of muscles infiltrated were 1.9 (extended) and 1.84 (flexed) for observer A and 1.89 (extended) and 1.85 (flexed) for observer B. Good agreement between observers was established, with higher tumour volumes detected via the ellipsoid method. Moreover, tumours with smaller volumes showed slightly decreased muscular infiltration. Marked difference in the recorded distance between the skeletal structures and the neoplasm in the two different positions was established (mean ± SD difference spinous processes: 9.74 ± 9.57 mm; mean ± SD difference scapulae: 15.15 ± 11.76 mm). Conclusions and relevance A dynamic approach should be used for a complete evaluation of the invasiveness of FISS along with appropriate methodology for tumour volume measurement, which could potentially alter the tomographic estimation of the real dimension of the neoplasms.

Canine aural cholesteatoma is an epidermoid cyst that forms in the middle ear cavity as a rare complication of otitis media but the aetiopathogenesis remains controversial. In the present study, 13 cases of canine aural cholesteatoma were investigated histologically and immunohistochemically and compared with cases of chronic otitis. The immunohistochemical investigation was performed using the following monoclonal antibodies: anti-cytokeratins (CK) 14, 16, 8/18, and 19, and anti-Ki67. The proliferative indexes (PIs) of cholesteatomata and otitis epithelium were calculated as the percentage of Ki67 positive nuclei/total nuclei. Histologically, the cholesteatomata were composed of a hyperplastic, hyperkeratotic epithelium (matrix) resting on a fibrous perimatrix, infiltrated by inflammatory cells and devoid of cutaneous adnexa. Immunohistochemically, the cholesteatoma epithelium was CK14- and CK16-positive, and CK8/18- and CK19-negative. A similar pattern of CK expression was found in otitis externa. In otitis media, ciliated epithelium stained CK8/18- and CK19-positive in all layers, CK14-positive in the basal layers, and CK16-negative. The mean PIs in cholesteatomata and otitides were 18.8 and 17.8, respectively. The immunohistochemical pattern of CK expression in cholesteatomata, when compared with chronic otitis, was suggestive of hyperproliferative epithelium, but its origin could not be demonstrated. Comparable PI values were obtained in cholesteatoma and in chronic otitis, which confirmed that Ki67 is a valuable indicator of a hyperproliferative state, but not a predictor of aggressiveness.