Clinicopathologic description of a cutaneous melanocytic tumor in a 1-year-old cat.

A feline cutaneous melanocytic tumor in a 1-year-old cat is reported. The cytologic, histologic, and immunohistochemical characteristics of the pediatric feline cutaneous melanocytoma are included. A solitary, black-colored nodule on the head was histologically diagnosed as the epithelioid type of melanocytoma. Immunohistochemically, the neoplastic melanocytes demonstrated immunoreactivity to the S100 and MelanA antibodies but not to the PNL2 antibody. Despite high mitotic counts (17/10HPFs) and a Ki67 index (33%) suggesting malignant melanoma, the patient exhibited a favorable 5-month outcome. The mitotic activity of the neoplastic cells may not provide a reliable prediction for feline melanocytic tumors.

Histopathological changes in testicular lesions in cats.

OBJECTIVES: The aim of this retrospective study was to describe the neoplastic and non-neoplastic lesions seen on histopathological examination of cat testes in Hong Kong between 2018 and 2024. METHODS: A total of 26 single or dual testes samples were collected from 18 cats by veterinarians at 14 veterinary clinics and submitted for histopathological examination. Laboratory records, including signalment, lesion location, age, breed and histopathological findings, were reviewed for each cat. RESULTS: Neoplastic testicular lesions were seen in three older cats (median age 8.5 years; range 3-17) compared with 18 non-neoplastic lesions in 15 cats (median age 1 year; range 0.5-3). The most common non-neoplastic lesions included inflammation (in the testes, epididymis, tunics and ductus deferens), cryptorchidism, and one case each of polyorchidism and epididymal cyst formation. Two of the testes with inflammation were identified on immunohistochemical staining as feline coronavirus-infected and one pair of testes was associated with the presence of extracellular Gram-negative bacteria at the lesion site. Three different neoplastic lesions were identified, one each of Sertoli cell tumour, leiomyoma and fibrosarcoma. CONCLUSIONS AND RELEVANCE: Non-neoplastic testicular lesions were most common, including inflammation, cryptorchidism, polyorchidism and epididymal cysts. To our knowledge, leiomyoma and fibrosarcoma have not been reported in cat testes before and represent important differential diagnoses for testicular lesions.

Most of the testicles examined from castrated cats because of disease noted by the owner had evidence of inflammation. Others were poorly developed because they had not descended correctly into the scrotum. Three cases of testicular cancer were noted and two of the types of cancer had not been reported in cats before but have been seen in humans.

Kidney sparing during surgical treatment of an adrenocortical carcinoma with renal vein invasion in a cat.

A 15-year-old domestic shorthair cat was presented with gastrointestinal signs, polyuria, polydipsia, and weakness. Abdominal bruit ("whooshing" sound from turbulent blood flow) and hypertension (systolic blood pressure: 200 mmHg) were present. A left adrenal gland mass was detected with abdominal ultrasonography; a subsequent CT examination identified a mass and a thrombus in the ipsilateral renal vein. Adrenalectomy and venotomy were completed but nephrectomy was not necessary. Histological diagnosis was an adrenocortical carcinoma. There were no clinical signs at a follow-up examination 30 mo after surgery. Key clinical message: This report describes successful surgical management of feline adrenocortical carcinoma with renal vein invasion without kidney damage. This case suggests that, after correct diagnosis and in well-selected cases, surgery to remove adrenal tumors and thrombi in cats, despite renal vein invasion, can be done with excellent short- and long-term outcomes.

Sauvegarde des reins lors du traitement chirurgical d'un carcinome corticosurrénalien avec invasion des veines rénales chez un chatUn chat domestique à poil court de 15 ans a été présenté avec des signes gastro-intestinaux, une polyurie, une polydipsie et une faiblesse. Des bruits abdominaux (« sifflement ¼ provenant d'un flux sanguin turbulent) et une hypertension (pression artérielle systolique: 200 mmHg) étaient présents. Une masse de la glande surrénale gauche a été détectée à l'échographie abdominale; un examen tomodensitométrique ultérieur a identifié une masse et un thrombus dans la veine rénale ipsilatérale. La surrénalectomie et la veinotomie ont été réalisées mais la néphrectomie n'a pas été nécessaire. Le diagnostic histologique était un carcinome corticosurrénalien. Il n'y avait aucun signe clinique lors d'un examen de suivi 30 mois après l'intervention chirurgicale.Message clinique clé:Ce rapport décrit la prise en charge chirurgicale réussie du carcinome corticosurrénalien félin avec invasion des veines rénales sans lésion rénale. Ce cas suggère qu'après un diagnostic correct et dans des cas bien sélectionnés, une intervention chirurgicale visant à éliminer les tumeurs surrénales et les thrombi chez les chats, malgré l'invasion des veines rénales, peut être réalisée avec d'excellents résultats à court et à long terme.(Traduit par Dr Serge Messier).

Ultrasonographic features of a gastric submucosal lipoma in a cat: A case study.

A 7-year-old Korean shorthair cat was admitted to our hospital with chronic constipation. Abdominal ultrasonography incidentally revealed a focal asymmetric gastric mass. The mass was submucosal and hypoechoic without loss of wall layering. Histopathological examination revealed a gastric submucosal lipoma (GSL). Although there have been reports of gastric submucosal fat infiltration in cats, there have been no reports regarding GSL. To our knowledge, this is the first report describing the ultrasonographic characteristics of GSL in a cat. Gastric submucosal lipoma should be considered as a differential diagnosis when a focal hypoechoic submucosal mass without loss of wall layering in the stomach is observed on ultrasound images. Key clinical message: This case report describes the ultrasonographic characteristics of GSL in a cat and aims to provide useful information for the diagnosis of lipoma occurring in the feline gastrointestinal tract. The ultrasonographic features and histological results we describe should be helpful in diagnosing submucosal lipoma in cats with similar conditions.

Caractéristiques échographiques d'un lipome sous-muqueux gastrique chez un chat: une étude de casUn chat coréen à poil court âgé de 7 ans a été admis à notre hôpital pour constipation chronique. L'échographie abdominale a révélé de manière fortuite une masse gastrique focale asymétrique. La masse était dans la sousmuqueuse et hypoéchogène sans perte de stratification murale. L'examen histopathologique a révélé un lipome sous-mucosal gastrique (GSL). Bien qu'il y ait eu des rapports d'infiltration de graisse dans la sous-muqueuse gastrique chez le chat, aucun rapport n'a été signalé concernant le GSL. À notre connaissance, il s'agit du premier rapport décrivant les caractéristiques échographiques du GSL chez un chat. Le lipome sous-muqueux gastrique doit être envisagé comme diagnostic différentiel lorsqu'une masse sous-muqueuse hypoéchogène focale sans perte de stratification de la paroi de l'estomac est observée sur les images échographiques.Message clinique clé:Ce rapport de cas décrit les caractéristiques échographiques du GSL chez un chat et vise à fournir des informations utiles pour le diagnostic des lipomes survenant dans le tractus gastro-intestinal félin. Les caractéristiques échographiques et les résultats histologiques que nous décrivons devraient être utiles pour diagnostiquer le lipome sous-muqueux chez les chats présentant des conditions similaires.(Traduit par Dr Serge Messier).

Bladder duplication in the male cat: the first case report in China.

BACKGROUND: Bladder duplication is a rare congenital lower urinary tract anomaly disease characterized by the presence of two bladders, possibly with duplication of the urethra. This disease is rarely reported in cats. The clinical symptoms are commonly occult, with increased difficulty in making a definitive diagnosis, especially if there is no obvious urethral duplication. The diagnosis is typically based on radiographs and ultrasound, with computer tomography serving as a more advanced imaging diagnostic modality. Cases of duplicated bladders with accessory tubular tissues are even scarcer in both human and veterinary medicine. CASE PRESENTATION: A 6-year-old male neutered cat was brought to the hospital because of vomiting and constipation. Cystography revealed increased soft tissue density of a fusiform structure in the lower middle abdomen. The purulent-filled cavitary structure and the accessory tubular structure were removed via surgery, and histopathological examination confirmed a double bladder with attached accessory tubular tissue. After antibiotic treatment, the cat recovered uneventfully. CONCLUSION: This is the first case of bladder duplication in China and the first case of feline bladder duplication with tubular structure attachment in the world. This information will provide a reference for the diagnosis and treatment of similar cases in the future.

Successful surgical resection of a multilobular osteochondrosarcoma arising from the costal cartilage in a cat.

A 10-year-old neutered male cross-bred cat was referred to our clinic for a solid mass tightly fixed to the right side of the thoracic wall from the 2nd to 4th ribs. Computed tomography revealed the mass had remarkable calcifications and arose from the 3rd costal cartilage. After removal, it was diagnosed histopathologically as a multilobular osteochondrosarcoma (MLO). For tumor resection, extremely wide surgical margins included 6 costal cartilages and 3 sternal segments were required; however, the tumor was successfully resected, followed by reconstruction of the thoracic wall using artificial materials. The cat recovered uneventfully and was good in health for ~4 y. This is apparently the first report of surgical resection of MLO from the costal cartilage of a cat. Key clinical message: To our knowledge, this is the first report of MLO from the costal cartilage in a cat, demonstrating aggressive surgical resection despite extremely wide surgical margins.

Résection chirurgicale réussie d'un ostéochondrosarcome multilobulaire provenant du cartilage costal chez un chatUn chat croisé mâle castré de 10 ans a été référé à notre clinique pour une masse solide bien fixée sur le côté droit de la paroi thoracique de la 2e à la 4e côte. La tomodensitométrie a révélé que la masse présentait des calcifications remarquables et provenait du 3e cartilage costal. Après retrait, il a été diagnostiqué histopathologiquement comme un ostéochondrosarcome multilobulaire (MLO). Pour la résection tumorale, des marges chirurgicales extrêmement larges comprenaient 6 cartilages costaux et 3 segments sternaux; cependant, la tumeur a été réséquée avec succès, suivie d'une reconstruction de la paroi thoracique à l'aide de matériaux artificiels. Le chat s'est rétabli sans incident et était en bonne santé pendant environ 4 ans. Il s'agit apparemment du premier rapport de résection chirurgicale de MLO du cartilage costal d'un chat.Message clinique clé:À notre connaissance, il s'agit du premier rapport de MLO du cartilage costal chez un chat, démontrant une résection chirurgicale agressive malgré des marges chirurgicales extrêmement larges.(Traduit par Dr Serge Messier).

[Thymoma in a young adult cat]. / Thymom bei einer jung-adulten Katze.

Thymomas and mediastinal lymphomas are the most common mediastinal neoplasms in cats. While mediastinal lymphoma occurs primarily in younger cats (approximately 2 to 4 years of age), thymomas are diagnosed almost exclusively in older cats. However, the following case shows that this is not necessarily always the case.A 3-year- and 11-month-old neutered male European Shorthair was presented with a preliminary report of exercise intolerance and restricted respiration. Both symptoms occurred primarily at high ambient temperatures. Radiographically, a mediastinal mass filled a significant part of the thoracic cavity. A computed tomographic examination and ultrasound-guided TruCut biopsy were performed. Histologic examination suggested a thymoma. A sternal thoracotomy and resection of the circumferential proliferation was conducted. Subsequent histopathologic examination confirmed the suspected diagnosis of a mediastinal thymoma. The cat recovered well postoperatively, and a clinical and radiographic follow-up examination was unremarkable after 8 months.

Feline gastrointestinal eosinophilic sclerosing fibroplasia associated with Candida albicans.

Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) is a rare and poorly understood disease characterised by the infiltration of eosinophils and the development of fibrous tissue within the gastrointestinal tract of cats. A 2-year-old female neutered Ragdoll was presented for signs consistent with extrahepatic biliary tract obstruction (EHBO), including jaundice, hyporexia and lethargy. Marked progressive hyperbilirubinemia and mild anaemia were also present. Abdominal ultrasonography suggested a duodenal mass and pancreatitis as the cause of EHBO. Cytopathological results from fine needle aspirates detected mast cells and eosinophils in the duodenal mass and eosinophils in the spleen and the liver, suggestive of a possible mast cell tumour. A cholecystojejunostomy and a duodenotomy were performed to divert the biliary outflow and obtain biopsy samples, respectively. Eosinophilic sclerosing fibroplasia in the duodenal mass and fungal elements in an abdominal lymph node were reported on histopathological examination. A pan-fungal PCR targeting ITS2 performed on DNA extracted from an abdominal lymph node detected Candida albicans. This report adds to the growing body of evidence that FGESF can occur in association with fungal infections.

Computed tomography angiography features of a retroperitoneal extra-adrenal paraganglioma in a cat.

A 7-year-old spayed female domestic shorthair cat was presented for evaluation of a large-volume abdominal space-occupying lesion. A computed tomography angiography examination detected a round retroperitoneal mass, in contact with the large abdominal vessels, characterized by an external hyperattenuating capsule and a larger hypoattenuating center. The capsule was soft-tissue attenuating with marked heterogenous contrast enhancement. The center was hypoattenuating pre- and post-contrast administration. The mass displaced both kidneys laterally and the descendent colon ventrally. The mesenteric veins and both phrenicoabdominal veins were markedly increased in diameter. However, the adrenals were not involved. On the excretory phase, no contrast enhancement was observed in either ureter, except for the proximal tract of the right ureter. At laparotomy, both ureters entered the mass that was adherent to the great abdominal vessels. The cytological diagnosis was retroperitoneal extra-adrenal paraganglioma. In cats, retroperitoneal extra-adrenal paragangliomas are very rare. This is the first computed tomography angiography report of a retroperitoneal extra-adrenal paraganglioma in a domestic cat. Key clinical message: This report describes the computed tomography angiography features of a rare case of a retroperitoneal extra-adrenal paraganglioma in a cat. These features could be taken into consideration to direct the diagnosis of a possible neuroendocrine origin for a retroperitoneal mass in a cat.

Caractéristiques de l'angiographie par tomodensitométrie d'un para-gangliome extra-surrénalien rétropéritonéal chez un chatUne chatte domestique à poils courts, âgée de 7 ans, stérilisée, a été présentée pour évaluation d'une lésion abdominale de grand volume occupant de l'espace. Un examen d'angiographie tomodensitométrique a détecté une masse rétropéritonéale ronde, en contact avec les gros vaisseaux abdominaux, caractérisée par une capsule externe hyper-atténuante et un centre hypo-atténuant plus large. La capsule présentait une atténuation des tissus mous avec une prise de contraste hétérogène marquée. Le centre était hypoatténuant avant et après l'administration le milieu de contraste. La masse a déplacé latéralement les deux reins et ventralement le côlon descendant. Le diamètre des veines mésentériques et des deux veines phrénico-abdominales était nettement augmenté. Cependant, les surrénales n'étaient pas impliquées. À la phase excrétrice, aucune augmentation de contraste n'a été observée dans les deux uretères, à l'exception du tractus proximal de l'uretère droit. Lors de la laparotomie, les deux uretères pénétraient dans la masse adhérente aux gros vaisseaux abdominaux. Le diagnostic cytologique était un paragangliome extra-surrénalien rétropéritonéal. Chez le chat, les para-gangliomes extra-surrénaliens rétropéritonéaux sont très rares. Il s'agit du premier rapport d'angiographie par tomodensitométrie d'un para-gangliome extra-surrénalien rétropéritonéal chez un chat domestique.Message clinique clé:Ce rapport décrit les caractéristiques de l'angiographie par tomodensitométrie d'un cas rare de paragangliome extra-surrénalien rétropéritonéal chez un chat. Ces caractéristiques pourraient être prises en considération pour orienter le diagnostic d'une éventuelle origine neuroendocrinienne d'une masse rétropéritonéale chez un chat.(Traduit par Dr Serge Messier).

Feline lung-digit syndrome: A differential diagnosis for shifting, waxing and waning lameness in a cat.

The clinical presentation, cytologic findings, radiographic findings, and postmortem assessment of a cat with primary pulmonary adenocarcinoma with multiple digital metastasis are described. An unusual shifting, waxing and waning pattern of lameness, suspected to be an early manifestation of digital metastasis before any gross lesions were visible, was documented. Initial cytologic finding of a lung nodule was equivocal for diagnosis of neoplasia despite being strongly suspicious. Palliative management was short-lived, with rapid progression culminating in widespread metastasis to multiple digits, muscles, and other organs. The diagnosis of pulmonary adenocarcinoma was confirmed via necropsy and histopathology. Key clinical message: This case report highlights that feline lung-digit syndrome is an important differential diagnosis for an acute, waxing and waning, shifting leg lameness in an older cat. This pattern of lameness should raise the index of suspicion for an underlying primary lung neoplasm, and thoracic imaging (radiographs) should be considered.

Syndrome pulmonaire-digital félin : un diagnostic différentiel des boiteries changeantes, croissantes et décroissantes chez un chatLa présentation clinique, les résultats cytologiques, les résultats radiographiques et l'évaluation post mortem d'un chat atteint d'adénocarcinome pulmonaire primaire avec métastases numériques multiples sont décrits. Un schéma inhabituel de boiterie, variable, croissante et décroissante, suspecté d'être une manifestation précoce de métastases digitales avant que des lésions macroscopiques ne soient visibles, a été documenté. La découverte cytologique initiale d'un nodule pulmonaire était équivoque pour le diagnostic de néoplasie bien qu'elle soit fortement suspecte. La prise en charge palliative a été de courte durée, avec une progression rapide aboutissant à des métastases généralisées à plusieurs doigts, muscles et autres organes. Le diagnostic d'adénocarcinome pulmonaire a été confirmé par autopsie et histopathologie.Message clinique clé :Ce rapport de cas souligne que le syndrome pulmonaire-digital félin est un diagnostic différentiel important pour une boiterie aiguë, croissante et décroissante et mobile des pattes chez un chat ágé. Ce type de boiterie devrait faire suspecter une tumeur primaire du poumon sous-jacente, et une imagerie thoracique (radiographies) devrait être envisagée.(Traduit par Dr Serge Messier).

Analysis of serum peptidome profiles of non-metastatic and metastatic feline mammary carcinoma using liquid chromatography-tandem mass spectrometry.

BACKGROUND: Feline mammary carcinoma (FMC) is a common aggressive and highly metastatic cancer affecting female cats. Early detection is essential for preventing local and distant metastasis, thereby improving overall survival rates. While acquiring molecular data before surgery offers significant potential benefits, the current protein biomarkers for monitoring disease progression in non-metastatic FMC (NmFMC) and metastatic FMC (mFMC) are limited. The objective of this study was to investigate the serum peptidome profiles of NmFMC and mFMC using liquid chromatography-tandem mass spectrometry. A cross-sectional study was conducted to compare serum peptidome profiles in 13 NmFMC, 23 mFMC and 18 healthy cats. The liquid chromatography-tandem mass spectrometry analysis was performed on non-trypsinized samples. RESULTS: Out of a total of 8284 expressed proteins observed, several proteins were found to be associated with human breast cancer. In NmFMC, distinctive protein expressions encompassed double-stranded RNA-binding protein Staufen homolog 2 (STAU2), associated with cell proliferation, along with bromodomain adjacent to zinc finger domain 2A (BAZ2A) and gamma-aminobutyric acid type A receptor subunit epsilon (GABRE), identified as potential treatment targets. Paradoxically, positive prognostic markers emerged, such as complement C1q like 3 (C1QL3) and erythrocyte membrane protein band 4.1 (EPB41 or 4.1R). Within the mFMC group, overexpressed proteins associated with poor prognosis were exhibited, including B-cell lymphoma 6 transcription repressor (BCL6), thioredoxin reductase 3 (TXNRD3) and ceruloplasmin (CP). Meanwhile, the presence of POU class 5 homeobox (POU5F1 or OCT4) and laminin subunit alpha 1 (LAMA1), reported as metastatic biomarkers, was noted. CONCLUSION: The presence of both pro- and anti-proliferative proteins was observed, potentially indicating a distinctive characteristic of NmFMC. Conversely, proteins associated with poor prognosis and metastasis were noted in the mFMC group.

Unusual sex chromosomal DSD in a domestic Shorthair cat with a 37,X/38,XY mosaic karyotype.

BACKGROUND: Sex chromosome abnormalities associated with disorders of sexual development (DSD) are rarely described in cats, mainly due to the lack of chromossome studies that precisely reveal the condition. Genetic approaches are therefore required in order to detect sex chromossomes abnormalities as variations in the number and structure of chromosomes, or the presence of a second cell line as mosaicim or chimerism. CASE PRESENTATION: A male Shorthair cryptorchid cat was presented with clinical signs of anorexia, tenesmus and hyperthermia. Ultrasonography revealed a fluid-filled structure, with approximately 1 cm in diameter, adjacent to the descending colon. Computed tomography evidenced a tubular structure, ventral to the descending colon and caudal to the bladder, which extended cranially, through two branches. Histopathological evaluation confirmed the presence of two atrophic uterine horns and one hypoplastic testicle with epididymis at the end of one of the uterine horns. The end of the other uterine horn was attached to a structure composed by a mass of adipocytes. Cytogenetic analysis revealed a mosaic 37,X/38,XY karyotype. The two cell lines were found in 15% and 85% of the lymphocytes, respectively. Genetic analysis confirmed the presence of SRY and ZFY genes in blood and hair bulbs, and revealed a marked reduction in SRY expression in the testicle. Additionally, this case presented exceptionally rare features, such as a Leydig' cell tumour and a chronic endometritis in both uterine horns. CONCLUSIONS: Complete imaging workup, cytogenetic analysis and SRY gene expression should be systematically realized, in order to properly classify disorders of sexual development (DSD) in cats.

Expression of programmed cell death protein 1 and programmed cell death ligand 1 in feline injection site fibrosarcomas.

Feline injection site fibrosarcomas represent a unique challenge in veterinary oncology due to their association with injection sites and aggressive behaviour. The study explores the expression of immune checkpoints programmed cell death protein 1 and programmed cell death ligand 1 in the malignancy, aiming to unravel their potential significance in tumour progression. The study included 31, archival diagnostic specimens of feline fibrosarcomas, located in the common injection sites. The programmed cell death protein 1 and programmed cell death ligand 1 expression in tumour cells and tumour infiltrating lymphocytes were assessed by immunohistochemical methods. Programmed cell death protein 1 and programmed cell death ligand 1 expression were observed in 84% and 81% of cases, respectively. In tumour infiltrating lymphocytes the PD-1 expression was observed in 71% of cases. Notably, higher programmed cell death protein 1 expression correlated with tumour grade and heightened inflammation score, suggesting a potential association with tumour aggressiveness. Similarly, programmed cell death ligand 1 expression exhibited a positive correlation with tumour grade and inflammation score. The observed findings suggest a potential role for programmed cell death protein 1 and programmed cell death ligand 1 in tumour progression and immune response within the tumour microenvironment. Moreover, this study contributes to a deeper understanding of feline injection site fibrosarcoma pathogenesis, emphasizing the importance of considering immunological perspectives in developing effective treatment strategies for this challenging condition. Further investigations are warranted to advance our knowledge and refine therapeutic approaches for feline injection site fibrosarcoma management.

EDA Missense Variant in a Cat with X-Linked Hypohidrotic Ectodermal Dysplasia.

Hypohidrotic ectodermal dysplasia is a developmental defect characterized by sparse or absent hair, missing or malformed teeth and defects in eccrine glands. Loss-of-function variants in the X-chromosomal EDA gene have been reported to cause hypohidrotic ectodermal dysplasia in humans, mice, dogs and cattle. We investigated a male cat exhibiting diffuse truncal alopecia with a completely absent undercoat. The cat lacked several teeth, and the remaining teeth had an abnormal conical shape. Whole-genome sequencing revealed a hemizygous missense variant in the EDA gene, XM_011291781.3:c.1042G>A or XP_011290083.1:p.(Ala348Thr). The predicted amino acid exchange is located in the C-terminal TNF signaling domain of the encoded ectodysplasin. The corresponding missense variant in the human EDA gene, p.Ala349Thr, has been reported as a recurring pathogenic variant in several human patients with X-linked hypohidrotic ectodermal dysplasia. The identified feline variant therefore represents the likely cause of the hypohidrotic ectodermal dysplasia in the investigated cat, and the genetic investigation confirmed the suspected clinical diagnosis. This is the first report of an EDA-related hypohidrotic ectodermal dysplasia in cats.

Clinical signs associated with severe ST segment elevation in three cats with a hypertrophic cardiomyopathy phenotype.

Three cats were presented for unusual collapsing episodes. Echocardiography revealed a hypertrophic cardiomyopathy (HCM) phenotype in each cat. Continuous electrocardiographic monitoring showed that the clinical signs coincided with periods of severe ST-segment elevation in each cat. The first cat was treated with amlodipine and diltiazem but did not improve and was euthanized due to poor quality of life. Postmortem examination revealed cardiac lymphoma without obstructive coronary disease. The second cat was thought to have cardiac lymphoma, based on pericardial effusion cytology, and was euthanized before starting therapy. The third cat was diagnosed with HCM and left ventricular outflow tract obstruction and was treated with atenolol and diltiazem. This treatment reduced the frequency of episodic clinical signs, but the cat subsequently developed congestive heart failure and was euthanized. This case series describes clinical signs associated with severe ST elevation in cats with an HCM phenotype, and their outcomes. Continuous electrocardiographic monitoring was necessary to detect transient ST elevation in each case.

Characterisation of Canine and Feline Breast Tumours, Their Metastases, and Corresponding Primary Cell Lines Using LA-REIMS and DESI-MS Imaging.

Breast cancer, a complex disease with a significant prevalence to form metastases, necessitates novel therapeutic strategies to improve treatment outcomes. Here, we present the results of a comparative molecular study of primary breast tumours, their metastases, and the corresponding primary cell lines using Desorption Electrospray Ionisation (DESI) and Laser-Assisted Rapid Evaporative Ionisation Mass Spectrometry (LA-REIMS) imaging. Our results show that ambient ionisation mass spectrometry technology is suitable for rapid characterisation of samples, providing a lipid- and metabolite-rich spectrum within seconds. Our study demonstrates that the lipidomic fingerprint of the primary tumour is not significantly distinguishable from that of its metastasis, in parallel with the similarity observed between their respective primary cell lines. While significant differences were observed between tumours and the corresponding cell lines, distinct lipidomic signatures and several phospholipids such as PA(36:2), PE(36:1), and PE(P-38:4)/PE(O-38:5) for LA-REIMS imaging and PE(P-38:4)/PE(O-38:5), PS(36:1), and PI(38:4) for DESI-MSI were identified in both tumours and cells. We show that the tumours' characteristics can be found in the corresponding primary cell lines, offering a promising avenue for assessing tumour responsiveness to therapeutic interventions. A comparative analysis by DESI-MSI and LA-REIMS imaging revealed complementary information, demonstrating the utility of LA-REIMS in the molecular imaging of cancer.

Spinal magnetic resonance imaging in cats: differences in clinical significance of intervertebral disk extrusion, intervertebral disk protrusion, and degenerative lumbosacral stenosis.

OBJECTIVE: To determine the occurrence of degenerative changes affecting the vertebral column in cats, assess their clinical significance, and determine the occurrence in cats with intervertebral disk herniation compared to other spinal diseases. ANIMALS: 114 client-owned cats. METHODS: Hospital records were retrospectively reviewed for cats with suspected myelopathy that had undergone spinal MRI. Signalment; history; neurological examination; neurolocalization; primary diagnosis; presence, type, and location of intervertebral disk herniation; and presence and location of other degenerative spinal changes (intervertebral disk degeneration [IVDD], spondylosis deformans [SD], end plate changes, dorsal compressions [DC], and foraminal stenosis [FS]) were recorded. RESULTS: 70% of cats showed at least 1 spinal degenerative change. The most common change was IVDD, followed by SD and intervertebral disk protrusion (IVDP), while intervertebral disk extrusion (IVDE), end plate changes, DC, and FS were uncommon to rare. Primary complaint was attributed to a degenerative condition in 22% of cats, including 100% with IVDE, 9% with IVDP, and 43% with degenerative lumbosacral stenosis (DLSS). The occurrence of degenerative spinal changes and number of intervertebral disks affected by IVDD significantly increased with age and body weight. Age was positively correlated with the occurrence of SD and DLSS. Intervertebral disk degeneration, IVDP, SD, DC, and FS were more prevalent in the lumbosacral junction. Cats with IVDD were significantly more likely to show IVDE and IVDP. CLINICAL RELEVANCE: This study revealed that in a population of cats presenting for signs of myelopathy, IVDE was always responsible for the clinical presentation, DLSS was commonly considered incidental, and IVDP was infrequently related to neurological signs.

Unlocking immunotherapy targets: programmed death 1 and its ligand and their correlation with tumour grade in feline injection site sarcoma.

In this study, the immunohistochemical expression of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1), which could facilitate a novel approach to immunotherapy for feline injection site sarcomas (FISSs), was investigated. Treatment strategies based on the suppression of this pathway are possible for tumours expressing PD-1/PD-L1. In this context, FISSs were histologically classified, the grade of sarcoma and the intensity of lymphocyte infiltration determined and PD-1 and PD-L1 expression evaluated in tumours of different grade. Tumours were immunolabelled for vimentin, S100, smooth muscle actin and sarcomeric actin. Fibrosarcoma was diagnosed in eight cases, undifferentiated sarcoma in one case, liposarcoma in one case and rhabdomyosarcoma in one case. PD-1 expression was found mainly in lymphoid infiltrations and macrophage-like cells, while PD-L1 was found primarily in tumour cells and infiltrated macrophage-like cells. By Pearson correlation analysis, tumour differentiation was found to have a moderate correlation with PD-1 (P <0.05) and a high correlation with PD-L1 (P <0.01). Tumour grade had a low correlation with PD-1 and a moderate correlation with PD-L1 (P >0.05). A moderate correlation was also detected between PD-1 and PD-L1 (P <0.05). It was concluded that the increased expression of PD-1 and PD-L1 may be associated with poor tumour differentiation and, therefore, poor prognosis in FISS.

Using a three-dimensional-printed device with the patient's maxillary dental impression allows to perform minimally invasive brain biopsies in dogs and cats: a preliminary study.

OBJECTIVE: To develop an innovative process for stereotactic brain biopsies in dogs and cats that would provide a definitive diagnosis and optimize the management of patients with brain lesions. ANIMALS: 4 dogs and 1 cat diagnosed with 1 or more brain lesion(s) underwent brain biopsies between March 24, 2023, and October 25, 2023. METHODS: Based on trajectories selected on images of MRI and CT scan performed on each patient, a computerized software program was used to design a 3-D-printed patient-specific device with maxillary dental impression located on a baseplate to secure the patient's head and with insertion ports for the biopsy instrumentations located on a C-arm. As proof of concept, the device was successfully used in 2 cadavers before being used on clinical patients. All biopsy samples were submitted for histopathological examination. RESULTS: Histological diagnosis was obtained in 80% (4/5) of the cases (choroid plexus tumor, astrocytoma, meningioma, and chronic meningoencephalitis of unknown origin). In 1 patient, the results of biopsy were nondiagnostic; postmortem diagnosis was consistent with a low-grade oligodendroglioma. All the patients were discharged within 24 hours after the procedure without complications. This novel stereotactic system allows the surgeon to perform safe, easy-to-use, inexpensive, and minimally invasive precise brain biopsies in dogs and cats, without complications. CLINICAL RELEVANCE: This unique technique could be applied to any size and type of skull and for any type of brain lesions and would provide diagnostic information that would be valuable for future treatment planning and prognosis.