Outcomes of dogs with apocrine gland anal sac adenocarcinoma treated via modified closed anal sacculectomy (2015-2022).

OBJECTIVE: To evaluate the postoperative complication rate and local recurrence rate of apocrine gland anal sac adenocarcinoma (AGASACA) in dogs surgically treated with a modified closed anal sacculectomy technique between 2015 and 2022. STUDY DESIGN: Observational clinical retrospective study. ANIMAL POPULATION: Forty-seven client-owned dogs histologically diagnosed with AGASACA. METHODS: Medical records were evaluated for patient demographics and history, physical examination findings, diagnostic imaging, incidence of concurrent neoplasia, postoperative complications, and incidence and time to local recurrence. Dogs with at least 150 days of follow-up were included in evaluation of local recurrence. RESULTS: Two dogs were euthanized at 4 and 11 days after surgery. Forty-five dogs were included for long-term local recurrence evaluation, with a median of 364 days of follow-up (range 156-2156 days). Only one dog (2.2%) developed local recurrence with a time to recurrence of 90 days. Postoperative complications were reported in 15 dogs (31.9%) and were considered minor in 14 dogs (93.3%) and major in one dog (6.7%). Mean survival time for the 20 dogs that were deceased as of November 1, 2022 was 521 days (range 156-1409 days) and the median survival time was 388 days. CONCLUSION: The modified closed anal sacculectomy technique resulted in a lower AGASACA local recurrence rate than previously reported in the veterinary literature with a comparable postoperative complication rate. CLINICAL SIGNIFICANCE: Given the low recurrence rate found in this study, the modified closed anal sacculectomy technique may reduce the need for adjuvant radiation therapy and potentially chemotherapy in AGASACA patients.

Retrospective Evaluation of Melphalan, Vincristine, and Cytarabine Chemotherapy for the Treatment of Relapsed Canine Lymphoma.

Dogs diagnosed with multicentric lymphoma often relapse following induction therapy within the first year of treatment. The primary aim of this study was to evaluate the tolerability of a novel drug combination using melphalan, vincristine, and cytarabine (MOC) for the treatment of relapsed lymphoma. On day 1, dogs were treated with vincristine (0.5-0.6 mg/m2 IV) and cytarabine (300 mg/m2 IV over 4-6 hr or subcutaneously over 2 days). On day 7, dogs were treated with melphalan (20 mg/m2per os). This 2 wk protocol was repeated for at least three cycles or until treatment failure. Twenty-six dogs were treated with MOC and met the inclusion criteria. Twenty-three dogs had toxicity data, and all experienced adverse events with the majority graded as mild. The overall response rate was 38%, which included 19% of dogs who achieved a complete response. The median progression-free survival was 29 days (range 1-280 days). The overall clinical benefit was 65% for a median of 37 days (range 33-280 days). MOC is a safe treatment option for relapsed lymphoma in dogs.

Successful Surgical Resection of an Ependymal Cyst in the Fourth Ventricle of a Dog.

Ependymal cysts represent congenital brain malformations rarely described in human medicine, where surgical resection is the treatment of choice. In veterinary medicine, only three cases have been previously reported, with one partially resected with surgery. A 6 yr old entire male American Staffordshire terrier was referred with a 4 mo history of incoordination and collapsing episodes with extensor rigidity. Neurological examination localized the lesion to the left central vestibular system and cerebellum. A brain computed tomography scan showed a hypoattenuating lesion with peripheral contrast enhancement in the fourth ventricle consistent with a cyst and secondary hydrocephalus. Treatment with prednisone was initiated, but despite an initial improvement, neurologic signs recurred and a suboccipital craniectomy to remove the cyst was performed. The cyst was first drained, and the capsule was carefully resected. The histopathological evaluation revealed a simple cubic to cylindrical epithelium with apical cilia and loose surrounding fibrillar tissue consistent with an intraventricular ependymal cyst. Four and a half years after surgery, the dog only shows short episodes of balance loss when turning abruptly but is otherwise neurologically normal. To the authors' knowledge, this is the first reported ependymal cyst in the fourth ventricle of a dog with successful surgical resection.

Establishment and characterization of a HER2-enriched canine mammary cancerous myoepithelial cell line.

BACKGROUND: Canine mammary tumors (CMTs) have a poor prognosis, along with tumor recurrence and metastasis. Cell lines are vital in vitro models for CMT research. Many CMT epithelial cell lines were reported. However, canine mammary myoepithelial cells, the contractile component of the canine mammary tissue were overlooked. This study aimed at establishing such a cell line. CMT-1 cell line was obtained from a canine mammary tumor CMT-1 and characterized molecularly through qPCR, western blotting, immunochemistry and immunofluorescence. Its doubling time, cytogenetic analysis and migration rate were evaluated using growth study, karyotype analysis and wound healing assay respectively. To determine its tumorigenesis, xenograft transplantation was performed. RESULTS: CMT-1 tumor was a complex canine mammary carcinoma that stained negative to estrogen receptors (ER) and progesterone receptors (PR), but positive to human epidermal growth receptor-2 (HER2), defined as HER2-enriched subtype. In this study, a CMT-1 cell line obtained from CMT-1 tumor was immune-positive to vimentin, α-SMA, p63 and negative to E-cadherin (E-cad), indicating CMT-1 cells were myoepithelial cells. It was successfully cultured for more than 50 passages showing the same immunoreactivity to ER, PR, and HER2 as the primary canine tumor. The doubling time of CMT-1 cell line was 26.67 h. The chromosome number of CMT-1 cells ranged from 31 to 64. A potential spontaneous epithelial to mesenchymal transition (EMT) was noticed during cell cultures. Potential EMT-induced CMT-1 cells showed no significance in migration rate compared to the original CMT-1 cells. CMT-1 cells was able to grow on a 3D culture and formed grape-like, solid, and cystic mammospheres at different time period. Inoculation of CMT-1 cells induced a complex HER2-enriched mammary tumor with metastasis in mice. CONCLUSIONS: A canine cancerous HER2-enriched myoepithelial cell line was successfully established and a canine mammosphere developed from myoepithelial cells was documented in this study. We are expecting this novel cell line and its associated mammospheres could be used as a model to elucidate the role of myoepithelial cells in CMT carcinogensis in the future.

Diagnosis and Surgical correction of salivary affections in buffaloes (Bubalus bubalis); a retrospective study.

AIM: This study aimed to describe the diagnosis and treatment of various surgical salivary affections in buffaloes. MATERIALS AND METHODS: This study included 135 buffaloes examined at Dakahlia Governorate between 2011 and 2022 suffering from various surgical salivary affections. The recorded surgical affections had salivary fistula (n = 44), ectasia of Stenson's duct (n = 11), ranula/mucocele (n = 46), and cervical sialocele (n = 34). The buffaloes were sedated using an intramuscular injection of xylazine (0.05 mg/kg) and local infiltration analgesia of lidocaine for specific surgical interventions. RESULTS: The salivary duct fistula cases were surgically corrected using a retrograde infusion of povidone-iodine into the duct and its double ligation with Prolene following fistulectomy. Intraoral marsupialization was done in buffaloes suffering from ectasia of the parotid duct. The mucocele /ranula was surgically incised with daily flushing with povidone-iodine. The cervical sialocele was treated by giving an elliptical excision on the sialocele, and sialoadenectomy of the mandibular salivary gland was performed to facilitate dynamic fluid/saliva drainage. A 92.5% of diseased buffaloes showed an uneventful recovery without any postoperative complications after the first treatment, whereas 7.5% of animals tended to recur. The most common and almost equally distributed salivary affections recorded in adult buffaloes were parotid duct fistula, mucocele, and cervical sialocele. The Stenson's duct ectasia was commonly registered in calves, being congenital. CONCLUSION: Ranula was the most common salivary affection encountered in adult buffaloes, closely followed by parotid duct fistulae and cervical sialoceles. Stenson's duct ectasia was the least encountered salivary affection in calves and was congenital. All salivary affections were corrected easily and safely, with satisfactory outcomes.

Mammary carcinoma: Comparative oncology between small animals and humans-New therapeutic tools.

The poor outcomes associated with mammary carcinomas (MCs) in dogs and cats in terms of locoregional recurrence, distant metastasis and survival, highlight the need for better management of mammary cancers in small animals. By contrast, the outcomes of women with breast cancer (BC) have dramatically improved during the last 10 years, notably thanks to new therapeutic strategies. The aim of this article was to imagine what could be the future of therapy for dogs and cats with MCs if it became inspired from current practices in human BC. This article focuses on the importance of taking into account cancer stage and cancer subtypes in therapeutic plans, on locoregional treatments (surgery, radiation therapy), new developments in endocrine therapy, chemotherapy, PARP inhibitors and immunotherapy. Ideally, multimodal treatment regimens would be chosen according to cancer stage and cancer subtypes, and according to predictive factors that are still to be defined.

Mucocutaneous subdermal plexus flap for complete excision of a malignant dermal and conjunctival melanoma in a dog.

PURPOSE: To perform a reconstructive blepharoplasty to obtain complete surgical excision of a darkly pigmented raised conjunctival-eyelid mass of the lower eyelid in a dog. ANIMAL STUDIED: A 7-year-old, female-spayed, Yorkshire Terrier was evaluated for a slowly progressive, dark brown-to-black raised mass of the lower left eyelid. Sampling of the mass via fine-needle aspirate or incisional biopsy was declined, and an excision of the mass with the goal to obtain complete margins and maintain normal eyelid function with cosmesis was elected. PROCEDURES: The lower palpebral conjunctival-eyelid pigmented mass was excised en bloc and the lower eyelid was reconstructed with a mucocutaneous subdermal plexus flap. RESULTS: Histopathology revealed a malignant dermal and conjunctivalmelanoma excised with complete margins (1-2 mm). Short-term complications included corneal ulceration and eschar formation, which resolved completely at the 1-month follow-up. Long-term complications included mild trichiasis with epiphora and porphyrin staining. Tumor recurrence was not observed during an 8-month follow-up period. CONCLUSIONS: The en bloc excision with mucocutaneous subdermal plexus flap was successful in obtaining complete surgical margins for a malignant conjunctival-eyelid melanoma. An excellent functional and cosmetic outcome was achieved without tumor recurrence during an 8-month follow-up period. A mucocutaneous subdermal plexus flap can be considered as a surgical option for malignant melanoma of the lower eyelid.

Factors affecting prognosis in canine subcutaneous mast cell tumors: 45 cases.

OBJECTIVE: To evaluate the clinical outcome of subcutaneous mast cell tumors (SQMCT) and to identify clinical and histological characteristics of more aggressive disease. STUDY DESIGN: Retrospective study. ANIMALS: Forty-five dogs with 48 SQMCTs. METHODS: Medical records were reviewed (2011-2021) for patient information, clinical, and histopathological data including multinucleation, necrosis, invasion into local muscle, an infiltrative growth pattern, tumor grade (if listed), mitotic index, and surgical margins. The presence of local recurrence, lymph node metastasis, survival time, and other parameters evaluating patient outcome were also recorded. RESULTS: Local recurrence occurred in 17.8% (8/45) of dogs, 11.1% (5/45) developed metastatic recurrence, and 26.7% (12/45) developed lymph node metastasis. Dogs with lymph node metastases had a median disease-free interval (DFI) of 194 days (18-1864), while median DFI was not reached for dogs without lymph node metastasis (p = .0012). Median survival time for dogs with lymph node metastasis was 551 days (110-2050) compared to 1722 days (10-1722) without metastasis (p = .0432). Local recurrence resulted in a significantly shorter median survival time of 551 days (80-2050) compared to 1722 days (10-1722) for dogs without local recurrence (p = .0038). Dogs with infiltrative tumors had a median DFI of 268 days (3-1722) and DFI for dogs without an infiltrative pattern had not reached median at 1864 days (10-1864) (p = .011). CONCLUSION: Lymph node metastasis decreased disease-free interval and survival. CLINICAL SIGNIFICANCE: Subcutaneous mast cell tumors may be a more aggressive disease than previously reported.

A modified full-thickness labial/buccal rotational flap reconstruction technique following bilateral rostral maxillectomy and nasal planectomy for resection of maxillary tumors: Technique and results in two dogs.

OBJECTIVE: To describe a naso-facial reconstruction technique following bilateral rostral maxillectomy and its functional and cosmetic outcomes. ANIMALS: Two dogs. STUDY DESIGN: Clinical case series. METHODS: Two dogs were presented with a right rostral maxillary mass. Preoperative biopsy and staging revealed a biologically high-grade and histologically low-grade fibrosarcoma (Hi-Lo FSA). A combined nasal planectomy and radical bilateral rostral maxillectomy was performed sparing the labial/buccal mucocutaneous flaps bilaterally. Surgery resulted in asymmetry of the width of the flaps; the narrower flap was rotated medially to reconstruct the lip and create an oral vestibule. The wider flap was rotated medially to cover the remaining dorsolateral opening of the nasal conchae. The flaps overlapped in a parallel manner, discretely concealing the nasal passages, and separating them from the oral cavity. Hemorrhage occurred in both dogs, with one dog requiring a blood transfusion postoperatively. RESULTS: Oral Hi-Lo FSA with tumor-free margins was confirmed in both dogs. Both dogs recovered uneventfully within 4 weeks. Owners reported being very satisfied with the functional (return to normal exercise/activities and uncompromised respiration) and cosmetic outcomes. Based on the owners' telephone follow up, no tumor recurrence was noted at 15 (Dog 1) and 6 (Dog 2) months postoperatively. CONCLUSION: The full-thickness bilateral labial/buccal rotational flaps were used successfully to reconstruct the rostral maxilla, external nose and facial defects involving the nasal cavity. The technique resulted in acceptable functional and cosmetic outcomes and can be considered for naso-facial reconstruction in selected cases.

A rare case of histiocytic proliferative disease in a cat.

A 7-year-old intact female domestic medium hair cat was examined at a veterinary clinic for a scabbed nodule over the right shoulder. Multiple nodules recurred at the same site after the first surgical excision, and a second surgical excision was performed. Histopathology demonstrated high-mitotic-rate neoplastic cells and therefore a histiocytic proliferative disease was initially suspected. The condition progressed rapidly within a 5-month period and the cat was euthanized due to sudden onset of severe dyspnea. Necropsy showed diffuse metastatic nodules in the lungs, confirming a histiocytic proliferative disease, with histiocytic sarcoma being the most likely differential diagnosis.

Un cas rare de maladie histiocytaire proliférative chez un chat. Une chatte domestique á poil moyen intacte de 7 ans a été examinée dans une clinique vétérinaire pour un nodule croûteux sur l'épaule droite. Plusieurs nodules sont réapparus au même site après la première excision chirurgicale, et une deuxième excision chirurgicale a été réalisée. L'histopathologie a mis en évidence des cellules néoplasiques á taux mitotique élevé et, par conséquent, une maladie proliférative histiocytaire a été initialement suspectée. L'état a progressé rapidement en l'espace de 5 mois et le chat a été euthanasié en raison de l'apparition soudaine d'une dyspnée sévère. L'autopsie a montré des nodules métastatiques diffus dans les poumons, confirmant une maladie proliférative histiocytaire, le sarcome histiocytaire étant le diagnostic différentiel le plus probable.(Traduit par Dr Serge Messier).

Scar revision for incompletely or narrowly excised soft tissue sarcomas in dogs.

Objective: Describe clinical features of dogs undergoing scar revision for incompletely or narrowly excised soft tissue sarcomas (STSs) in the absence of gross disease and to determine local recurrence rates following scar revision. Animals: Thirty-three dogs with 33 scars. Procedures: Medical records were reviewed to collect data on signalment, tumor details, pre-surgical diagnostic tests, surgical and pathologic findings for both the initial and revision surgeries, and clinical outcomes. Descriptive statistics were generated. Results: For the initial excision, cytology was performed before surgery in 45.5% (15/33) of dogs, and information on surgical margins was rarely reported [4.0% (1/25) of circumferential and 12.0% (3/25) of deep margins]. Microscopic evidence of residual STS was identified in 18.2% of scars. Recurrence occurred in 3.0% (1/33) of dogs [median follow-up of 1127 d (1 to 3192 d)]; this dog had had no evidence of residual tumor in the scar revision pathology. Conclusions: Despite the low identification rate of residual tumor, the local tumor recurrence rate was 3.0%, which is lower than what is historically reported for incompletely or narrowly excised STSs. Clinical relevance: Scar revision for incompletely or narrowly excised STSs resulted in durable tumor remission in the dogs of this study. Pre-surgical diagnostic tests were not often performed in this study; these may be considered before the first excision to plan surgical margins for potentially reducing the incidence of incomplete or narrow excision. Surgical reports should include details on circumferential and deep margins to guide pathologic interpretation and future scar revision, if required.

Révision des cicatrice pour les sarcomes des tissus mous incomplètement ou étroitement excisés chez le chien. Objectif: Décrire les caractéristiques cliniques des chiens subissant une révision de cicatrice pour des sarcomes des tissus mous (STSs) incomplètement ou étroitement excisés en l'absence de maladie macroscopique et pour déterminer les taux de récidive locale après la révision de cicatrice. Animaux: Trente-trois chiens avec 33 cicatrices. Procédures: Les dossiers médicaux ont été examinés pour recueillir des données sur le signalement, les détails de la tumeur, les tests de diagnostic pré-chirurgicaux, les résultats chirurgicaux et pathologiques pour les chirurgies initiales et de révision, et les résultats cliniques. Des statistiques descriptives ont été générées. Résultats: Pour l'excision initiale, une cytologie a été réalisée avant la chirurgie chez 45,5 % (15/33) des chiens, et les informations sur les marges chirurgicales ont été rarement rapportées [4,0 % (1/25) des marges circonférentielles et 12,0 % (3/25) des marges profondes]. Des preuves microscopiques de STS résiduel ont été identifiées dans 18,2 % des cicatrices. Une récidive est survenue chez 3,0 % (1/33) des chiens [suivi médian de 1127 jours (1 à 3192 jours)]; ce chien n'avait eu aucun signe de tumeur résiduelle dans la pathologie de révision de la cicatrice. Conclusions: Malgré le faible taux d'identification de tumeur résiduelle, le taux de récidive tumorale locale était de 3,0 %, ce qui est inférieur à ce qui est historiquement rapporté pour les STS incomplètement ou étroitement excisés. Pertinence clinique: La révision des cicatrices pour les STS incomplètement ou étroitement excisés a entraîné une rémission tumorale durable chez les chiens de cette étude. Les tests diagnostiques pré-chirurgicaux n'ont pas souvent été effectués dans cette étude; ceux-ci peuvent être envisagés avant la première excision pour planifier les marges chirurgicales afin de réduire potentiellement l'incidence de l'excision incomplète ou étroite. Les rapports chirurgicaux doivent inclure des détails sur les marges circonférentielles et profondes pour guider l'interprétation pathologique et la révision future de la cicatrice, si nécessaire.(Traduit par Dr Serge Messier).

Scar revision for incompletely or narrowly excised cutaneous mast cell tumors in dogs.

Objective: Describe clinical features and outcomes of dogs undergoing scar revision for incompletely or narrowly excised cutaneous mast cell tumors without gross disease. Animals: 52 dogs undergoing 54 scar revisions. Procedures: Retrospective record review with information collected on signalment, tumor type/location, pre-surgical diagnostics, surgical and pathologic findings for the first excision and scar revision surgeries, and follow-up. Descriptive statistics were generated. Results: Prior to initial excision, cytology was performed on 38.9% (21/54) of tumors and the initial surgery report rarely described surgical resection margins [14.6% (7/48) of surgeries]. Residual tumor was identified pathologically in 29.6% (16/54) of scars. Local recurrence following scar revision occurred in 3.7% (2/54) of all scars [median follow-up 881.5 d (range: 0 to 3317 d)]; both scars had either complete excision of residual mast cell tumor or no evidence of mast cell tumor on scar revision and neither dog received radiation therapy. Conclusions: Identification of residual disease was uncommon, and local recurrence was less common than previously reported for incomplete/narrow mast cell tumor excision. Clinical relevance: Scar revision of unplanned primary excisions appears to yield a high likelihood of durable tumor remission in patients. First opinion practitioners are encouraged to avoid unplanned excisions by informing the surgical plan with cytology of the primary tumor and detailing surgical margin excision which may facilitate revision, if necessary.

Révision des cicatrices pour des mastocytes cutanés incomplètement ou étroitement excisés chez le chien. Objectif: Décrire les caractéristiques cliniques et les résultats des chiens subissant une révision de cicatrice pour des tumeurs mastocytaires incomplètement ou étroitement excisées sans maladie grave. Animaux: Cinquante-deux chiens soumis à 54 révisions de cicatrice. Procédures: Examen rétrospectif des dossiers avec des informations recueillies sur le signalement, le type/l'emplacement de la tumeur, les diagnostics pré-chirurgicaux, les résultats chirurgicaux et pathologiques pour les premières chirurgies d'excision et de révision de cicatrice, et le suivi. Des statistiques descriptives ont été générées. Résultats: Avant l'excision initiale, une cytologie a été réalisée sur 38,9 % (21/54) des tumeurs et le rapport chirurgical initial décrivait rarement les marges de résection chirurgicale [14,6 % (7/48) des chirurgies]. Une tumeur résiduelle a été identifiée pathologiquement dans 29,6 % (16/54) des cicatrices. Une récidive locale après révision des cicatrices s'est produite dans 3,7 % (2/54) de toutes les cicatrices [suivi médian de 881,5 jours (intervalle : 0 à 3317 jours)] les deux cicatrices présentaient soit une excision complète du tumeur mastocytaire résiduel, soit aucun signe de tumeur mastocytaire lors de la révision de la cicatrice et aucun chien n'a reçu de radiothérapie. Conclusions: L'identification de la maladie résiduelle était rare et la récidive locale était moins fréquente que précédemment rapportée pour l'excision incomplète/étroite du tumeur mastocytaire. Pertinence clinique: La révision de la cicatrice des excisions primaires non planifiées semble donner une forte probabilité de rémission tumorale durable chez les patients. Les praticiens de première opinion sont encouragés à éviter les excisions non planifiées en informant le plan chirurgical avec la cytologie de la tumeur primaire et en détaillant les marges de l'excision chirurgicale ce qui peut faciliter la révision, si nécessaire.(Traduit par Dr Serge Messier).

A case of spermatic cord B-cell lymphoma relapsing to the brain in a dog.

A 13-year-old, intact male mixed-breed dog was referred to our clinic for lethargy and asthenia following an episode of gastroenteritis. As an incidental finding during abdominal ultrasound, a mass on the right spermatic cord was seen. Cytology of the mass revealed a monomorphic population of large, round cells with a lymphoid appearance. A bilateral orchiectomy was conducted, and histopathology revealed the presence of a B-cell lymphoma in the right spermatic cord. Based on clinical staging, which showed no involvement of other sites, no additional treatment was administered. Recheck evaluations were scheduled for every 3 mo thereafter. Five months after surgery, the dog developed left central vestibular syndrome with a paradoxical right-sided head tilt. An MRI of the brain showed multifocal lesions and, due to a rapidly worsening clinical condition, the dog was humanely euthanized. The histopathology of the brain lesions was consistent with B-cell lymphoma. Key clinical message: This is the first report of a primary spermatic cord lymphoma relapsing to the brain in a dog. Although rare, spermatic cord tumors should be included among the differential diagnoses for masses arising from the spermatic cord. If lymphoma is diagnosed, location to other sites, especially to the central nervous system, should be considered.

Un cas de lymphome à cellules B du cordon spermatique récidivant au cerveau chez un chien. Un chien de race mixte mâle intact de 13 ans a été référé à notre clinique pour léthargie et asthénie à la suite d'un épisode de gastro-entérite. Comme découverte fortuite lors d'une échographie abdominale, une masse sur le cordon spermatique droit a été observée. La cytologie de la masse a révélé une population monomorphe de grosses cellules rondes d'aspect lymphoïde. Une orchidectomie bilatérale a été réalisée et l'histopathologie a révélé la présence d'un lymphome à cellules B dans le cordon spermatique droit. Sur la base du stade clinique, qui n'a montré aucune implication d'autres sites, aucun traitement supplémentaire n'a été administré. Des évaluations de contrôle étaient programmées tous les 3 mois par la suite. Cinq mois après la chirurgie, le chien a développé un syndrome vestibulaire central gauche avec une inclinaison paradoxale de la tête du côté droit. Une IRM du cerveau a montré des lésions multifocales et, en raison d'une détérioration rapide de l'état clinique, le chien a été euthanasié sans cruauté. L'histopathologie des lésions cérébrales correspondait à un lymphome à cellules B.Message clinique clé :Il s'agit du premier rapport d'un lymphome primaire du cordon spermatique récidivant au cerveau chez un chien. Bien que rares, les tumeurs du cordon spermatique doivent être incluses dans les diagnostics différentiels des masses provenant du cordon spermatique. Si un lymphome est diagnostiqué, la localisation vers d'autres sites, en particulier vers le système nerveux central, doit être envisagée.(Traduit par Dr Serge Messier).

A feline case of multiple myeloma treated with bortezomib.

BACKGROUND: Multiple myeloma (MM) is an uncommon neoplasm in cats. There is no established standard of treatment due to the rare occurrence of this disease in cats. Bortezomib is a proteasome inhibitor that serves as the first-line drug for MM in humans, but its effectiveness currently is unknown in feline MM. We present here the case report of a feline MM that exhibited a favorable response to bortezomib. CASE PRESENTATION: The case was an 11-year-old non-castrated male domestic cat with light-chain MM presenting with clinical symptoms (anorexia, fatigue, and vomiting), mild azotemia, and pancytopenia. The cat failed on melphalan with prednisolone (MP), so bortezomib (Velcade) was initiated on Day 88. A total of 6 cycles of the treatment was performed, with each treatment cycle consisting of twice-weekly subcutaneous administration for 2 weeks followed by a 1-week rest. The dose of bortezomib was 0.7 mg/m2 for first week and 1.0 mg/m2 for second week in the first cycle. A dose of 0.7 mg/m2 was used for subsequent cycles. Prednisolone was used concomitantly in the first 2 cycles. Following treatment with bortezomib, clinical symptoms disappeared and a decrease in serum globulin and recovery of pancytopenia were noted. A monoclonal gammopathy, overproduction of serum immunoglobulin light chain, and Bence-Jones proteinuria that existed at diagnosis were undetectable on Day 123. A monoclonal gammopathy also was not detectable at the end of the bortezomib treatment (Day 213). Anorexia, fatigue, and marked bone marrow toxicity were experienced when bortezomib was administrated at a dose of 1.0 mg/m2, while no recognizable toxicity was observed at a dose of 0.7 mg/m2 throughout the treatment period. The case was placed on follow-up and there was no evidence of relapse as of Day 243. CONCLUSIONS: Bortezomib was effective and durable for the treatment of this case of feline MM after failure with MP. Bortezomib was well-tolerated in this cat at a dose of 0.7 mg/m2, but not at 1.0 mg/m2. Bortezomib appears to be a drug worthy of further study for the treatment of feline MM.

Beclin-1 is a novel predictive biomarker for canine cutaneous and subcutaneous mast cell tumors.

Mast cell tumors (MCTs) are the most common skin tumor of the dog, and accurately predicting their clinical behavior is critical in directing patient therapy, as they range from benign lesions to a fatal systemic disease. Grading is useful for prognosis, but it cannot predict the behavior of all MCTs. We hypothesized that biomarker immunolabeling in tumor tissues would correlate with patient morbidity and mortality. A clinically annotated tissue microarray (TMA) of primary, recurrent, and metastatic (to lymph node) canine dermal and subcutaneous MCTs was created. Some dogs whose MCTs were included in the TMA did not receive adjunctive treatment after surgical excision of the MCT, whereas others were treated with one or a combination of chemotherapy, radiation, or oral toceranib. Immunohistochemistry for beclin-1, an autophagy protein, was performed followed by digital image analysis. Beclin-1 immunolabeling was higher in recurrent tumors (mean H-score 110.8) than primary MCTs (mean H-score 73.5), and highest in lymph node metastases (mean H-score 138.5) with a significant difference in means (P < .001). While beclin-1 level was not prognostic, it was strongly predictive for survival after adjunctive treatment; dogs with high beclin-1-expressing tumors showed poorer survival compared to those with low beclin-1-expressing tumors (HR = 5.7, P = .02), especially in Kiupel high-grade tumors (HR = 16.3, P = .01). Beclin-1 immunolabeling was the only significant predictive factor by multivariable analysis (P = .04). These findings may improve our ability to predict the response to adjunctive therapy. Importantly, these data suggest that autophagy inhibitors may be useful in improving response to treatment for dogs with high-grade MCTs.

Meningioma with rhabdoid features: Pathologic findings in dogs.

Rhabdoid meningioma is a rare type of meningeal neoplasm in humans. This study reports the clinical, pathological, and ultrastructural features of 4 cases of canine meningioma with rhabdoid features. The cases were female and 8 to 12 years of age. Biopsies from complete surgical resections were examined for all cases. The whole brain with tumor recurrence was collected at necropsy in 2 dogs. Histologically, the tumors consisted of discohesive sheets of oval-polygonal cells with abundant eosinophilic cytoplasm and occasional paranuclear hyaline-like inclusions. Cells were intensely immunopositive for vimentin, negative for melan A and S100 protein in all cases, and showed variable immunolabeling for cytokeratin in 2 cases. Focal glial fibrillary acidic protein (GFAP)-immunopositive cells were present in 1 case. Ultrastructurally, the rhabdoid cells in case 1 contained prominent cytoplasmic whorls of intermediate filaments, recapitulating the ultrastructural features of rhabdoid meningioma in humans. In cases 2 and 3, the meningioma cells contained interdigitating cell processes folded in a maze-like fashion resembling rhabdoid-like meningioma in humans. In case 4, the voluminous cytoplasm contained many round-to-flattened mitochondria admixed with rough endoplasmic reticulum, indicating a predominant oncocytic differentiation and not the rhabdoid differentiation suggested by light microscopy. Thus, rhabdoid morphology occurs in different types of meningiomas, and ultrastructural findings are essential for a correct diagnosis.

Submucosal resection via a transanal approach for treatment of epithelial rectal tumors - a multicenter study.

OBJECTIVE: To report complications and long-term outcomes after submucosal resections of benign and malignant epithelial rectal masses. STUDY DESIGN: Retrospective multicentric study. SAMPLE POPULATION: Medical records of 93 dogs at 7 referral hospitals. METHODS: Records were reviewed for surgical time, diagnosis, margins, complications, and recurrences. Survival of dogs was evaluated based on tumor types, categorized as benign, carcinoma in situ, and carcinoma. The Kaplan-Meier survival curve and Cox proportional hazards analysis were used to determine the association of a range of variables with recurrence and survival time. RESULTS: Duration of follow up was 708 days (range, 25-4383). Twenty-seven dogs (29%) developed complications. Recurrence was identified in 20/93 (21%), with 12/20 recurrent masses treated with repeat submucosal resection. Median survival was not reached in any group. The 1-,2-, 5-year survival rates for carcinomas were 95%, 89%, and 73% respectively. However, overall survival was longer for benign tumors than carcinomas (P = .001). Recurrence was more likely when complications (P = .032) or incomplete margins (P = .023) were present. Recurrence was associated with an increased risk of death (P = .046). CONCLUSION: Submucosal resection of both benign and malignant rectal masses was associated with a low rate of severe complications and prolonged survival in the 93 dogs described here. CLINICAL SIGNIFICANCE: Submucosal resection is a suitable technique for resection of selected rectal masses.

Incomplete histological margins following planned narrow excision of canine appendicular soft tissue sarcomas and mast cell tumors, using the residual tumor classification scheme.

OBJECTIVE: To describe the frequency of incomplete histological margins following planned narrow excision (PNE) of mast cell tumors (MCTs) and soft tissue sarcomas (STSs), and to assess the residual tumor classification (R) scheme for reporting histological margins in clinical cases. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Forty-four client-owned dogs with 47 masses. METHODS: Medical records of dogs undergoing planned narrow excision of STSs and MCTs were reviewed (2016-2019). Histologic specimens were reviewed by a single pathologist and assigned R scoring (histologically incomplete/R1 margins defined as "tumor on ink"). RESULTS: Six out of 23 (26%) MCT PNEs and 10/42 (42%) of STS PNEs resulted in R1 margins. R1 margins were more likely when performing PNE with 6-10 mm lateral measured surgical margins (LMSMs) versus 0-5 mm LMSM for MCTs (1/14 vs 5/9), but not STSs (3/7 vs 7/17) (P = .049). The R scheme resulted in higher retrospective percentage agreement in histological reporting than defining incomplete histological margin as tumor cells within ≤1 mm of the margin (83% vs 68% agreement). Complications occurred in 12/47 surgeries, with none requiring additional surgery. Tumors recurred in 3/18 (17%) STSs and 2/18 (11%) MCTs. CONCLUSION: Fewer R1 margins were obtained when PNE with LMSM of 6-10 mm was performed for mast cell tumors. The use of the R scheme increased agreement in histopathological margin assessment. CLINICAL SIGNIFICANCE: Planned narrow excision is a viable technique for histopathological diagnosis of appendicular soft tissue sarcomas and mast cell tumors for limb salvage.

A case of colonic-colonic intussusception in a dog secondary to lymphoma treated with colonic resection and anastomosis.

A 2-year-old castrated male Great Dane crossbreed dog was presented with a history of diarrhea and suspected intussusception. Abdominal ultrasound revealed a colonic-colonic intussusception. The gastrointestinal tract was explored, and an approximately 5-cm intussusception was discovered mid-colon. All other gastrointestinal structures were normal in appearance. The intussusception could not be reduced manually. A colonic resection and anastomosis were performed together with a left-sided incisional colopexy. The dog recovered from surgery and histopathology revealed the intussusception to be secondary to large cell transmural lymphoma. Sections from the surgical margins revealed proliferation of fibrovascular tissue along the serosal surface segmentally, but no neoplastic cells were identified. The dog was subsequently treated with chemotherapy consisting of doxorubicin and prednisone. No evidence of disease recurrence was noted on ultrasound 9 months after surgery. Approximately 2 years after surgery, the dog is noted to be clinically normal at home with no abnormal findings on physical examination. A complete blood (cell) count and chemistry obtained at this time revealed no significant abnormalities besides mild azotemia. Additional restaging was declined by the owner.

Un cas d'intussusception colon-colon chez un chien secondaire à un lymphome traité par résection c olonique et anastomose. Un grand danois croisé mâle castré âgé de 2 ans a été présenté avec des antécédents de diarrhée et une suspicion d'intussusception. L'échographie abdominale a révélé une intussusception colon-colon. Le tractus gastro-intestinal a été exploré et une intussusception d'environ 5 cm a été découverte au milieu du côlon. Toutes les autres structures gastro-intestinales avaient un aspect normal. L'intussusception n'a pas pu être réduite manuellement. Une résection colonique et une anastomose ont été réalisées avec une colopexie incisionnelle du côté gauche. Le chien a récupéré de la chirurgie et de l'histopathologie a révélé que l'intussusception était secondaire à un lymphome transmural à grandes cellules. Des sections des marges chirurgicales ont révélé une prolifération de tissu fibrovasculaire le long de la surface séreuse de manière segmentaire, mais aucune cellule néoplasique n'a été identifiée. Le chien a ensuite été traité par une chimiothérapie composée de doxorubicine et de prednisone. Aucun signe de récidive de la maladie n'a été noté à l'échographie 9 mois après la chirurgie. Environ 2 ans après la chirurgie, le chien est cliniquement normal à la maison sans résultats anormaux à l'examen physique. Une numération sanguine (cellule) complète et l'analyse chimique obtenues à ce moment n'ont révélé aucune anomalie significative outre une légère azotémie. Une nouvelle restadification a été refusée par le propriétaire.(Traduit par Dr Serge Messier).

Kaplan-Meier Curves, Cox Model, and P-Values Are Not Enough for the Prognostic Evaluation of Tumor Markers: Statistical Suggestions for a More Comprehensive Approach.

The assessment of prognostic markers is key to the improvement of therapeutic strategies for cancer patients. Some promising markers may fail to be applied in clinical practice, or some useless markers may be applied, because of misleading results ensuing from inadequate planning of the study and/or from an oversimplified statistical analysis. This commentary illustrates and discusses the main issues involved in planning an effective clinical study and the subsequent statistical analysis for the prognostic evaluation of a cancer marker. Another aim is to extend the most applied statistical models (ie, those using Kaplan-Meier and Cox) to enable the choice of the best-suited methods for study endpoints. Specifically, for tumor-centered endpoints like tumor recurrence, the issue of competing risks is highlighted. For markers measured on a continuous numerical scale, a loss of relevant prognostic information may occur by setting arbitrary cutoffs; thus, the methods to analyze the original scale are explained. Furthermore, because the P-value is not a sufficient criterion to assess the usefulness of a marker in clinical practice, measures for evaluating the ability of the marker to discriminate between "good" and "bad" prognoses are illustrated. Several tumor markers are considered both in human and veterinary medicine. Given the similarity between markers for human breast cancer and canine mammary cancer, an application of the statistical methods discussed within the article to a public dataset from human breast cancer patients is shown.