Diagnosis, prognosis and treatment of canine cutaneous and subcutaneous mast cell tumors

Mast cell tumors (MCTs) are hematopoietic neoplasms composed of mast cells. It is highly common in dogs and is extremely important in the veterinary oncology field. It represents the third most common tumor subtype, and is the most common malignant skin tumor in dogs, corresponding to 11% of skin cancer cases. The objective of this critical review was to present the report of the 2nd Consensus meeting on the Diagnosis, Prognosis, and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors, which was organized by the Brazilian Association of Veterinary Oncology (ABROVET) in August 2021. The most recent information on cutaneous and subcutaneous mast cell tumors in dogs is presented and discussed

Brazilian consensus for the diagnosis, treatment and prognosis of cutaneous mast cell tumors in dogs

Mast cell tumors represent the most common malignant skin tumor in the dog. This review outlines the incidence, etiology and clinical signs of mast cell tumors. Diagnostic tests, staging and treatments are also discussed. This study was performed by the Veterinary Oncology and Pathology of UNESP, Jaboticabal and the Service of Pathology Veterinary, of UNESP-Botucatu with the support of the Brazilian Association of Veterinary Oncology and the Brazilian Association of Veterinary Pathology

RESPOSTA METABÓLICA AO TRAUMA CIRÚRGICO

The effects of surgical trauma on the organism, which are widely studied by human and veterinary medicine, result in a complex neuroendocrine and immune responses triggered to restore homeostasis and preserve life. The metabolic response to trauma is characterized by increased secretion of hypophyseal hormones, activation of the sympathetic nervous system, and secretion of pro-inflammatory cytokines. This response aims to maintain tissue perfusion, control the proliferation of microorganisms, and mobilize substrates to ensure the integrity of cellular functions and promote tissue repair. Different factors can influence the intensity of the organism’s response to trauma, including magnitude and duration of stimuli, pre-existing infirmities or traumas, anaesthetic protocols, and surgical techniques applied. Exacerbated metabolic responses can cause post-operative complications, prolonged recovery time, and death. By identifying the main events related to the metabolic response to surgical trauma, it is possible to act to reduce the associated damages, improving quality and minimizing the risks of the postoperative period. Thus, the present paper aims to present a review describing the physiopathology and the consequences of the metabolic response to surgical trauma, in its different forms and origins, in the perioperative period.Os efeitos do trauma cirúrgico no organismo, os quais são amplamente estudados pela medicina humana e veterinária, resultam em uma complexa resposta neuroendócrina e imunológica, desencadeadas para restabelecer a homeostase e preservar a vida. A resposta metabólica ao trauma é caracterizada pelo aumento da secreção de hormônios hipofisários, ativação do sistema nervoso simpático e secreção de citocinas pró-inflamatórias. Essa resposta tem por objetivo manter a perfusão tecidual, controlar a proliferação de microrganismos e mobilizar substratos para garantir a integridade das funções celulares e promover reparação tecidual. Diferentes fatores podem influenciar a intensidade da resposta do organismo ao trauma, incluindo magnitude e duração dos estímulos, enfermidades ou eventos traumáticos pré-existentes, protocolos anestésicos e técnicas cirúrgicas utilizadas. Respostas metabólicas exacerbadas ocasionam complicações pós-operatórias, tempo prolongado de recuperação dos pacientes e óbito. Através da identificação dos principais eventos relacionados à resposta metabólica ao trauma cirúrgico, é possível atuar de forma a reduzir os danos associados, melhorando a qualidade e minimizando os riscos do período pós-operatório. Sendo assim, este trabalho tem como objetivo apresentar uma revisão descrevendo a fisiopatologia e as consequências da resposta metabólica ao trauma cirúrgico, em suas diferentes formas e origens, no período perioperatório

Electrochemotherapy Associated with Calcium Electroporation in Metastatic Feline Cutaneous Malignant Melanoma

Background: Calcium electroporation (CaEP) is a novel therapeutic treatment that has been studied for cancer due to its selective killing cancer cells by necrosis and danger signals. Besides that, electrochemotherapy (ECT) is an effective local treatment that involves the administration of chemotherapeutic drugs followed by delivery of electrical pulses to the tumor. The combination with ECT and CaEP has been reported in literature suggesting that additional response of immune system could have been enhanced by electroporation with calcium. This case, report on the successful treatment with CaEP combined with ECT for treatment of a regional metastasis in a feline model of malignant melanoma.Case: A 9-year-old, mixed breed cat was referred to the veterinary clinic with a 2-month history of cutaneous peripalpebral plaque lesion (0.19 cm³) and a submandibular lymph node enlargement (0.5 cm³). Incisional biopsy of the cutaneous lesion and fine-needle aspiration of submandibular lymph node confirmed a cutaneous melanoma with submandibular lymph node metastasis. Tumor staging was set in T1N1M0 according to WHO staging criteria. ECT for the primary lesion and lymph node metastasis was proposed. For the ECT, bleomycin (15,000 UI/m²) application was performed intravenous followed by electroporation (8 pulses of 100 μs at 1000 V/cm, and 1 Hz) using a needle array electrode consisted of two parallel rows with six needles in each row. At 28-day post-ECT complete remission of the primary tumor and metastatic foci was achieved. However, 120 days after ECT, recurrence was observed in submandibular and retropharyngeal lymph nodes. A second ECT approach was performed adding to bleomycin the intra lymph nodal application of calcium gluconate. The dose of calcium gluconate was diluted in an isotonic 0.9% NaCl solution resulting in a low concentration at 9 mM, injected in both metastatic lymph nodes (submandibular total volume: 1.4 ml; retropharyngeal total volume: 0.5 mL) and pulses were delivered immediately after drug administration. No systemic adverse effects were observed. Local adverse effects were considered mild as transitory edema and ulceration post procedure. One-week post-ECT+CaEP, complete remission of local metastasis occurred. However, the patient achieved five months disease free interval, and died during a surgical approach, achieving nine months of survival time.Discussion: Feline cutaneous malignant melanoma is an aggressive disease with a short survival time for the patients with mean of 4.5 months. CaEP is a novel anticancer treatment that has been study in the past years due to its selective killing cancer cells by necrosis and danger signals. The CaEP induces supraphysiological calcium influx into neoplastic cells leading to acute ATP depletion and necrosis of tumor cells. This use could be an interesting therapeutic choice for both human and veterinary medicine. In this patient, it was demonstrated a good clinical response with its use, showing temporarily tumor remission from the case presented with disease free interval of five months when compared to other report of two months. This description showed that ECT associated with CaEP improved outcome of regional melanoma lymph node metastasis in a cat. However, further investigations are needed to understand the use of CaEP in patients for local control metastasis as well as evaluate the use of both modalities to determine its synergistic effect

Reconstructive Surgical Repair of a Forth Degree Iatrogenic Burn in a Dog

Background: Burns are uncommon in small animal surgery routine and represents a real therapeutic challenge. Skin can be affect in different degrees of deepness as superfcial, partial thickness, full thickness and full thickness affecting underlying tissues. Each degree has individual features. Progression through degrees can occur in the frst 24 h or if treatment is inadequate. This paper aims to describe therapeutic approach and surgical technique to treat a huge dorsal iatrogenic thermal burn injury. Case: A 4-year-old female German Shepard was referred to veterinary hospital after 11 days of elective ovariosalpingohisterectomy. The patient presented a severe skin injury with crusts, eschars, purulent discharge and myiasis on dorsal cervical, thoracic and lumbar region. Beside severity of the wound, animal present good general status and normal vital signs. Complete blood count and biochemical analysis were within normal ranges. Histopathologic analysis of a wound tissue sample revealed the presence of coagulation necrosis and inflammatory response. The absence of traumatic events, histopathologic result and wound features increased suspicious of an iatrogenic burn injury from a poorly regulated thermal mattress used during surgical intervention. “Rule of Nines” was estimated as 25% of total body surface area. Systemic antibiotics and topical treatment with 0.05% chlorhexidine digluconate and 2.5% silver sulfadiazine ointment followed by wet-wet bandage was performed after initial surgical debridement. Muscle and vertebral bone explosion were evident. Topical treatment with Silver Sulfadiazine and chlorhexidine persisted twice daily until granulation tissue formation. Pain killers and sedation were often necessary during bandage changes. At 65th day proceeded to en bloc excision of scar tissue and surgical reconstruction with skin advancement and recruitment technique. Tie-over dressing was applied to cover the fnal wound. After 14 days animal received hospital discharge, and was assessed bi-weekly for 60 days. Discussion: Besides great extension of the burn injury, patient’s age, absence of systemic involvement and fluid therapy or critical care the prognosis was good. Modifed “rule of nine” are used to estimate wound size in dogs. The wound was classifed as forth degree or full thickness injury due to exposed muscular layer and bone. Early debridement, standard topical and systemic treatment protocol applied granted good recovery of wound bed. Due to be uncommon in small animal routine, main diagnosis and therapeutic recommendations for veterinary patients are based on human data. Systemic antimicrobial drugs are usually not recommended due to low concentration in burned tissues, however, prophylactic use was necessary due to highly infected tissues and possible bacterial absorption from devitalized tissues. Delayed primary closure technique was necessary due to highly infection site and extension, which turns surgical approach hard to perform. After formation of a granulation tissue bed for wound reconstruction, surgical treatment was performed. Surgical reconstruction is indicated in large full thickness defects and for better cosmetic appearance. The correct use and regulation of thermal mattress can avoid burns that can be life threatening. This case report rises the important concept that even low contact temperatures when persistent for long time can cause burn injuries. Keywords: thermal, mattress, injury, dogs, plastic

Application of a Meshed Skin Graft in the Surgical Bed Immediately after Resection of Neurofibrosarcoma in the Distal Limb Region of a Dog

Background: Malignant peripheral nerve sheath tumors are neurogenic neoplasms that originate from cells that surround the axons of peripheral nerves. Surgery is the treatment of choice for peripheral nerve sheath tumors. They have a better prognosis when the lesion is in the extremity of a limb and the surgeon leaves wide peripheral margins after resection. However, this procedure makes local treatment a challenge due to difficult wound healing in this region. This report describes a successful case involving the use of a meshed skin graft immediately after resection of a neurofibrosarcoma in the distal region of the radius bone of a dog.Case: A 6-year-old Boxer bitch weighing 40 kg was admitted with a history of a round, firm, non-ulcerated skin nodule attached to the lateral side of the distal region of the right radius bone, which had been present for about 40 days. Fine needle aspiration cytology of the lesion showed the presence of mesenchymal cells, suggesting a sarcoma. Thus, the decision was made for an incisional biopsy to confirm the diagnosis and for the preparation of a subdermal pattern tubular flap for subsequent rotation and transposition to close the wound that would be formed after the complete removal of the lesion. After the 7th postoperative day, the diagnosis of low-grade neurofibrosarcoma was confirmed and due to the presence of necrotic onset in the middle portion of the tubular flap, further surgical intervention was scheduled for the resection of the tube flap, en bloc removal of the neoplastic lesion with peripheral margins of 2 cm, and wound closure with a free skin graft. A mesh skin graft was made with a portion of the right flank skin. The mesh graft was carefully implanted on the recipient bed using simple interrupted sutures with a 3-0 non-absorbable monofilament suture material. A dressing made with water-based sterile lubricating solution and gauze and a modified Robert Jones bandage were applied. The patient was treated with analgesic medication, antimicrobial therapy, and gastric protectors. The first bandage and dressing were changed after 48 h, and only warm physiological solution was used. Histopathological analysis confirmed the diagnosis of low-grade neurofibrosarcoma with free surgical margins. The dressing was changed every 72 h for up to 12 postoperative days, when the immobilization was removed, and wound cleaning could be completed at home using physiological solution and a dressing with nitrofurazone ointment. Granulation tissue was first seen at day 12, and at day 30 the wound was completely closed.Discussion: The primary closure of skin defects after the resection of tumors located in the distal portion of limbs is often not possible due to a lack of adjacent skin. Thus, grafts are commonly used to repair the skin in these areas using the technique presented in this report. In order to survive, skin grafts need a vascular bed capable of allowing new blood vessel connections with the implanted skin portion. There is no consensus in the literature on the best bed for graft implantations. In the case described in this study, a free mesh graft was implanted on a fresh wound without granulation tissue, which resulted in excellent clinical evolution and total survival of the graft. Excellent clinical results were achieved with the graft, since its survival and adherence to the recipient bed occurred without complications. The clinical result of this case suggests that the application of full-thickness mesh grafts to fresh wounds in distal limbs immediately after tumor resection is a good alternative when the surgical wound is too large (which prevents primary closure). Good preoperative planning associated with good surgical techniques and adequate postoperative management are essential for the success of the technique under these conditions

Correlation between Porcine and Human Skin Models by Optical Methods

Background: Topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) as precursors of protoporphyrin IX (PPIX) have been used in skin cancer treatment and other skin diseases. To establish new topical PDT, protocols are necessary first to conduct studies in vivo using animal skin models. The goal of this study is to evaluate the robust correlation between porcine and human skin models in vivo by optical methods to confirm the suitability of porcine skin models to predict drug behavior in the human skin on topical PDT protocols. Methods: The study was performed in vivo using porcine and human skin models. In human skin, ALA and MAL cream mixture samples were applied to the inner arm in a circular area of 1 cm2. In porcine skin, the cream was applied on the back in an area of 4 cm2, over which an occlusive dressing was placed. PPIX production was monitored for up to 5 h using widefield fluorescence imaging and fluorescence spectroscopy techniques. Results: Human skin models showed similar behavior to porcine skin models, which indicates high similarity between both models and confirms that porcine skin is an adequate model to establish new clinical PDT protocols in human volunteers

Estudo retrospectivo de osteossarcoma primário dos ossos da pelve em cães em um período de 14 meses

The osteosarcoma (OSA) is one of the most common malignant tumors of dogs. Large and giant-breed dogs are affected and the mean age of these dogs is about 7 years. The tumor usually involves the metaphyses of long bones and the treatment is radical amputation and chemotherapy with cisplatin. The therapy of neoplasia located in pelvis is difficult and usually don't accept by owners. This report describes the incidence of primary osteosarcoma in pelvis of dogs, during a period of fourteen months. Of the eight animals taken care with this neoplasia, a bigger frequency in the dogs of the race Rottweiler and German Pastor was observed. Amongst the bones that compose animal's pelvis was observed greater osteosarcoma incidence in ileum (6 cases). Lameness, functional impotence of pelvic member and pain had been the main observed clinical signals. In seven cases was found advanced involvement osseous, mainly, for lyses of the cortical. All the animals had been submitted to the euthanasia for not presenting possibility of surgical treatment with safety margin. Also one was taken in consideration for this decision to the clinical condition of the patients, the possibilities to confer improvement in the quality of life of the dogs and the option of the owners' front to the prognostic.O osteossarcoma (OSA) é um dos tumores malignos mais comum em cães. Geralmente acomete cães de raça grande e gigante, com idade média de sete anos. Esta neoplasia envolve, freqüentemente, a metáfise de ossos longos, sendo indicado à amputação radical do membro, acrescido de quimioterapia com cisplatina. A terapêutica desta neoplasia com localização na pelve torna-se difícil e normalmente não aceita pelos proprietários. O presente trabalho relata a incidência de osteossarcoma primário em ossos da pelve em cães, durante um período de 14 meses. Dos oito animais atendidos com esta neoplasia, observou-se maior freqüência nos cães da raça Rottweiler e Pastor Alemão. Dentre os ossos que compõem a pelve do animal se observou maior incidência de OSA acometendo o ílio (6 casos). Claudicação, impotência funcional de membro pélvico e dor foram os principais sinais clínicos observados. Em sete casos encontrou-se estágio avançado de comprometimento ósseo na imagem radiográfica, evidenciado, principalmente, pela lise da cortical óssea. Todos os animais foram submetidos à eutanásia por não apresentarem possibilidade de tratamento cirúrgico (hemipelvectomia) com margem de segurança. Também se levou em consideração para esta decisão à condição clínica dos pacientes, as chances de conferir melhora na qualidade de vida dos cães e a opção dos proprietários frente ao prognóstico

Reparação do retalho axial dorsal em ratos tratados com óleo ozonizado

O retalho de padrão axial representa uma importante opção na cirurgia reconstrutiva, sendo composto por uma artéria e uma veia cutânea direta em sua base, permitindo que uma grande área de pele possa constituir o retalho para recobrir a ferida. Entretanto, a técnica pode apresentar complicações, principalmente com a necrose devido ao comprometimento vascular. Nesse contexto, a ozonioterapia pode ser utilizada para acelerar o processo de cicatrização de feridas pouco vascularizadas e contaminadas. Com o presente estudo, objetivou-se avaliar os efeitos e o reparo do retalho axial dorsal em ratos Wistar, empregando tratamento com óleo ozonizado de alta peroxidação. Utilizaram-se 18 ratos, distribuídos em dois grupos com 9 animais, grupo GG (óleo de girassol comum) e grupo GO (óleo de girassol ozonizado). Durante o período experimental foram realizadas avaliações macroscópicas e microscópicas a fim de observar a cicatrização e a reparação da ferida cirúrgica. Os dados foram submetidos a análise estatística.  O aspecto cosmético em GO foi significativamente melhor que GG, e a contagem de vasos sanguíneos, hemorragia e reepitelização foram significativamente maiores em GO quando comparado ao GG. A presença de necrose não diferiu entre os grupos. A média da área total dos retalhos entre os grupos diferiu estatisticamente, sendo maior nos retalhos em GO. Os resultados evidenciaram que a utilização do óleo ozonizado em retalhos de padrão axial resulta em aspecto favorável e melhor reepitelização

Reparação do retalho axial dorsal em ratos tratados com óleo ozonizado

Axial pattern flaps represents an important option in reconstructive surgery, consisting of an artery and a direct cutaneous vein at their base and allowing a large area of skin to form the flap to cover the wound. However, the technique can present complications, mostly necrosis due to vascular involvement. In this context, ozone therapy can be used to accelerate the healing process of poorly vascularized and contaminated wounds. The objective of this article was to evaluate the effects and repair of the dorsal axial flap in Wistar rats at the receiving bed, using treatment with high-peroxidation ozonized oil. The study was carried out with 18 rats, divided into two groups with 9 animals: GG group (comum sunflower oil) and GO group (ozonized sunflower oil). During the experimental period, macroscopic and microscopic evaluations were carried out, in order to observe the healing and repair of the surgical wound. Data were submitted to statistical analysis. The cosmetic appearance on GO was significantly better than GG. Blood vessel count, hemorrhage and reepithelialization were significantly higher in GO when compared to GG, while the presence of necrosis did not differ between groups. The mean total area of the flaps between the groups was statistically different, higher in the flaps in GO. The results showed that the use of ozonized oil in an axial pattern flap results in a favorable cosmetic appearance and better re-itemization in the treated group.O retalho de padrão axial representa uma importante opção na cirurgia reconstrutiva, sendo composto por uma artéria e uma veia cutânea direta em sua base, permitindo que uma grande área de pele possa constituir o retalho para recobrir a ferida. Entretanto, a técnica pode apresentar complicações, principalmente com a necrose devido ao comprometimento vascular. Nesse contexto, a ozonioterapia pode ser utilizada para acelerar o processo de cicatrização de feridas pouco vascularizadas e contaminadas. Com o presente estudo, objetivou-se avaliar os efeitos e o reparo do retalho axial dorsal em ratos Wistar, empregando tratamento com óleo ozonizado de alta peroxidação. Utilizaram-se 18 ratos, distribuídos em dois grupos com 9 animais, grupo GG (óleo de girassol comum) e grupo GO (óleo de girassol ozonizado). Durante o período experimental foram realizadas avaliações macroscópicas e microscópicas a fim de observar a cicatrização e a reparação da ferida cirúrgica. Os dados foram submetidos a análise estatística.  O aspecto cosmético em GO foi significativamente melhor que GG, e a contagem de vasos sanguíneos, hemorragia e reepitelização foram significativamente maiores em GO quando comparado ao GG. A presença de necrose não diferiu entre os grupos. A média da área total dos retalhos entre os grupos diferiu estatisticamente, sendo maior nos retalhos em GO. Os resultados evidenciaram que a utilização do óleo ozonizado em retalhos de padrão axial resulta em aspecto favorável e melhor reepitelização