RESUMO
Background: Squamous cell carcinoma (SCC) is a malignant neoplasm associated with prolonged exposure to ultraviolet light and lack of skin pigment in white-coated animals. The disease diagnosis is based on the animal's history, clinical signs and histopathology of the samples collected. The therapeutic alternatives are diverse. Among them, one of the most used is the metronomic chemotherapy which is based on the use of cytostatics drugs, applied in low and frequent doses for a longer period of time. One of the mechanisms of action of this type of therapy is the decrease in angiogenesis. Non-steroidal anti-inflammatory drugs (NSAIDs) are simultaneously used to maximize the angiogenic effect. The objective of this study is to report the results of a treatment accomplised with metronomic chemotherapy (cyclophosphamide with meloxicam) in a domestic feline which presented a squamous cell tumor. Case: A 7-year-old female cat, mixed breed, not neutered, weighing 3.5 kg, was assisted at the Veterinary Specialties Teaching Clinic (CEEV) of the Technical University of Machala (UTMACH), presenting bilateral ulcerative lesion in the nasal plane for 5 months. Chronic exposure to sunlight is referred to in the patient's anamnesis. Aspiration cytology performed in the patient revealed an inflammatory process with a predominance of neutrophils and macrophages, and showed absence of neoplastic cells. A treatment based on antibiotics and corticosteroids was adopted. As there were no favorable results, an excisional biopsy procedure was chosen to collect the affected tissues. The result of the histopathological analysis was a level 2 squamous cell carcinoma (SCC). The initial treatment consisted of surgical removal of the tumor and later the use of metronomic chemotherapy based on Cyclophosphamide, Meloxicam, DHA (docosahexaenoic acid) and Sucralfate for 5 months was adopted. At the beginning of the second phase of treatment, the patient developed a macula that progressively diminished. Currently, the patient does not have any recurrence of the diagnosed neoplasm. Discussion: The diagnosis of squamous cell carcinoma was based on clinical and histopathological findings. The macroscopic lesions were crusted ulcers that do not heal in the nasal plane and auricular pavilion, as reported in the literature. SCC is characterized by the infiltration of squamous cells in the dermal layer of the skin, forming epithelial islands with keratin pearls. The histopathological findings of this case present the same characteristics. The climatic conditions of Ecuador, high temperatures with greater incidence of sunlight, hypopigmented areas of the animal's body and chronic exposure to solar radiation are risk factors present in this case that foster the development of this malignant neoplasm. There are multiple treatments to be introduced in this sort of pathology. In this case, surgical removal of the tumor was adopted, followed by metronomic chemotherapy based on cyclophosphamide at 10 mg/m2 and meloxicam at a 0.05 mg/kg per day for a period of time of five months, obtaining favorable results and absence of recurrence. Despite metronomic chemotherapy being easy to administer, with fewer side effects, which includes a better acceptance of care takers who are reluctant to administer conventional chemotherapy, further studies are still necessary in what concerns certain variables such as age, carcinoma level, appropriate dosages and drugs according to each neoplasm.
Assuntos
Animais , Feminino , Gatos , Carcinoma de Células Escamosas/tratamento farmacológico , Citostáticos/administração & dosagem , Administração Metronômica/veterinária , Neoplasias Cutâneas/veterináriaRESUMO
Background: Transmissible venereal tumor (TVT) is a highly contagious round cell neoplasm that affects dogs, and itis usually transmitted through coitus. The tumor is mainly located in the genital area; however, the neoplasm can also beextragenital, affecting the nose, mouth, and eyes, as well as the skin and superficial lymph nodes. Cytological examinationis the most commonly used method for definitive diagnosis due to its low cost and fast execution. Chemotherapy, radiotherapy, surgical resection, and other procedures such as cryosurgery are the possible treatment options. The objective ofthis report was to describe a case of extragenital TVT with nasal primary site and metastasis in the bone tissue in a dogtreated at a private veterinary hospital in the city of Belém, Pará, Brazil.Case: A 6-year-old male domiciliary Labrador Retriever dog, weighing 24.2 kg, received oncologic treatment in a privateveterinary hospital in the city of Belém, Pará, Brazil. The animal had a history of neoplastic disease, and he had undergoneTVT resection associated with chemotherapy treatment more than 3 years ago. The clinical examination revealed a volumeincrease in the periorbital region, left lateral ocular displacement, left nostril excessive epistaxis, recurrent sneezing, cough,and pain signs, and tumor metastasis was suspected. Complementary exams of oncological cytology, computed tomography(CT), hemogram, and serum biochemistry were requested for diagnosis and staging of the condition, and supportive therapywas prescribed. The cytological report showed a dense population of neoplastic round cells with characteristics of TVT. CTindicated the presence of a heterogeneous hypodense mass with irregular contours and partially defined limits, with slightuptake of the intravenously injected contrast medium that obliterated the nasal cavity, maxillary recess, nasopharyngealmeatus, frontal sinus, and sphenoid sinus on the left side...(AU)
Assuntos
Animais , Cães , Tumores Venéreos Veterinários/complicações , Tumores Venéreos Veterinários/diagnóstico por imagem , Neoplasias Ósseas/secundário , Neoplasias Ósseas/veterinária , Neoplasias Nasais/veterinária , Lomustina/uso terapêutico , Tomografia Computadorizada por Raios X/veterinária , Administração Metronômica/veterináriaRESUMO
Background: Transmissible venereal tumor (TVT) is a highly contagious round cell neoplasm that affects dogs, and itis usually transmitted through coitus. The tumor is mainly located in the genital area; however, the neoplasm can also beextragenital, affecting the nose, mouth, and eyes, as well as the skin and superficial lymph nodes. Cytological examinationis the most commonly used method for definitive diagnosis due to its low cost and fast execution. Chemotherapy, radiotherapy, surgical resection, and other procedures such as cryosurgery are the possible treatment options. The objective ofthis report was to describe a case of extragenital TVT with nasal primary site and metastasis in the bone tissue in a dogtreated at a private veterinary hospital in the city of Belém, Pará, Brazil.Case: A 6-year-old male domiciliary Labrador Retriever dog, weighing 24.2 kg, received oncologic treatment in a privateveterinary hospital in the city of Belém, Pará, Brazil. The animal had a history of neoplastic disease, and he had undergoneTVT resection associated with chemotherapy treatment more than 3 years ago. The clinical examination revealed a volumeincrease in the periorbital region, left lateral ocular displacement, left nostril excessive epistaxis, recurrent sneezing, cough,and pain signs, and tumor metastasis was suspected. Complementary exams of oncological cytology, computed tomography(CT), hemogram, and serum biochemistry were requested for diagnosis and staging of the condition, and supportive therapywas prescribed. The cytological report showed a dense population of neoplastic round cells with characteristics of TVT. CTindicated the presence of a heterogeneous hypodense mass with irregular contours and partially defined limits, with slightuptake of the intravenously injected contrast medium that obliterated the nasal cavity, maxillary recess, nasopharyngealmeatus, frontal sinus, and sphenoid sinus on the left side...
Assuntos
Animais , Cães , Lomustina/uso terapêutico , Neoplasias Nasais/veterinária , Neoplasias Ósseas/secundário , Neoplasias Ósseas/veterinária , Tumores Venéreos Veterinários/complicações , Tumores Venéreos Veterinários/diagnóstico por imagem , Administração Metronômica/veterinária , Tomografia Computadorizada por Raios X/veterináriaRESUMO
Background: Urethral tumors are uncommon in canines, represented predominantly by transitional cell carcinoma, marked by aggressive behavior associated with short life expectancy. Definitive diagnosis is achieved by histopathological analysis. Surgery associated with chemotherapy is the main therapeutic alternative. The aim of this paper is to report a case of primary transitional cell carcinoma of the urethra in a bitch, submitted to surgical treatment associated with conventional adjuvant chemotherapy and metronomic chemotherapy, achieving survival of 21 months, to date. Case: A 12-year-old bitch mixed breed was admitted at the Veterinary Hospital of Federal Rural University of Rio de Janeiro (UFRRJ), manifesting hematuria and urinary incontinence for one month. Physical examination indicated that vital parameters were within normal limits. Laboratory tests of blood count and serum biochemistry, urinalysis, culture, urinary antibiogram, and abdominal ultrasound were performed. The ultrasound image suggested a neoplastic urethral process. Because of the suspicion of neoplasm, a thoracic X-ray was performed, showing no evidence of metastasis. Computed tomography (CT) of the abdominal region was performed, revealing an expansive lesion in the urethra with loss of definition of the walls and urethral lumen extending to the level of the pelvic floor, measuring about 2.9 x 1.4 x 1.2 cm. After preanesthetic exams, the animal underwent resection and surgical anastomosis of the affected urethral region. The sectioned tissue was sent for histopathological analysis, with diagnosis of transitional cell carcinoma. Adjuvant chemotherapy was performed using carboplatin at a dose of 250 mg/m², intravenously, every 21 days for 6 sessions. After completing the protocol, abdominal ultrasonography was performed again, which showed a cicatricial process in the urethral region of the surgical excision, with no sign of tumor recurrence. A metronomic chemotherapy protocol was then started with cyclophosphamide at a dose of 15 mg/m², daily for 6 months, with periodic oncological follow-up. At the end of the period, the animal remained under periodic follow-up with ultrasound exams performed at 2-month intervals, and has been free from recurrence for 21 months until now. Discussion: Urethral neoplasms account for 0.5 - 2% of all canine tumors, and are represented mostly by transitional cell carcinomas. Clinical signs of urinary obstruction and hematuria are the most common, as reported in the patient in question. The definitive diagnosis is by histopathological examination. However, imaging tests such as computed tomography are important in the initial investigation and surgical planning. The indicated treatment is surgical resection of the mass with subsequent adjuvant chemotherapy or radiotherapy. The chemotherapy protocol associating cisplatin and piroxicam can achieve remission rates of 70%, but this association has a high nephrotoxic effect. In the present case, cisplatin was replaced by carboplatin in order to reduce the nephrotoxic effects of chemotherapy. The metronomic protocol using cyclophosphamide was used as maintenance therapy, at the end of the conventional chemotherapy protocol. Survival achieved was longer than that described in the literature in cases of transitional cell carcinomas in the urethral region. Therefore, multimodal therapy using surgery associated with conventional and metronomic chemotherapy, is an option in canines with urethral carcinoma.