Linfoma mediastinal em gato com vírus da leucemia felina / Mediastinal lymphoma in a cat with feline leukemia virus

Background: Mediastinal lymphoma occurs at a high incidence in cats positive for feline leukemia virus (FeLV). It is a malignant lymphocytic neoplasm that may trigger clinical signs such as dyspnea, apathy, regurgitation, and weight loss. The objective of this work is to report a case of mediastinal lymphoma associated with FeLV in a cat, and describe the clinical, pathological, diagnostic, and therapeutic aspects that can help the diagnosis and treatment of this disease. Case: A 3-year-old male neutered cat weighing 4.6 kg, positive for FeLV, and with a history of dyspnea and hyporexia was referred to a private veterinary clinic in the city of Caxias do Sul, RS, Brazil. The only alteration found at the clinical examination was a muffled sound during lung auscultation. Radiographs of the thorax revealed the presence of pleural effusion; after drainage of the fluid, a mass located in the mediastinal area became radiographically observable. An analysis of the effusion fluid showed high cellularity characterized by a markedly pleomorphic population of individual round cells consistent with lymphocytes. Small lymphocytes with a high nucleus:cytoplasm ratio, round nucleus, condensed chromatin, and inconspicuous nucleoli were observed, along with medium and large lymphocytes. The medium and large lymphocytes were characterized by a variably increased nucleus:cytoplasm ratio and a scant to moderate cytoplasm exhibiting moderate to intense basophilia and, occasionally, vacuoles. The nuclei were round, idented, or irregular; most of them were located eccentrically and contained coarse to finely granular chromatin. Nucleoli varied from single to multiple, round to angular, and central to peripheral and prominent. Macronucleoli and marked anisonucleosis were also observed, as well as binucleated cells and rare multinucleated cells. The conclusion was that it was a case of neoplastic effusion caused by a lymphoma. After an appointment with an oncologist, a chemotherapy protocol was established. The treatment of choice was CHOP, a combination of cyclophosphamide (20 mg/kg orally), doxorubicin (1 mg/kg intravenously), vincristine (0.5 mg/m2 intravenously), and prednisolone with a regressive dose starting at 2 mg/kg. The patient underwent 4 rounds of chemotherapy, and received a maintenance treatment thereafter. The patient's condition remained stable for 390 days without relevant clinical or hematological alterations. Discussion: The diagnosis of mediastinal lymphoma was established by associating clinical finings, laboratory exams, and radiographic findings. Exams of utmost importance to reach this diagnosis were the thoracic radiography, which revealed the presence of a mass in the thorax, and the cytopathological analysis of the effusion fluid, as round cell neoplasms are easily dissociated. Young cats are the group most affected by FeLV, and mediastinal lymphoma is considered the most prevalent type of lymphoma in this species. The most common clinical sign is dyspnea; however, other signs such as apathy, weight loss, regurgitation (due to pressure on the esophagus), and Horner's syndrome (owing to pressure on the thoracic sympathetic innervation) may also occur. This disease is treated with chemotherapy, with CHOP frequently used as the chemotherapeutic protocol. The good therapeutic response for a longer time than the average estimated by studies on the prognostic of this disease indicates that a correct diagnosis along with an assertive approach and the cooperation of the tutor are essential in cases of mediastinal lymphoma.

Penfigoide bolhoso em cão / Bullous pemphigoid in a dog

Background: In dogs, bullous pemphigoid (BP) is a subepithelial autoimmune disease, a rare dermatopathy in the clinicalroutine. BP is characterized by formation of vesicles and subepidermal blisters that result from dissolution of the dermalepithelial junction. Clinical signs of BP usually include severe dermatological alterations with a variable prognosis. Theaim of this work is to report a case of BP in a dog to contribute information for diagnosis, and to present clinical andpathological aspects that emerge during development of BP.Case: An adult male mongrel dog exhibited hyperemic, exudative, crusty lesions on the lip commissure and periocularareas. Results from laboratory tests were normal. Results from parasitological and mycological tests on skin scrapingswere negative. Imprint cytology of the crusts revealed presence of gram-positive cocci bacteria. In the histopathologicalanalysis of punch biopsy material, the epidermis was detached from the dermis, leading to formation of vesicles. Therewere inflammatory infiltrates containing neutrophils, eosinophils, and high amounts of fibrin, and areas of multifocalorthokeratotic hyperkeratosis. Multifocal infiltrates containing lymphocytes, histiocytes, and plasma cells were observedon the superficial portions of the dermis, which indicated a diagnosis of BP. After the definitive clinical diagnosis, theanimal was treated with enrofloxacin (Baytril Flavour®; 5 mg/kg once a day for 10 days), and prednisolone (Prediderm®;2 mg/kg once a day until further instructions). On the follow-up visit, 15 days later, the clinical picture had improved, andthe lesions had decreased. Continuity of the treatment was prescribed, along with a gradual decrease in the corticoid dose.The dose of prednisolone was initially reduced to 1 mg/kg once a day, and later to 0.5 mg/kg until improvement of theclinical status of the patient. Remission of the lesions was observed 13 weeks later...

Penfigoide bolhoso em cão / Bullous pemphigoid in a dog

Background: In dogs, bullous pemphigoid (BP) is a subepithelial autoimmune disease, a rare dermatopathy in the clinicalroutine. BP is characterized by formation of vesicles and subepidermal blisters that result from dissolution of the dermalepithelial junction. Clinical signs of BP usually include severe dermatological alterations with a variable prognosis. Theaim of this work is to report a case of BP in a dog to contribute information for diagnosis, and to present clinical andpathological aspects that emerge during development of BP.Case: An adult male mongrel dog exhibited hyperemic, exudative, crusty lesions on the lip commissure and periocularareas. Results from laboratory tests were normal. Results from parasitological and mycological tests on skin scrapingswere negative. Imprint cytology of the crusts revealed presence of gram-positive cocci bacteria. In the histopathologicalanalysis of punch biopsy material, the epidermis was detached from the dermis, leading to formation of vesicles. Therewere inflammatory infiltrates containing neutrophils, eosinophils, and high amounts of fibrin, and areas of multifocalorthokeratotic hyperkeratosis. Multifocal infiltrates containing lymphocytes, histiocytes, and plasma cells were observedon the superficial portions of the dermis, which indicated a diagnosis of BP. After the definitive clinical diagnosis, theanimal was treated with enrofloxacin (Baytril Flavour®; 5 mg/kg once a day for 10 days), and prednisolone (Prediderm®;2 mg/kg once a day until further instructions). On the follow-up visit, 15 days later, the clinical picture had improved, andthe lesions had decreased. Continuity of the treatment was prescribed, along with a gradual decrease in the corticoid dose.The dose of prednisolone was initially reduced to 1 mg/kg once a day, and later to 0.5 mg/kg until improvement of theclinical status of the patient. Remission of the lesions was observed 13 weeks later...(AU)