Tumor ósseo multilobular em um cão / Multilobular tumor of bone in a dog

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called ofmany names for a long time, as: chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobularchondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could becorrelated with humans’ tumors. This tumor is observed specially in skull bone, although it was reported in zygomaticarc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signsdepending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth ofMTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumorhas low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describeanatomopathological changes.Case: A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. Thepatient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull,which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firmconsistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas.The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolatedmesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleolithat was involved by eosinophilic extracellular matrix...

Tumor ósseo multilobular em um cão / Multilobular tumor of bone in a dog

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called ofmany names for a long time, as: chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobularchondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could becorrelated with humans tumors. This tumor is observed specially in skull bone, although it was reported in zygomaticarc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signsdepending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth ofMTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumorhas low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describeanatomopathological changes.Case: A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. Thepatient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull,which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firmconsistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas.The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolatedmesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleolithat was involved by eosinophilic extracellular matrix...(AU)

Timoma canino associado à miastenia gravis / Canine thymoma associated to myasthenia gravis

Background: Thymomas are epithelial neoplasms of the thymus, although lymphocyte infiltration is common. Histological features are not sufficient to define its biological behaviour, which is dependent of clinical criteria of invasiveness and resectability. Myasthenia gravis may happen as a paraneoplastic syndrome in up to 47% of canine thymomas. This article aims at reporting a case of thymoma associated with myasthenia gravis in a dog, emphasizing the morphological, phenotypical and therapeutical aspects.Case: A 7-year-old, male Labrador, was presented with a history of acute dyspnea and exercise intolerance. The physical examination revealed a “red-brick” mucousa, tachycardia and cardiac and pulmonar hypofonese. Chest radiographs revealed an area of increased radiopacity in the cranial mediastinum without a plane of separation to the heart. The eccodopplercardiogram exam identified a poorly delimited mass adjacent to the base of the heart, measuring 9.5x6.8cm. Computed tomography demonstrated it as an expansive neoformation (9.5x6.5x7.8cm). Mass was removed through intercostal thoracotomy and the removed tissue was submitted to histopathology with a diagnosis compatible with type AB thymoma (mixed). Immunohistochemistry was positive for AE1/AE3 citokeratin in 90% of epithelial cells, confirming tumour origin. Tumour infiltrating lymphocytes were positive for CD79a (70%) and CD3 (20%). The proliferation index (Ki-67 imunolabeling) was 60%. About 45 days after surgery the patient was presented with generalized muscle weakness and regurgitation, with confirmed megaesophagus on chest X-ray. Treatment with pyridostigmine was initiated because of suspected myasthenia gravis, and complete remission of the neurological signs occurred within a month. A chemotherapeutic protocol with carboplatin was then instituted. After four sessions, a new thoracic radiograph revealed tumour recurrence in the cranial mediastinum.[...]

Timoma canino associado à miastenia gravis / Canine thymoma associated to myasthenia gravis

Background: Thymomas are epithelial neoplasms of the thymus, although lymphocyte infiltration is common. Histological features are not sufficient to define its biological behaviour, which is dependent of clinical criteria of invasiveness and resectability. Myasthenia gravis may happen as a paraneoplastic syndrome in up to 47% of canine thymomas. This article aims at reporting a case of thymoma associated with myasthenia gravis in a dog, emphasizing the morphological, phenotypical and therapeutical aspects.Case: A 7-year-old, male Labrador, was presented with a history of acute dyspnea and exercise intolerance. The physical examination revealed a “red-brick” mucousa, tachycardia and cardiac and pulmonar hypofonese. Chest radiographs revealed an area of increased radiopacity in the cranial mediastinum without a plane of separation to the heart. The eccodopplercardiogram exam identified a poorly delimited mass adjacent to the base of the heart, measuring 9.5x6.8cm. Computed tomography demonstrated it as an expansive neoformation (9.5x6.5x7.8cm). Mass was removed through intercostal thoracotomy and the removed tissue was submitted to histopathology with a diagnosis compatible with type AB thymoma (mixed). Immunohistochemistry was positive for AE1/AE3 citokeratin in 90% of epithelial cells, confirming tumour origin. Tumour infiltrating lymphocytes were positive for CD79a (70%) and CD3 (20%). The proliferation index (Ki-67 imunolabeling) was 60%. About 45 days after surgery the patient was presented with generalized muscle weakness and regurgitation, with confirmed megaesophagus on chest X-ray. Treatment with pyridostigmine was initiated because of suspected myasthenia gravis, and complete remission of the neurological signs occurred within a month. A chemotherapeutic protocol with carboplatin was then instituted. After four sessions, a new thoracic radiograph revealed tumour recurrence in the cranial mediastinum.[...](AU)

Mammary fibroadenomatoid hyperplasia in a heifer / Hiperplasia fibroadenomatoide mamária em uma novilha

This manuscript described the anatomopathological and immunohistochemical findings in a rare case of mammary fibroadenomatoid hyperplasia in a 12-month-old Holstein heifer. A yellow, multilobulated, firm 20cm x 9cm x 6.5cm mass affecting the right quarters of the udder was observed. Total mastectomy was performed. Microscopic evaluation revealed severe hyperplasia of the mammary epithelium and numerous well-differentiated and mildly pleomorphic acini. Additionally, moderate proliferation of the fibrous connective tissue and the myoepithelial cells near the proliferating acini was evident. About 50% of the proliferating epithelial cells showed positive nuclear labeling for estrogen and progesterone receptors, and approximately one-third were positive for Ki-67. In addition, the myoepithelial cells exhibited diffuse nuclear immunoreactivity for p63. Based on the clinical, morphologic, and immunohistochemical findings, a diagnosis of mammary fibroadenomatoid hyperplasia with probable influence of ovarian steroids was made.

Este artigo descreve os achados anatomopatológicos e imuno-histoquímicos de um caso raro de hiperplasia fibroadenomatoide mamária em uma novilha Holandesa de 12 meses. Observou-se uma massa amarelada, firme, multilobulada, medindo 20 x 9 x 6,5 cm e afetando os quartos direitos do úbere. Mastectomia total foi realizada. Microscopicamente, notou-se hiperplasia acentuada do epitélio mamário e numerosos ácinos levemente pleomórficos e bem diferenciados. Proliferação moderada do tecido conjuntivo fibroso e das células mioepiteliais próximos aos ácinos proliferados era também evidente. Aproximadamente 50% das células epiteliais proliferadas mostraram marcação nuclear positiva para receptores de estrógeno e progesterona e cerca de um terço dessas células era positivo para Ki-67. Além disso, as células mioepiteliais exibiram reação nuclear e difusa para p63. Com base nos achados clínicos, morfológicos e imuno-histoquímicos, firmou-se o diagnóstico de hiperplasia fibroadenomatoide mamária com provável influência de esteroides ovarianos.

Mammary fibroadenomatoid hyperplasia in a heifer / Hiperplasia fibroadenomatoide mamária em uma novilha

This manuscript described the anatomopathological and immunohistochemical findings in a rare case of mammary fibroadenomatoid hyperplasia in a 12-month-old Holstein heifer. A yellow, multilobulated, firm 20cm x 9cm x 6.5cm mass affecting the right quarters of the udder was observed. Total mastectomy was performed. Microscopic evaluation revealed severe hyperplasia of the mammary epithelium and numerous well-differentiated and mildly pleomorphic acini. Additionally, moderate proliferation of the fibrous connective tissue and the myoepithelial cells near the proliferating acini was evident. About 50% of the proliferating epithelial cells showed positive nuclear labeling for estrogen and progesterone receptors, and approximately one-third were positive for Ki-67. In addition, the myoepithelial cells exhibited diffuse nuclear immunoreactivity for p63. Based on the clinical, morphologic, and immunohistochemical findings, a diagnosis of mammary fibroadenomatoid hyperplasia with probable influence of ovarian steroids was made.(AU)

Este artigo descreve os achados anatomopatológicos e imuno-histoquímicos de um caso raro de hiperplasia fibroadenomatoide mamária em uma novilha Holandesa de 12 meses. Observou-se uma massa amarelada, firme, multilobulada, medindo 20 x 9 x 6,5 cm e afetando os quartos direitos do úbere. Mastectomia total foi realizada. Microscopicamente, notou-se hiperplasia acentuada do epitélio mamário e numerosos ácinos levemente pleomórficos e bem diferenciados. Proliferação moderada do tecido conjuntivo fibroso e das células mioepiteliais próximos aos ácinos proliferados era também evidente. Aproximadamente 50% das células epiteliais proliferadas mostraram marcação nuclear positiva para receptores de estrógeno e progesterona e cerca de um terço dessas células era positivo para Ki-67. Além disso, as células mioepiteliais exibiram reação nuclear e difusa para p63. Com base nos achados clínicos, morfológicos e imuno-histoquímicos, firmou-se o diagnóstico de hiperplasia fibroadenomatoide mamária com provável influência de esteroides ovarianos.(AU)