Primary pulmonary chondrosarcoma in a bitch

Background: Primary lung neoplasms are uncommon in veterinary medicine, and when they develop, they are more frequently observed to be of epithelial origin. Although chondrosarcomas are the second most diagnosed type of neoplasm in dogs at skeletal sites, their development in extraskeletal tissues, including the spleen, aorta, heart, tongue, peritoneum, and lungs, corresponds to approximately only 1% of cases. Therefore, the occurrence of primary pulmonary chondrosarcoma is considered very rare in domestic animals. Considering the rare occurrence and scarcity of data regarding its development, the present report describes the clinical and pathological aspects of a case of primary pulmonary chondrosarcoma in a bitch. Case: A 8-year-old mixed-breed bitch, weighing 14.2 kg, was examined at one private veterinary clinic with the principal complaint of prolonged respiratory distress and resistance to exercise. Clinical evaluation revealed tachypnea with expiratory dyspnea due to intense pleural effusion, tachycardia, and diffusely pale mucous membranes. Thoracocentesis was performed with drainage of 1000 mL of modified transudate, and fluid cytology, blood count, and chest radiography were performed. Cytological analysis of the thoracic fluid did not identify neoplastic cells, the blood count showed intense regenerative anemia, and the radiograph showed an extensive area of consolidation in the left caudal lung lobe, compatible with neoplasia. The results of the tests performed, in addition to the evolution of the clinical picture and the impossibility of performing the indicated surgical intervention, culminated in the patient's unfavorable prognosis, followed by euthanasia, necropsy, and histopathological evaluation of the collected material. Necropsy revealed a white neoplastic formation with reddish areas and firm consistency that diffused into the parenchyma of the left caudal lung lobe with invasion of the rib cage, fracture of the fifth and sixth left ribs, diaphragmatic metastasis, intense hydrothorax, and moderate hydroperitoneum. Microscopically, in the histological sections of the lung and diaphragm, poorly differentiated mesenchymal cells with moderate anisocytosis and anisokaryosis and interspersed with them, moderately differentiated chondrocytes surrounded by chondroid matrix, moderate anisocytosis and anisokaryosis, and a low mitotic index culminated in the diagnosis of primary pulmonary mesenchymal chondrosarcoma. Discussion: Malignant epithelial neoplasms were suspected; however, the histopathological features observed were compatible with primary pulmonary chondrosarcoma. The characteristics of the fluid collected through thoracentesis led to its classification as a modified transudate, which is often associated with neoplastic and hemorrhagic processes; both alterations were present in this case. The diagnosis of primary pulmonary chondrosarcoma was established based on the histopathological findings since the cell type and distribution observed in the present case were compatible with the typical pattern observed in extraskeletal chondrosarcomas. An unfavorable prognosis is common in cases of primary or metastatic lung neoplasm since, in most cases, the condition is identified in the advanced stages of the disease, making therapeutic management challenging. Given the increase in the number of dog deaths due to neoplasms in recent years, this case report may contribute to a better understanding of the biological behavior of pulmonary chondrosarcoma and assist in the choice of treatment to be adopted when required.

Condrossarcoma mesenquimal extraesquelético em um gato: relato de caso / Extraskeletal mesenchymal chondrosarcoma in a cat: case report

Condrossarcoma mesenquimal extraesquelético (CME) é um neoplasma maligno e raro em animais domésticos. Descreve-se um caso de CME em uma gata que apresentava uma massa firme, branco-amarelada, medindo 18cm de diâmetro, aderida à musculatura do membro pélvico esquerdo. O exame citológico revelou presença de células fusiformes individualizadas pleomórficas e agregados de pequenas células ovais, sem bordas definidas em meio à matriz intercelular amorfa. Devido à impossibilidade de tratamento e ao prognóstico desfavorável, foi realizada eutanásia. Microscopicamente foram observadas células fusiformes indiferenciadas e agregados de células condroides pleomórficas. O diagnóstico de CME foi confirmado pelas técnicas de azul alciano, tricrômico de Masson e pela prova imunoistoquímica, utilizando-se anticorpos antivimentina.(AU)

Extraskeletal mesenchymal chondrosarcoma (EMC) is a rare malignant tumor in domestic animals. We described a case of EMC in a cat with a mass measuring 18cm in diameter, yellowish-white and firm attached to the muscles in left hind limb. Cytological examination revealed the presence of individual pleomorphic spindle cells and clusters of small oval cells with no hard edges in the midst of an amorphous intercellular matrix. Due to the impossibility of treatment and poor prognosis, the cat was euthanized. Microscopically undifferentiated spindle cells and clusters of pleomorphic chondroid cells were observed. The CME diagnosis was confirmed with thealcian blue, Masson's trichrome and immunohistochemistry techniques, using antivimentin antibodies.(AU)

Condrossarcoma mesenquimal de origem patelar em cão / Mesenchymal chondrosarcoma in dog originated from its patella

O presente relato descreve os achados clínico-patológicos de um condrossarcoma mesenquimal canino em um cão. Um cão macho, fila brasileiro de 13 anos de idade, mostrou, no físico, claudicação e aumento da massa tecidual do membro pélvico direito. Exame radiográfico tecidual foi realizada e revelou condroblastos neoplásicos. O proprietário decidiu não amputar o membro do animal e solicitou eutanásia. Completa necropsia e exame histológico foram realizados. A análise macroscópica mostrou proliferação tecidual neoplásica, originada da patela. Microscopicamente, a proliferação tecidual caracterizava-se pela coexistência de ilhas cartilaginosas, constituídas por células de variável maturidade e envoltas por células mesenquimais indiferenciadas. Este é o primeiro relato de condrossarcoma mesenquimal canino de origem patelar(AU)

The present report describes the clinicopathological findings of the mesenchymal chondrosarcoma in a dog. A 13-year-old male brazilian fila dog showed under physical examination, lameness and tissue mass increase of the right forelimb. Radiography revealed neoplasic chondroblasts. The owners decision was not th have dogs limb amputed and he required euthanasia. A complete necropsy and histological examinations was performed. The macroscopic examination showed neoplastic proliferations originated from the patella. Microscopically, the tissue proliferation was characterized by the coexistence of sharply demarcated cartilaginous islands of varied maturity and surrounding undifferentiated Mesenchymal cells. This is the first report of canine Mesenchymal chondrosacoma originated from the patella(AU)

Condrossarcoma mesenquimal de origem patelar em cão / Mesenchymal chondrosarcoma in dog originated from its patella

O presente relato descreve os achados clínico-patológicos de um condrossarcoma mesenquimal canino em um cão. Um cão macho, fila brasileiro de 13 anos de idade, mostrou, no físico, claudicação e aumento da massa tecidual do membro pélvico direito. Exame radiográfico tecidual foi realizada e revelou condroblastos neoplásicos. O proprietário decidiu não amputar o membro do animal e solicitou eutanásia. Completa necropsia e exame histológico foram realizados. A análise macroscópica mostrou proliferação tecidual neoplásica, originada da patela. Microscopicamente, a proliferação tecidual caracterizava-se pela coexistência de ilhas cartilaginosas, constituídas por células de variável maturidade e envoltas por células mesenquimais indiferenciadas. Este é o primeiro relato de condrossarcoma mesenquimal canino de origem patelar

The present report describes the clinicopathological findings of the mesenchymal chondrosarcoma in a dog. A 13-year-old male brazilian fila dog showed under physical examination, lameness and tissue mass increase of the right forelimb. Radiography revealed neoplasic chondroblasts. The owner’s decision was not th have dog’s limb amputed and he required euthanasia. A complete necropsy and histological examinations was performed. The macroscopic examination showed neoplastic proliferations originated from the patella. Microscopically, the tissue proliferation was characterized by the coexistence of sharply demarcated cartilaginous islands of varied maturity and surrounding undifferentiated Mesenchymal cells. This is the first report of canine Mesenchymal chondrosacoma originated from the patella