Extraskeletal chondrosarcoma in the tongue of a dog: case report and retrospective analysis of 236 tongue masses (2011-2019).

Chondrosarcomas are common tumors of the canine appendicular and axial skeleton; however, extraskeletal chondrosarcomas are very rare. Herein we report a case of extraskeletal chondrosarcoma in the tongue of a dog. Histologically, glossal skeletal muscle was infiltrated and effaced by islands of cartilage and streams of spindle-shaped cells. Retrospective analysis of 236 tongue masses submitted to the Iowa State University surgical biopsy service between 2011 and 2019 showed that the majority of submitted tongue masses are either non-neoplastic or benign, with granular cell tumors identified as the most prevalent benign neoplasms. Malignant tumors accounted for nearly 30% of all submitted masses, with malignant melanoma diagnosed most frequently.

Evaluation of adjuvant chemotherapy in feline injection site-associated sarcoma / Avaliação da quimioterapia no tratamento do sarcoma de aplicação felino

Feline Injection Site-Associated Sarcoma (FISS) is a neoplasm that implies in reduction of quality of life and overall survival in feline patients. A retrospective study of 13 cases of FISS was conducted to evaluate the efficacy of surgical treatment associated to chemotherapy with doxorubicin or carboplatin. Local recurrence occurred in all patients. Patients treated with surgery and chemotherapy presented a longer overall survival and disease-free interval when compared to those that solely received surgical treatment, although no statistical significance was observed (p= 0.3360 and 0.7506, respectively). Surgery remains as the main option for FISS treatment. Further prospective studies with larger samples are warranted to investigate the benefit of chemotherapy for this neoplasm.(AU)

O Sarcoma de Aplicação Felino (SAF) é uma neoplasia associada a redução na qualidade de vida e sobrevida global. O objetivo deste estudo foi avaliar a eficácia da quimioterapia associada à cirurgia no manejo do SAF. Estudo retrospectivo de 13 pacientes com SAF submetidos à cirurgia isolada ou associada a quimioterapia com carboplatina ou doxorrubicina. Recorrência local ocorreu em todos os pacientes. Pacientes tratados com cirurgia e quimioterapia apresentaram maior sobrevida global e intervalo livre de doença quando comparados àqueles que receberam apenas tratamento cirúrgico, mas não foi observada diferença estatística (p=0,3360 e 0,7506, respectivamente). A cirurgia continua sendo a principal opção para o tratamento do SAF. Estudos prospectivos são necessários para investigação do real benefício da quimioterapia para esta neoplasia.(AU)

Extraskeletal myxoid chondrosarcoma with systemic metastasis in a five-month-old Irish setter dog.

Extraskeletal myxoid chondrosarcoma was found in a five-month-old male Irish setter dog. At necropsy, the largest mass, measuring 15 × 13 × 13 cm, was found in the right caudal lobe of the lung, and metastatic small masses were observed in multiple organs. Microscopically, the tumor comprised mainly atypical mesenchymal cells and myxoid stroma, which stained positively with Alcian blue. Immunohistochemically, the tumor cells stained positively for vimentin, S-100 protein, neuron-specific enolase, calretinin, and chromogranin A. Ultrastructurally, the cytoplasm of the tumor cells was comprised abundant rough endoplasmic reticulum, mitochondria, Golgi complex, free ribosomes and short irregular microvillous processes extending from the cytoplasm. Based on these pathological findings, this tumor was diagnosed as extraskeletal myxoid chondrosarcoma.

Malignant fibrous histiocytoma of the deep peri-articular tissue of the stifle in a dog.

A Belgian shepherd dog aged 4 years and 9 months was presented with acute onset of non-weight bearing lameness and stifle effusion of the left hind limb, caused by the deep form of a malignant fibrous histiocytoma originating in the deep musculature and fascia surrounding the stifle joint. The tumour progressed rapidly in the tissues along the femoral diaphysis with marked periosteal new bone formation. Cytology of a stifle joint aspirate revealed numerous large polygonal neoplastic cells with considerable anisocytosis and anisokaryosis. These cells were present in clusters, with cytoplasmic projections between the cells, but occasionally also occurred singly. Several cells contained multiple cytoplasmic vacuoles and occasional giant cells were also encountered. Adequate tumour-free margins were not possible with radical limb amputation and the dog was euthanased. Macroscopically the tumour appeared as an extensive pale tan, firm mass with scattered small haemorrhages and foci of yellow discolouration. Histologically the tumour consisted of dense neoplastic expanses or multiple nodules, composed of spindle-shaped fibroblastic cells, polygonal histiocytic cells or cell clusters and scattered giant cells with 2-3 nuclei. The polygonal neoplastic cells were frequently present around and invading lymphatics and blood vessels, causing neoplastic emboli. This is the 1st report of the clinical behaviour, radiography and cytology of the deep form of malignant fibrous histiocytoma in the dog.