RESUMO
An 8-year-old male rabbit (Oryctolagus cuniculus) presented with a subcutaneous mass in the proximal region of the fourth and accessory digit measuring 5.5 x 3.5 x 5.2cm. The mass was non-alopecic and exhibited irregular surface, ulceration and necrosis with predominantly pale and light brown coloring. Radiography revealed no involvement of bone and adjacent periosteum. The mass was marginally resected and the electrochemotherapy (ECT) was performed on the surgical bed. Histopathology and immunohistochemical analysis revealed positive reactions for Vimentin, Runx-2 and ki-67, leading to a diagnosis of extraskeletal osteosarcoma (ESOS). This report described a case of ESOS in a rabbit, thereby delineating its clinical presentation, anatomopathological characteristics, diagnostic modalities and recommended therapeutic interventions.
Um coelho macho de 8 anos (Oryctolagus cuniculus) apresentava uma massa subcutânea na região proximal do quarto e acessório dígitos medindo 5,5 x 3,5 x 5,2 cm. A massa não era alopécica e exibia superfície irregular, ulceração e necrose com coloração predominantemente pálida e marrom clara. A radiografia não revelou envolvimento de tecido ósseo ou periósteo adjacente. A massa foi submetida à excisão marginal e foi realizada eletroquimioterapia do leito cirúrgico. Histopatologia e análise imuno-histoquímica revelaram reações positivas para vimentina, Runx-2 e ki-67, levando ao diagnóstico de osteossarcoma extraesquelético. Este relato descreve um caso de osteossarcoma extraesquelético em um coelho, delineando sua apresentação clínica, características anatomopatológicas, modalidades diagnósticas e intervenções terapêuticas recomendadas.
RESUMO
Fibromatosis, or desmoid tumour, is characterized by excessive and infiltrative proliferation of connective tissue originating from aponeurotic muscle structures. Mammary fibromatosis is rare in humans and animals and its precise aetiology is unknown. A 10-year-old mixed-breed female dog developed a mass in the right cranial thoracic mammary gland (M1) and underwent lumpectomy. The mass was firm, with an irregular surface and distinct limits. Microscopically, it was a neoplastic proliferation of fusiform cells with low atypia, interspersed with abundant dense collagenous tissue, confirmed by histochemical staining with Gomori's trichrome and Masson's trichrome and immunopositivity for vimentin and smooth muscle actin, confirming mammary fibromatosis. Mammary fibromatosis in dogs needs further studies to elucidate its clinical, epidemiological and aetiopathogenic aspects.