Anatomopathological aspects of cutaneous pleomorphic liposarcoma with muscular involvement - case report in a dog

ABSTRACT Given the rare occurrence, and malignant and invasive nature of pleomorphic liposarcoma and the scarcity of scientific descriptions in dogs, the objective of this study was to discuss the anatomopathological aspects of this neoplastic subtype through a case report. A Dachshund, male, 13 years old, was presented one year ago with a significant increase in skin volume in the left lateral and lumbar region, which was rounded, progressive, non-adherent, and firm. Chest x-rays did not show lung metastases, and the sites indicated an increase in soft tissue density volume with involvement of muscles. Ultrasound did not detect abdominopelvic metastases and suggested a cavitary pattern of the nodule. Surgical excision with a wide safety margin, followed by removal of part of the muscular fascia, was performed. Macroscopically, the nodule was infiltrative, brownish with irregular whitish areas, soft and heterogeneous and microscopy revealed malignant neoplasm of adipocytes with a solid arrangement formed by epithelioid cells accompanied by moderate lipoblasts, in addition to cells characterized by well-defined eosinophilic cytoplasm, to a lesser extent vacuolated. It is possible to infer that, despite being invasive and infiltrative, pleomorphic liposarcoma did not cause metastases and with surgical removal, there was no recurrence, which favored the patient's quality of life and survival.