Metastatic Liposarcoma in a South African Fur Seal (Arctocephalus pusillus).
A 14-year-old female South African fur seal (Arctocephalus pusillus) was presented with a large skin mass on the right shoulder. At necropsy examination, multiple white nodules were found in the lungs, liver, spleen and right axillary lymph nodes. Histologically, the skin mass was composed of round to polygonal neoplastic cells with round to oval nuclei and variably sized cytoplasmic vacuoles. Cellular and nuclear atypia were prominent. Immunohistochemically, the neoplastic cells expressed vimentin, but not cytokeratins, S100 protein, adipophilin or desmin. The cytoplasmic lipid droplets stained positively with oil red O. Metastasis was seen in the lungs, liver, spleen and right axillary lymph nodes, with similar morphological features to the skin mass. Based on these findings, a diagnosis of a pleomorphic liposarcoma with systemic metastasis was made. No previous reports of metastatic liposarcomas have been published in marine mammals.
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, Japan.
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Pervin
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, Japan. Electronic address: izawa@vet.osakafu-u.ac.jp.
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Izawa
Adventure World, 2399 Nishimuro-gun, Shirahama-cho, Katada, Wakayama, Japan.
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Ito
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, Japan.
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Kuwamura
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, Japan. Electronic address: izawa@vet.osakafu-u.ac.jp.
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Yamate
D000818:Animals; D005260:Female; D046069:Fur Seals; D008080:Liposarcoma / Q000662:veterinary*; D012983:Soft Tissue Neoplasms / Q000662:veterinary*
South African fur seal; metastasis; pleomorphic liposarcoma; skin