Round Cell Variant of Myxoid Liposarcoma in a Japanese Macaque (Macaca fuscata)

Abstract

Abstract.A 5-year-old, female, Japanese Macaque (Macaca fuscata) was diagnosed with round cell variant of myxoid liposarcoma. At necropsy, multifocal to coalescing, reddish tan to white nodules, ranging from 0.5 to 1 cm in diameter, were noted throughout the omentum and retroperitoneum. Similar neoplastic nodules were also present in diaphragm, abdominal wall, and on hepatic capsule. Microscopically, neoplastic masses consisted of round to polyhedral cells, which had round, often eccentric nuclei and abundant eosinophilic granular and microvacuolated cytoplasm; Oil red O staining demonstrated large numbers of lipid droplets in the cytoplasm. Ultrastructurally, the cytoplasm of the tumor cells was packed with occasional lipid vacuoles and numerous enlarged mitochondria. Immunohistochemistry revealed tumor cells were positive for vimentin, while negative to cytokeratin, actin, and Factor VIII-related antigen. To the authors' knowledge, this is the first report of round-cell variant of myxoid liposarcoma in nonhuman primate.

Cytologic, histologic, and immunohistochemical features of lingual liposarcoma in a dog

“…Round to polygonal cells with lightly eosinophilic and finely granular cytoplasm were observed in pleomorphic liposarcomas in dogs, 9 and in a Japanese macaque with a myxoid liposarcoma the cells had abundant eosinophilic granular or microvacuolated cytoplasm. 21 Similar cells have been also observed in a disseminated liposarcoma in a dog, classified as round cell liposarcoma, although loose fibrous or myxoid tissue was detected histologically. 7 In the dog reported here, the predominance of large cells with a single vacuole or multiple clear vacuoles and rare sheets of round eosinophilic granular cytoplasm in the tissue sections, with no evidence of myxoid material or bizzares cells, suggested well-differentiated liposarcoma with eosinophilic granular cells.…”

Spontaneous retroperitoneal liposarcoma in a free‐ranging juvenile golden‐headed lion tamarin (Leontopithecus chrysomelas)

“…7 Conversely, there are only few reported liposarcoma cases. These include subcutaneous liposarcoma in a geriatric bonnet macaque (Macaca radiata), 8 abdominal round-cell variant myxoid liposarcoma in a juvenile Japanese macaque (M. fuscata), 9 intercostal liposarcoma in an adult yellow baboon (Papio cynocephalus anubis), 2 and myeloliposarcomas in pottos (Perodicticus potto). 10,11 Herein, we report a retroperitoneal liposarcoma in a freeranging golden-headed lion tamarin (GHLT; Leontopithecus chrysomelas), representing the first case of such tumor subtype in NWPs.…”

“…Conversely, there are only few reported liposarcoma cases. These include subcutaneous liposarcoma in a geriatric bonnet macaque ( Macaca radiata ), abdominal round‐cell variant myxoid liposarcoma in a juvenile Japanese macaque ( M. fuscata ), intercostal liposarcoma in an adult yellow baboon ( Papio cynocephalus anubis ), and myeloliposarcomas in pottos ( Perodicticus potto ) …”

Pleomorphic Liposarcoma of the Intrathoracic Cavity in a Meerkat (Suricata suricatta)

“…Liposarcomas are rare neoplasms in domestic animals, but have been reported to occur in many species [1,4,5,[7][8][9][11][12][13]. In Herpestidae animals, the neoplasms have seldom been reported and, to our knowledge, their occurrence has not been documented for meerkats so far [10].…”

“…The tumor was diagnosed as liposarcoma on the basis of the following findings: (1) the cytoplasm had numerous small vacuoles, which were identified as lipid droplets with Oil red O staining [5,6]; (2) fine argentaffin fibrils encircled individual neoplastic cells [8]; (3) ultrastructurally, the neoplastic cells had several lipid droplets without limiting membranes [4,7,8,12]. Based on the gross and microscopic findings, and the result of immunohistochemistry and electron microscopy, the tumor was diagnosed as a pleomorphic liposarcoma arising from the thoracic cavity with systemic metastasis.…”