Pathological features of intrathoracic histiocytic sarcoma in an Amami spiny rat (Tokudaia osimensis)

• Published in: Journal of Veterinary Medical Science Vol. 86; no. 10; pp. 1076 - 1080
• Main Authors: KOJIMA, Kazuhiro, CHAMBERS, James K, YOSHIZAWA, Madoka, FUJIOKA, Koh, UCHIDA, Kazuyuki
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2024; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Animals; Animals, Zoo; Anorexia; Cytoplasm; E-cadherin; Fatal Outcome; Giant cells; histiocytic sarcoma; Histiocytic Sarcoma - pathology; Histiocytic Sarcoma - veterinary; Leukocytes (eosinophilic); Lymph nodes; Male; Metastases; Necropsy; Pleura; Rodent Diseases - pathology; Sarcoma; spiny rat; Thorax; Tokudaia osimensis; Tumors; Vimentin; Wildlife Science; histiocytic sarcoma; Tokudaia osimensis; spiny rat
• ISSN: 0916-7250; 1347-7439; 1347-7439
• DOI: 10.1292/jvms.24-0185

A 4-year 9-month-old Amami spiny rat reared in a zoo died following a history of anorexia, weight loss, and respiratory distress. At necropsy, neoplastic tissues were found along the pleura and adhered to the thoracic wall, heart, and lungs. Histologically, the tumor was composed of diffuse, patternless sheets of large round to polygonal neoplastic cells with abundant eosinophilic cytoplasm, and multinucleated giant cells were often present. Metastatic lesions were observed in the abdominal lymph nodes. Neoplastic cells were immunopositive for vimentin, Iba-1, and CD204, and negative for E-cadherin and S100. Based on these findings, the tumor was diagnosed as histiocytic sarcoma. Compression of the lungs by the tumor may have caused respiratory failure and led to death.