Abstract
A male mixed breed dog with unknown age (case 1) and 5-year-old female golden retriever (case 2) were admitted to the Department of Veterinary Pathology at College of Veterinary Medicine, Seoul National University after sudden death. At necropsy, stifle region of case 1 was replaced by coalescing firm tan nodules approximately 1-3 cm in diameter. Neoplastic nodules were also presented in the lung. In case 2, the spleen was enlarged 3-5 times its normal size and numerous firm tan nodules were noted in the kidney, pericardium, diaphragm and lymph nodes. Histopathologically, the neoplastic masses of case 1 consisted of plump spindle cells having abundant cytoplasm and indistinct cell borders that formed interlacing bundle. In case 2, the masses were consisted of round to polygonal cells with abundant eosinophilic cytoplasm and eccentric nuclei. Numerous multinucleated giant cells containing nuclei of various sizes were noted. Immunohistochemically, neoplastic cells of all two cases stained intensely with vimentin and lysozyme. Based on the gross and light microscopic findings together with immunohistochemistry, both cases were diagnosed as localized histiocytic sarcoma with pulmonary metastasis and disseminated histiocytic sarcoma, respectively.
