This report describes the gross, histological, and immunohistochemical features of medullary thyroid carcinoma (MTC) with pulmonary metastases in a young dog. Sheets of pleomorphic cells supported by fibrous stroma characterized the primary mass, while metastatic nodules had a neuroendocrine pattern. Despite differing histologic features, all masses showed marked immunoreactivity against calcitonin and multiple neuroendocrine markers consistent with MTC. Although MTC is a well-recognized entity, it may be difficult to distinguish this mass from other thyroid neoplasms, necessitating immunohistochemical characterization.
Animals ; Carcinoma, Neuroendocrine/pathology/radiography/*veterinary ; Dog Diseases/*pathology/radiography ; Dogs ; Female ; Laryngeal Neoplasms/secondary/veterinary ; Lung Neoplasms/secondary/veterinary ; Neoplasm Metastasis ; Thyroid Neoplasms/pathology/radiography/*veterinary

An example of lymphoblastic lymphosarcoma was found in a 7-year-old male brown bear (Ursus arctos) that died after having a 7-month history of depression, anorexia and watery diarrhea. Grossly the mesenteric lymph nodes were enlarged to approximately 4 to 6 times their normal size and histologically diagnosed as lymphoblastic lymphosarcoma. The small intestinal mucosa was corrugated and had severe mural thickening due to infiltrated neoplastic cells. Hepatic metastasis was also noted. This is the first reported case of lymphosarcoma in Ursidae in Korea. As an incidental finding, endogenous lipid pneumonia was noted in the lung.
Animals ; Animals, Zoo ; Fatal Outcome ; Intestinal Mucosa/pathology ; Intestine, Small/pathology ; Korea ; Liver/pathology ; Liver Neoplasms/secondary/veterinary ; Lung/pathology ; Lymph Nodes/*pathology ; Male ; Mesentery ; Pneumonia, Lipid/pathology/veterinary ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis/pathology/*veterinary ; *Ursidae