A 15-year-old female, indoor, spayed, domestic shorthair cat was presented for post-mortem evaluation with a history of sudden death. A red-brown 3 cm x 4 cm neoplastic mass was identified within the body of the pancreas, along with multiple similar nodular structures within the omentum and liver. Associated lesions included hemoperitoneum, yellow discoloration of the peritoneal wall, and severe anemia. Spindle-shaped neoplastic cells exhibiting malignancy features, which occasionally contained within the cytoplasm haematoidin crystals and/or red blood cells, were observed during cytological examination. Histologically, the neoplastic cells were organized in short streams forming vascular spaces filled with erythrocytes. Immunohistochemically, the neoplastic cells were immunolabeled for vimentin and CD31, supporting the diagnosis of hemangiosarcoma. This report offers a complete post-mortem and histological evaluation of a rare tumor in cats with an unusual location and a comparative assessment of 3 anti-CD31 antibodies.

This study aimed to describe the gross and histological features of multiple endocrine and non-endocrine neoplasia, including multiple PGLs found in two Boxer dogs. Additionally, the identified PGLs were immunohistochemically evaluated, and the subunits 2, 3, and 4 of the SDHD gene were screened for possible mutations. The tumors identified include aortic and carotid body PGLs, thyroid follicular-compact carcinoma, and subcutaneous lipomas. One case also had a Leydig cell tumor and adrenal cortex hyperplasia, while the other had H-type pancreatic carcinoma. Three out of 4 PGLs appeared benign, but one aortic body tumor showed malignant features with neoplastic emboli at its edge. Immunohistochemical analysis confirmed the neuroendocrine origin of all PGLs, with positive staining for Chromogranin A, NSE, and variable positivity for S100. No somatic mutations were found in exons 2, 3, and 4 of the SDHD gene in any of the evaluated PGLs. The absence of mutations in the evaluated SDHD gene subunits suggests the involvement of other genetic factors or pathways in the development of these tumors, warranting further investigation in this field.