Histiocytic sarcoma of the nasal cavity in a horse

Thoracic and Abdominal Mesothelioma in an Older Horse in Lazio Region

Simple Summary

Mesothelioma in the equine species is poorly described in Italy. It is important to make an early and error-free diagnosis for a correct clinical approach, as well as to establish the triggering cause of this neoplasm. The etiology, most likely of an environmental nature, would reveal a valid biological indicator in the horse, far from urbanized centers.

Abstract

A Quarter Horse, a gelding aged 22, was subjected to a clinical examination for colic syndrome. During admission to the clinic, blood counts and ultrasound examination were performed. Ultrasound revealed abdominal masses and abundant accumulation of pleural (50 L) and abdominal fluid (100 L). Cytology was performed on the aspirated fluid. The patient was euthanized. The autopsy examination revealed abundant effusion and nodular masses on the peritoneum, omentum, lungs, heart, and mediastinum. A diagnosis of epithelioid mesothelioma was made via histopathology and confirmed with immunohistochemistry; it showed positive antibodies against cytokeratin (CK) and vimentin. Mesothelioma is a rare cancer in older horses. It is important to employ the correct differential diagnostics using the available methods, providing valid ante-mortem support to the clinical veterinarian and monitoring the territory using this species as a valid biological indicator.

Disseminated Haemophagocytic Histiocytic Sarcoma in an African Pygmy Hedgehog (Atelerix albiventris)

A 3-year-old intact male African pygmy hedgehog (Atelerix albiventris) was found dead shortly after clinical onset of screaming, aerophagia and lethargy. On gross examination, the spleen was dark red and friable, and the liver was markedly enlarged with a prominent lobular pattern and multiple white nodules. Histopathological examination of liver and spleen revealed dense infiltrates of highly pleomorphic neoplastic, round to polyhedral cells with overt erythrophagocytosis. Similar neoplastic cells were found in the sinuses of the abdominal lymph nodes and in blood vessels in the heart, lung, brain and kidneys. Immunolabelling for CD204 confirmed the histiocytic origin of the neoplastic cells. To our knowledge, this is the first report of a disseminated haemophagocytic histiocytic sarcoma in a hedgehog.

Histological and immunohistochemical features of histiocytic sarcoma in four domestic ferrets (Mustela putorius furo)

Four cases of histiocytic sarcoma in domestic ferrets (Mustela putorius furo) are described in the present study. Tumor samples obtained from the abdominal viscera, including the spleen, were submitted for histologic examination. Microscopically, poorly demarcated masses contained numerous round- to pleomorphic-shaped cells with coarsely vacuolated and eosinophilic cytoplasm. Bizarre, binucleated tumor cells and multinucleated giant tumor cells with low phagocytic activity were commonly observed. Immunohistochemically, tumor cells in all of the cases were positive for vimentin, human leukocyte antigen-DR, ionized calcium-binding adapter molecule-1, and lysozyme, but some of them lacked cluster of differentiation (CD)163 or CD208 expression. The survival time after surgical resection was 9 days to 5 months. Histiocytic sarcoma in the ferret is a rare, but highly aggressive, tumor commonly found in the spleen.