Management of tendon haemangiosarcoma in a Bactrian camel (Camelus bactrianus) – a case report

An 18-year old intact female Bactrian camel (Camelus bactrianus) was suffering from lameness due to a mass on the right dorsal metacarpal region that caused acute swelling and local skin necrosis. Histology examination and immunohistochemistry of the biopsy material of a mass revealed haemangiosarcoma of the extensor tendons. Three weeks after the biopsy, the tumour was enlarged to 6 cm in diameter and the animal became disabled. The tumour with its associated tendon were resected and the tendon’s edges were bridged with a synthetic polytape graft. The camel was fully weight-bearing after the surgery. Two weeks later, the graft was removed due to widespread necrosis. Since the wound was positive for Corynebacterium sp., Acinetobacter iwoffii, Micrococcus sp., Escherichia coli, and Staphylococcus sp., the post-operative antibiotic treatment was prolonged for 28 days. Four months later, the wound healed using daily irrigation and bandaging and the camel walked normally. Nine months after diagnosis, the camel suddenly died without any clinical signs. Metastases of the haemangiosarcoma were found in the liver, lungs, kidneys, brain, meninges, and mediastinum. Exsanguination due to rupture of a liver metastasis was determined as the cause of the death. Haemangiosarcoma is a malignant neoplasm that arises from endothelial cells of blood vessels and tends to be very aggressive. To the author’s knowledge, this is the first case report of a metastasizing haemangiosarcoma arising from the lateral extensor tendon in a Bactrian camel. Camelids, polytape graft, metastases, neoplasia, tendon surgery There are only few reports on neoplasia in Old World camelids compared to llamas or alpacas (Effron et al. 1977; Valentine and Martin 2007; Molenaar et al. 2009). In Bactrian camels (Camelus bactrianus), metastasing gastric adenocarcinoma, histiocytic sarcoma, meningioma, and a vaginal leiomyoma have been reported to date (Molenaar et al. 2009). In the Arabian dromedary (Camelus dromedarius), an ovarian teratoma, bronchoalveolar adenocarcinoma, lymphatic leukaemia, renal cell carcinoma, ulnar osteosarcoma, pulmonary leiomyoma, squamous cell carcinoma, fibroma, lipoma, and fibromyxosarcoma have been described (Molenaar et al. 2009; Fahd and Yasmin 2013; Gamal and Shawky 2013). To our knowledge, neoplasia involving the tendons has not been reported in camelids yet. Materials and Methods An 18-year old female Bactrian camel from ZOO Ljubljana was examined due to the lameness of the right thoracic limb. The animal suffered from a solid movable circular mass (measuring 4 cm in diameter) without ulcerations on the right dorsal metacarpal region. The camel was put under general anaesthesia during incisional biopsy of the lesion. It was determined that the mass was in contact with the extensor tendon and seemed to be ACTA VET. BRNO 2017, 86: 97–100; https://doi.org/10.2754/avb201786010097 Address for correspondence: Doc. MVDr. Eva Bártová, Ph.D. Department of Biology and Wildlife Diseases Faculty of Veterinary Hygiene and Ecology University of Veterinary and Pharmaceutical Sciences Brno Palackého tř. 1946/1, Brno 612 42, Czech Republic Phone: +420 541 562 633 E-mail: [email protected] http://actavet.vfu.cz/ growing around the tendon. Biopsy material was fixed in 10% buffered formalin, embedded in paraffin, sectioned at 4 μm, and stained with haematoxylin and eosin. Histology examination revealed a poorly demarcated, unencapsulated neoplastic mass, composed of infiltrative, pleomorphic, spindle, ovoid or oval shaped, anisocytotic neoplastic cells with prominent nucleoli, which formed irregular blood-filled clefts, channels and cavities. Bior even multinucleated cells were seen. Eighteen mitotic figures were counted per 10 high power fields. Large, multifocal areas of haemorrhage and necrosis with neutrophil infiltration were scattered throughout the tumour. Immunohistochemical assay was done using the mouse monoclonal anti-von Willebrand factor antibody (DAKO, Denmark) for the immunolabelling of antigen. The sections of specimen were incubated with primary antibodies for one hour at room temperature in a humid chamber. Peroxidase activity was stopped with Peroxidase-Blocking Solution (DAKO, Denmark) for 30 min at room temperature. Subsequently, visualization kit (DAKO REALTM EnVisionTM Detection System Peroxidase/DAB+, Rabbit/Mouse, Denmark) was used according to the manufacturer’s instructions. Slides were counterstained with Mayer’s haematoxylin and mounted. Positive (normal endothelium) and negative (incubation with antibody diluent (DAKO Denmark) without the primary antibody) controls were included. Neoplastic endothelial cells were diffusely and strongly positive for von Willebrand factor (Plate VI, Fig.. 1). Based on histopathological and immunohistochemical findings, the tumour was diagnosed as haemangiosarcoma.