Intra-Abdominal Leiomyosarcoma in a Ferret (Mustela Putorius Furo): Histopathological and Immunohistochemical Characterization

Abstract

ABSTRACT. A 5 years old female ferret with an abdominal palpable mass confirmed at echo-graphic examination died during an explorative laparotomy. A single lymph-node-like nodule was found adjacent to the intestinal loops. The round mass well circumscribed, solid and white, histologically, at low magnification, appeared encapsulated and built up by a population of atypical spindle cells arranged in interwoven fascicles. The cells had high anisocytosis degree, moderate mitotic activity and prominent nucleoli. A central area of necrosis was present. To characterise the tumour immunohistochemically cytokeratin, vimentin, S-100, melan-A, vWF, desmin, actin and α-actin were applied. Neoplastic cells resulted positive to vimentin, actin and α-actin. Based on the histological and immunohistological pattern a diagnosis of leiomyosarcoma was made. KEY WORDS: abdomen, ferret, leiomyosarcoma.J. Vet. Med. Sci. 70(5): 513-515, 2008 In the last years there has been a remarkable increase in the number of documented neoplasms found in ferrets and among these soft tissue sarcomas are reported and characterized less frequently than carcinomas and round cell tumours [4,5]. Among the soft tissue tumors the muscular ones previously described include a large number of dermal leiomyosarcoma This short communication describes a case of intraabdominal leiomyosarcoma in a domestic pet ferret of undetermined origin.A 5 years old female ferret with lethargy, alopecia and hypothermia was conducted to veterinary examination: the ferret was depressed and had an abdominal palpable mass confirmed at echo-graphic examination. During an explorative laparotomy a single unattached nodule was found floating freely in the abdominal cavity adjacent the intestinal loops. Following the death of the animal, occurred during the surgery, the single lymph-node-like abdominal mass was identified, biopsied, fixed in 10 per cent neutral-buffered formalin and sent to the Histopathology laboratory of Istituto Zooprofilattico Sperimentale of Torino.At macroscopic examination the mass was 1 cm in diameter and appeared round, well-demarcated, solid and white.The tissue was trimmed, routinely processed, embedded in paraffin wax, sectioned at 3-5 µm and stained with haematoxylin and eosin (HE) and histochemically with Mas-

Testicular leiomyosarcoma and marked alopecia in a cryptorchid ferret (Mustela putorius furo)

“…This raises the question, whether these tumours could have the potential to secrete hormones, leading to the described clinical signs in ferrets. Unfortunately, the primary site of the intra-abdominal tumour could not be determined and hormone levels were not stated by the authors (17).…”

“…Instead, an inguinal mass representing a neoplastic cryptorchid tesicle was found. The microscopic and immunohistochemical findings, such as positive reaction for α-SMA and desmin and negative cytokeratin labeling, indicated that the neoplastic cells were of smooth muscle origin (1,7,12,17). This led to the diagnosis of a multilobular, partly infiltrating testicular leiomyosarcoma with compression of pre-existing tissue, interstitial cell hyperplasia, and marked reactive proliferation of collagen-rich fibrous tissue.…”

“…Interestingly, alopecia was also a clinical finding in a case of intra-abdominal leiomyosarcoma of a female ferret (17). This raises the question, whether these tumours could have the potential to secrete hormones, leading to the described clinical signs in ferrets.…”

A KIT-Positive Gastrointestinal Stromal Tumor in a Ferret (Mustela Putovius Furo)

“…8 Recently, another intraabdominal leiomyosarcoma was reported and probably was of intestinal origin. 11 However, KIT immunolabeling was not performed to differentiate GISTs from other mesenchymal neoplasms in these earlier reports. In human medicine, definitive diagnosis of GIST requires positive immunolabeling of tumor cells for KIT, as recommended by the National Institutes of Health (NIH) Consensus Conference.…”

“…Only 2 of the neoplasms were of mesenchymal origin; 1 was a leiomyoma of the cecum and 1 a leiomyosarcoma of the rectum 8 . Recently, another intra-abdominal leiomyosarcoma was reported and probably was of intestinal origin 11 . However, KIT immunolabeling was not performed to differentiate GISTs from other mesenchymal neoplasms in these earlier reports.…”