Rapid diagnosis of tuberculosis in cattle reacting positive in antemortem assays is crucial in countries where eradication programs are operated to confirm the presence of the infection in tuberculosis-free herds. This study evaluated the accuracy of histopathologic examination by hematoxylin and eosin and Ziehl-Neelsen (ZN) staining applied in this framework, when suspected lesions are caused by low infectious doses and are detected in early stages of the disease. For this purpose, histologic methods were compared with mycobacterial culture as reference test on suspected lymph node samples from 173 cattle reacting positive in antemortem tests. Histopathology demonstrated high sensitivity (93.4%) and specificity (92.3%), while ZN sensitivity and specificity were respectively 33.9% and 100%. There was good agreement between histopathology and bacterial culture, suggesting that histopathologic examination is a reliable tool for rapid diagnosis in countries where active tuberculosis eradication programs allow the prompt identification and elimination of reactor cattle. Histopathology permits identification of typical mycobacterial lesions and its differentiation from other causes.

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-