Adenoma of the uterine tube in the bitch: Two case reports

Epithelial and mesenchymal tumours of the uterine tube are unusual in animals. In a nulliparous, German shepherd, 4-year-old bitch, a pedunculated hemorrhagic neoplasm was found connected to the fimbriated end of the left uterine tube. It showed a papillary growth pattern with branched processes of fibromuscular stroma lined by tall columnar epithelium, resembling the tubal epithelium. A nulliparous, mixed breed, 10-year-old bitch was referred for an abdominal enlargement, lethargy, anorexia, dyspnoea, hypothermia and dehydration. Abdominal palpation and ultrasonography revealed a large abdominal mass, with a unilocular cystic appearance. The mass completely replaced the ovarian bursa, but not the ovary, was of 30 cm in diameter, with a smooth, dark red, surface. At section, the inner surface was irregular because of an abundance of reddish-brown papilliferous projections. Histologically, the mucosal and submucosal layers were organized in irregularly branched papillae with a fibromuscolar core, lined by a columnar epithelium, including tall ciliated and non-ciliated secretory cells. Immunohistochemically, in both cases, the neoplastic epithelia showed moderate cell reaction for vimentin and cytokeratins, while the neoplastic stroma strongly expressed vimentin and smooth muscle actin. Two uterine tube adenomas were diagnosed.