Disgerminoma bilateral e hiperplasia endometrial cística com piometra em cadela / Bilateral Dysgerminoma and Cystic Endometrial Hyperplasia with Pyometra in a Bitch

ABSTRACT

Background: Ovarian tumors are considered rare both in dogs and cats. Germ cell neoplasms correspond to approximately 15% of the cases and can be classified into dysgerminomas, teratomas and teratocarcinomas. Reports of bilateral dysgerminoma in dogs and cats are rare. The aim of this work was to describe a case of bilateral dysgerminoma and cystic endometrial hyperplasia with pyometra in a bitch by presenting the clinical, surgical, pathological and immunohistochemical findings. Case A 10-year-old female crossbred dog was presented with a history of vomiting, apathy and purulent vulvar discharge. Physical examination revealed hyperthermia and pain was observed on abdominal palpation. Ultrasound examination revealed cystic formation and increased echogenicity inside the uterus. The animal underwent ovariohysterectomy (OHE). Macroscopically, the ovaries were multinodular, spherical to ovoid in shape, measuring 6 cm in diameter, and with a dark red color; they exhibited a firm consistency and a hemorrhagic cut surface with cystic areas and foci of necrotic tissue. At microscopic evaluation of both ovaries, the neoplasm consisted of large and polyhedral cells with amphophilic cytoplasm which were arranged in cords separated by connective tissue. The cells exhibited an anaplastic appearance, with central nuclei, large amounts of granular chromatin and one or more evident nucleoli. Several mitotic figures, often incomplete and with consequent formation of multinucleated cells similar to giant cells, were observed. Immunohistochemical detection of cytokeratin and vimentin was performed for further examination. The ovarian tumor exhibited positive staining for cytokeratin and negative staining for vimentin. Discussion: Most ovarian tumors are asymptomatic and many times are considered incidental findings during spaying surgeries(...)