Epidermoid Polycystic Ovaries and Uterine Hypoplasia in a Cow
Authors: Souza Natália Freitas , Assunção Pereira Washington Luiz , Dos Santos Andrade Sara Letícia , Oliveira Mour Marcio Alan , Da Costa Mileo Victor , Moreira Lima Moises , Tavares Rolim Filho Sebastião , Cardoso Jaques Adriana Maciel de Castro 
Published: March 2020

Background: Ovarian cysts originate from mature follicles that do not ovulate within the predicted time according to the oestrous cycle. Dermoid cysts are structures lined by keratinized stratified squamous epithelium, without adjacent epidermal structures, filled by keratinic debris and amorphous proteinaceus material. They are small, located below the cortex, near the hilus. There is controversy regarding the teratogenicity of the dermoid cyst. Some authors use the nomenclature of benign cystic ovarian teratoma, others, reports that although the fibrous wall and histological features are similar to teratomas, it is not associated with this germ cell-derived neoplasia.Case: Ovaries and uterus were received from a female, adult bovine, Nelore, from a slaughterhouse. The left ovary measured 6.5x5.0x3.9 cm and weighed 80 g; the right ovary measured 5.7x3.7x3.0 cm and weighed 60 g. Grossly, the ovaries were similar, presenting floating consistency, multilobulated and pointed aspect, and at the cut surface, there was extravasation of mucopurulent content of whitish colour. Regarding to the uterus, macroscopically, the uterine horns were infantile and decrease in the diameter. Fragments of the tissues were collected and fixed in 10% buffered formalin for histopathological examination and the staining of the slides was done with hematoxylin and eosin. Microscopically, in the ovaries, it was observed rare vestigial elements of ovary identifying an atresic follicle. Polycystic formation with cysts exhibiting partial or total coating of a keratinized squamous epithelium was also observed. In the lumen abundant keratinous material was present. The uterine microscopy revealed compact endometrium with areas variably infiltrated by lymphocytes, plasmocytes and occasional neutrophils. Areas devoid of endometrial glands were observed, in addition to other areas with reduced quantity and size. Also, the myoepithelial layer was thin and enlargement of the endometrial vascular space was noted.Discussion: Only one study was found reporting three cases of unilateral dermoid cyst in bovine ovary, also from slaughterhouse. Dermoid cysts appear most often in Zebu cattle. Clinically, these cysts do not necessarily result in infertility and do not interfere in the ovarian functions, due to this, the ovaries are not referred for histopathology examination, which difficult its classification. However, in this study the histological examination showed the absence of follicular development, which characterizes infertility, including endocrine dysfunction. Macroscopically ovarian dermoid cysts are similar to abscesses. It has a viscous or milky content inside and, at the cut surface, usually the content project to the surface. Histologically, there are dilated cysts containing material in the lumen at various stages of keratinization conferring a lamellar aspect and a keratinized stratified squamous epithelium. In this study, we observed pseudostratified epithelial lining containing cilia in addition to lumen keratin content, without follicles or adnexal structures, corroborating the findings in the literature. Also, it was observed uterine hypoplasia, which occurs due to failure of the development of the paramesonephric ducts during embryonic development. Ovarian dermoid cysts associated with uterine hypoplasia are infrequent in animals and, clinically, may not present changes in fertility and ovarian function.