Ovarian Teratoma in a Mare

During a routine trip to a horse slaughterhouse, we found bilateral ovarian teratoma. Macroscopic findings were confirmed by the presence of hair, bones, and cartilage. Under microscopy, these tumors had mature foreign tissues as stratified squamous and respiratory epithelia, sebaceous and sweat glands, as well as follicular endocrine cells, inflammatory cells, hepatocytes, and hyaline cartilage.     

Immunohistochemistry Diagnosis of an Ovarian Dysgerminoma in One Bitch

An ovarian enlargement (diameter, 8 cm) was identified and surgically excised from a 5-year-old female dog. Microscopic examination of the multinodular neoplasm revealed sheets of polygonal neoplastic cells with large nuclei, frequent mitosis, necrosis and haemorrhage. Immunohistochemically, the neoplastic cells were positive for vimentin and alkaline phosphatase but were negative for CD3, CD79a, cytokeratin, alpha-fetoprotein, inhibin-α and S-100. The histopathological diagnosis of the mass was unilateral ovarian dysgerminoma.     

Clinicopathological Features of an Equine Ovarian Teratoma

The present study describes the clinicopathological features of a mature cystic ovarian teratoma occurred in a 4 year old, cyclic, nulliparous Andalusian mare. The mass was discovered in the left ovary during a breeding soundness examination, and was hard in consistency and variously echogenic. Laparoscopy was performed to confirm the neoplastic change, followed by a unilateral laparotomic ovariectomy in the standing animal. On the cut surface the teratomatous ovary showed a large cyst filled with hair and sebaceous material and three small cysts containing mucous fluid, surrounded by solid areas where bone and cartilage could be recognized. Exceptionally, functional remnants of the ovary, including small follicles and a diestral corpus luteum were found near the tubal extremity. Histology revealed mature tissues foreign to the ovary including stratified squamous and respiratory epithelia, mucous, sebaceous and sweat glands, muscle fibres, fat and nervous tissue. The appearance of tracheal and lung architecture was occasionally observed.     

Pseudo-placentational Endometrial Cysts in a Bitch

Cystic alterations of the canine endometrium compromise reproduction and fertility of the bitch and may lead to life-threatening diseases, such as pyometra. Even without clinical evidence, reduction of the uterine lumen by cysts implicates disturbances during migration, nidation and development of the embryo. Several studies point to the high variability of morphology of uterine endometrial cysts but they lack detailed analyses of alterations. In the present study, immunohistochemistry was used to investigate the expression of steroid hormone receptors (oestrogen, progesterone), proliferation activity, inflammation and infection in the cystic affected tissue regions in contrast to the normal endometrium. Oestrogen receptor expression showed a high density of receptors throughout the surface epithelial cells, crypt epithelial cells, glandular epithelial cells and stromal cells of the normal endometrium as well as the cystic affected regions. Proliferation in the cysts was verified in the middle and basal cells of the crypts. Neither in the endometrium nor in the cysts inflammatory processes or evidence of infection could be detected. Furthermore, lectin histochemistry and electron microscopic methods showed that lectin binding patterns and cell morphology of internal epithelial lining and surface epithelium of the cysts can be used to characterize and distinguish different types of cystic alterations. Analogies between epithelial cells of the glandular chambers of the canine placenta and the cystic cellular morphology, steroid hormone receptor distribution as well as lectin binding patterns of the endometrial cysts, as observed in this study, suggest to introduce the term 'pseudo-placentational endometrial cysts'.     

Osteolytic Osteosarcoma in a German Shepherd Bitch

Necropsy of a six year old female German Shepherd revealed the presence of a large oval mass in the thoracic cavity originating from the thickened proximal portion of the right fourth rib. Osteolytic osteosarcoma was diagnosed on the basis of gross appearance, presence of many pleomorphic spindle cells, containing pink stained intracytoplasmic granules in cytological preparations of impression smears of the tumor and histopathology. The tumor was considered highly malignant and was characterized by an abundant osteoblastic and connective tissue stroma with extreme cellular pleomorphism including giant cells, atypical mitoses and occasional trabeculae of tumor bone and osteoid. Metastases were found in the lung and spleen. Electron microscopy was carried out to support the diagnosis.     

Uterine Rupture in the Bitch

Abstract— An unusual case of rupture of the uterus in a parturient bitch with retention of the foeti in the abdominal cavity for one month after termination of the normal period of pregnancy.     

Pyometra in an Inguinal Hernia in a Bitch

Pyometra in an inguinal hernia was diagnosed in a 10‐year‐old intact cross‐bred bitch which had had dysorexia, depression and inguinal distension. The hernia contained caudal portions of the two uterine horns, uterine cervix and cranial part of the vagina. As the organs were enlarged and full of pus, manual attempt to push back the uterine horns and the vagina in the abdominal cavity through the inguinal canal was unsuccessful. Herniated uterine horns were ligated and cut in their median portion, so it became possible to remove the cervix and the caudal portion of the horns through the hernial orifice, and the ovaries and the cranial part of the horns through a peritoneal midline incision. This bitch was not intended for breeding purposes and, given the presence of a huge pyometra associated with an inguinal hernia, an ovario‐hysterectomy was recommended. Uterine herniation should be considered as a differential diagnosis of a caudal lateral inguinal mass. When pushing the uterus back in the abdominal cavity is impossible, a surgical procedure should be performed to detect ischemia–reperfusion injury and/or a septic risk.     

Bilateral Malignant Ovarian Teratoma With Peritoneal Metastasis in a Captive African Pygmy Hedgehog (Atelerix albiventris)

A 675-g, 1.4-year-old, female African pygmy hedgehog (Atelerix albiventris) was evaluated for progressive abdominal distension of 2 months duration. A large mass within the abdominal cavity was detected by radiography, ultrasonography, and computed tomography. The irregular, multilobulated mass, containing calcified, necrotic, and fatty areas was consistent with fused bilateral ovaries. Cytology of the mass suggested an ovarian adenoma or adenocarcinoma. The hedgehog died approximately 3 months after the initial presentation. Postmortem computed tomography and necropsy examination revealed a large bilaterally fused ovarian mass with peritoneal metastases. Histologically, the masses were composed of a variety of tissues from all 3 germ layers, including immature (embryonic) cells and neoplastic cells in the lymphatic system, which was consistent with malignant ovarian teratomas. This is the first report to describe malignant ovarian teratomas in a hedgehog.     

Regulation of Corpus Luteum-function in the Bitch

Functional lifespan of the corpus luteum (CL) in non-pregnant dogs exceeds that of pregnant animals and may last for more than 80 days. Prolactin and LH act luteotropic, however, luteolytic mechanisms are poorly understood. Other than in life stock there is no uterine luteolysine and it was postulated that local paracrine/autocrine mechanisms might play a major role. In following this hypothesis the present investigations have clearly demonstrated that up-regulation of prostaglandin synthesis in the CL as indicated by the expression of cyclo-oxygenase II occurs with its formation and not regression, pointing towards a luteotropic rather than luteolytic action. Throughout dioestrus luteal and other cells of the CL express the oestrogen (ERalpha) and progesterone receptor (PR). While ERalpha expression was not cycle-related, PR concentrations were high in the early and late-luteal phase and a regulatory role of both steroids on CL-function is assumed. As in other species also in the dog the immune system seems to participate in the mechanisms regulating CL-function as an increased presence of lymphocytes within the CL could be detected at the beginning [CD4- CD8-, major histocompatibility complex (MHC)II-antigen expressing cells] and during the latter half of dioestrus (CD8- and MHCII-antigen expressing cells). Thus, leucocyte-derived cytokines may be important and the expression of the mRNA for interleukin (IL)8, IL10, IL12, tumour necrosis factor (TNF)alpha and transforming growth factor (TGF) beta1 was observed throughout dioestrus. Electron microscopy confirmed the slow process of luteolysis; first distinct signs of degeneration were seen on day 60, accompanied by some apoptotic events. From these data it is concluded that luteal regression as monitored by the gradual decrease of systemic progesterone concentrations in the dog is not an actively regulated but rather a permissive process. Immune-mediated events may play a key role. Changes in the vascular supply, as indicated by the expression of endoglin, seem to be of lower importance.