Long-Term Treatment Results for Ovarian Tumors with Malignant Effusion in Seven Dogs

Computed tomographic findings in dogs with ovarian tumors: A tortuous ovarian artery consistently identifies ovarian origin in complex abdominal masses

The aim of this retrospective multicentric case series is to describe the CT findings of ovarian neoplasia in dogs. Twenty dogs with pre- and postcontrast CT exams and cytological/histological diagnosis of ovarian neoplasia were included. Five dogs presented with bilateral tumors, for a total of 25 neoplasms: 15 carcinomas (4 bilateral), 4 granulosa cell tumors, 2 poorly differentiated malignant neoplasia (bilateral), 2 luteomas, 1 teratoma, 1 dysgerminoma. In two dogs, the tumor developed from an ovarian remnant. Ovarian tumors showed variable size, lobulated shape, and precontrast heterogenous appearance. Mineral foci and/or fat components were rare, observed in teratoma, granulosa cell tumors (2), and ovarian carcinoma. Tumor type was not found to be associated with any CT features. Larger masses were more likely located in the central abdomen ventral to the ipsilateral kidney, demonstrated signs of tumor rupture, and were associated with abdominal or sternal lymphadenopathy and peritoneal effusion. A tortuous ovarian artery was constantly detectable, associated with an enlarged gonadal vein (12 cases). Related cavitary changes were peritoneal effusion (14 dogs) and sternal lymphadenopathy (7 dogs). Presumed or confirmed metastasis was reported in 9 of 20 cases, with CT evidence of transcoelomic (serosal thickening, peritoneal nodules, omental cake, implant lesions to the liver, spleen, and diaphragm), lymphatic and hematogenous spread (lungs, liver, bone, muscles, and spleen). In conclusion, the present study reports the CT features of different canine ovarian neoplasia. A tortuous ovarian artery may be useful to consistently recognize the ovarian origin of a large abdominal mass.

Histopathology and indicators of borderline ovarian tumours with microinvasion in bitches

The authors present two cases of borderline ovarian tumours with microinvasion in bitches with variable clinical significance. The first case documents a four-year-old female Weimaraner diagnosed with a tumour on the right ovary during a veterinary check-up, using ultrasound (USG) examination, which was then surgically removed. Histological examination revealed a clear cell borderline tumour of the ovary with microinvasion. The second case is represented by a necropsy sample from a 52-month-old female German Shepherd who died a day before the planned hysterectomy due to undertreated pyometra. During necropsy, a developed bilateral ovarian tumour was found. An additional histological examination revealed a serous borderline tumour with microinvasion of both ovaries. This paper discusses the histopathological and clinical aspects involved in the prognosis of borderline ovarian tumours in bitches. This concerns the possibility of a change for a more aggressive behaviour of these tumours and their immunohistochemical profile, then the risk of implant metastases and, finally, the time point of diagnosis, intervention, and therapy. Even histologically verified well-differentiated forms of borderline ovarian tumours with microinvasion in bitches can show the variable clinical significance and, therefore, in similar cases, only a good or only a bad prognosis of the disease should not be expected.

Comparison of anti-Müllerian hormone and inhibin immunolabeling in canine and equine granulosa cell tumors

Granulosa cell tumors (GCTs) are common ovarian neoplasms in the mare and bitch that can be challenging to diagnose on histopathology. Inhibin has long been the standard immunohistochemical (IHC) marker for GCTs; however, anti-Müllerian hormone (AMH) has not been evaluated widely as an IHC marker in the bitch and mare. We compared the efficacy of AMH and inhibin as IHC markers in canine and equine GCTs. We selected retrospectively 18 equine and 15 canine cases. All equine tumors were dominated by a cystic pattern; canine tumors often had solid patterns. Both inhibin and AMH had similar punctate cytoplasmic patterns of immunolabeling, although labeling intensity was variable; distribution and intensity of labeling were unrelated to the histomorphologic pattern. Labeling for AMH occurred in 12 of 15 canine and 18 of 18 equine cases. Labeling for inhibin occurred in 15 of 15 canine and 18 of 18 equine cases. AMH in equine GCTs often had stronger immunolabeling than inhibin, and granulosa cells were labeled more extensively. Inhibin and AMH performed comparably in bitches, but AMH had more diffuse immunolabeling than inhibin in mares.

Immunohistochemical features of canine ovarian papillary adenocarcinoma and utility of cell block technique for detecting neoplastic cells in body cavity effusions

Dogs with ovarian papillary adenocarcinoma occasionally present with ascites and/or pleural effusion. These aspirated fluids often contain a large number of cells, and distinction between neoplastic cells and activated mesothelial cells can be difficult. In this study, 7 cases of canine ovarian papillary adenocarcinoma, including 3 with ascites and pleural effusion, were immunohistochemically examined. Ovarian tumor cells were positive for cytokeratin CAM5.2 (CAM5.2), Wilms’ tumor 1 (WT-1) and progesterone receptor (PR) in all 7 cases. A metastatic lesion of the mediastinum in one case was also positive for CAM5.2, WT-1 and PR. Immunohistochemistry on cell blocks obtained from ascites and/or pleural effusion of 2 cases revealed the presence of PR-positive epithelial cells. Whereas, activated mesothelial cells in ascites or pleural effusion collected from dogs without neoplastic lesions were negative for PR. In addition, surface epithelium and subsurface epithelial structures (SES) of normal canine ovaries, that are considered to be the cell of origin for ovarian papillary adenocarcinoma, were also positive for CAM5.2, WT-1 and PR. These results indicate that, together with CAM5.2, WT-1 and PR is a useful diagnostic marker for canine ovarian papillary adenocarcinoma. Expression of PR may be associated with progesterone-dependent nature of canine ovarian papillary adenocarcinoma.