Diagnosis and surgical management of ovarian tumours in the mare

Diagnose und chirurgische Behandlung von Ovartumoren des Pferdes

Bartmann C P, Schoon H-A, Hoppen H O

DOI: 10.21836/PEM20010202
Year: 2001
Volume: 17
Issue: 2
Pages: 111-119

During a four year period, 31 mares underwent an unilateral ovariectomy as a result of the diagnosis of ovarian neoplasia. The diagnosis was based on the results of behavioural control, clinical, ultrasonographical and endocrinological (circulating levels of T, E2, P4) examination added by collection and patho- and immunohistological examination of endometrium biopsy specimens. Typical findings in mares with postoperatively confirmed granulosa cell tumour included stallion like behaviour, unilateral enlargement of the affected ovary with atrophy of the inhibited contralateral ovary and abnormality in different variations in the ultrasonographical appearance of the neoplastic ovary. Prior to ovariectomy serum testosterone levels were remarkably elevated in 13 of the 31 mares. Surgical procedures included flank approach by modified grid technique or ventral midline approach with exteriorization and complete resection of the affected ovary under general anesthesia. Pathohistological examination of the 31 ovaries revealed 28 granulosa cell tumours, one thecoma, one cystadenoma and one malignan teratoma. With only one exception, even clinically and endocrinologically unclear remaining granulosa cell tumours were associated with an irregular endometrial differentiation (IED) possibly indicating a hormonal activity of the tumour cells. The teratoma and the cystadenoma did not affect the endometrial differentiation.Irregular endometrial differentiation may indicate hormonal disturbances due to ovarian neoplasia and serves as a distinct bio assay which is available prior to surgery. In addition to clinical, ultrasonographical and endocrinological findings, endometrial biopsy is a useful aid in the evaluation of abnormal ovaries.