Canine Ovarian Neoplasms: A Clinicopathologic Study of 71 Cases, Including Histology of 12 Granulosa Cell Tumors

Abstract

Abstract. In a retrospective study of 71 primary ovarian tumors in the dog, epithelial tumors (46%) were more common than sex cord stromal (34%) and germ cell tumors (20%). There were more adenocarcinomas (64%) than adenomas. Sex cord stromal tumors were equally divided into Sertoli-Leydig (1 2/24) and granulosa cell tumors (12/24). There were equal numbers (7/14) of dysgerminomas and teratomas among the germ cell tumors. Most teratomas (6/7) were malignant. Most granulosa cell tumors were solid; two were mostly cystic. Patterns included sheets of round and ovoid to spindle-shaped cells separated by thin, fibrovascular stroma; neoplastic cells formed rosettes or Call-Exner bodies. In some areas, neoplastic cells were in cords or columns and formed cyst-like structures. Four granulosa cell tumors were macrofollicular, having cysts lined with granulosa cells. Median ages of dogs with different ovarian neoplasms were similar; all were more than 10 years old, except the dogs with teratoma (mean age, 4 years). Most neoplasms were unilateral (84'?0), except the SertoliLeydig cell tumors, many of which were bilateral (36%). Size of ovarian neoplasms varied (2 cm3 to 15,000 cm3). Twenty-nine percent of neoplasms metastasized; adenocarcinomas (48%) and malignant teratomas (50%) had the highest rates, and distant metastasis was more common in malignant teratoma. Endometrial hyperplasia was in 67% of the dogs; it was most common in dogs with sex cord stromal tumors (95%). Uterine malignancy was not seen in dogs with granulosa cell tumors, although hyperplastic endometrium was in all dogs with this tumor. Cysts in the contralateral ovaries were most common in dogs with sex cord stromal tumors.Canine ovarian neoplasms can be broadly divided into three major categories: (1) germ cell, (2) epithelial, and (3) sex cord stromal. The rate of occurrence of these three histologic types varies in different studies. Epithelial neoplasms are most common in some studies,2J2 and sex cord stromal tumors are most common in o t h e r~.~J~ Adenocarcinomas were more common than their benign counterparts in two studies that used the same source m a t e~i a l .~, '~ Germ cell tumors were less prevalent than the other two types of tumor in all these studies, and dysgerminomas were more common than teratomas in most of them.2s5*7J2J3 In all of these ~t u d i e s~,~,~J~ except one,I2 no distinction was made be- Materials and MethodsA 10-year retrospective survey of the medical records at The Animal Medical Center yielded 7 1 dogs with adequate tissue specimens to confirm a diagnosis of primary ovarian neoplasm and to classify the tumors. Contralateral ovarian and uterine specimens, whenever available, were also examined. Age, breed, clinical, and gross pathologic descriptions were obtained from records. Tissues were fixed in 10% buffered formalin, processed routinely, sliced at 6 pm, and stained with hematoxylin and eosin (HE), mucicarmine, periodic acid-Schiff (PAS), and modified Grimelius stains. Histologic classification was based on the majo...

A Case Resport of an Uncommon Sex-Cord Stromal Tumor Consisted of Luteal and Sertoli Cells in a Spayed Bitch

“…In a later published retrospective study of 71 primary ovarian tumors in dogs, the incidence of epithelial tumors (46%) was slightly higher than that of sex cordstromal tumors (34%) or germ cell tumors (20%) [19]. Sex cord-stromal tumors were then equally divided into SertoliLeydig and granulosa cell tumors, and there was no indication of steroid cell tumors or luteomas.…”

“…72(2): 229-234, 2010 In the old literature, a variety of types of sex cord-stromal tumors have been reported in bitches, such as granulosa cell tumor, Sertoli cell tumor, luteoma, and nonspecific stromal tumor [2,6,16]. In a later published retrospective study of 71 primary ovarian tumors in dogs, the incidence of epithelial tumors (46%) was slightly higher than that of sex cordstromal tumors (34%) or germ cell tumors (20%) [19]. Sex cord-stromal tumors were then equally divided into SertoliLeydig and granulosa cell tumors, and there was no indication of steroid cell tumors or luteomas.…”

Ovarian Choriocarcinoma in a Rhesus Monkey Associated with Elevated Serum Chorionic Gonadotropin Levels

“…Surveys of ovarian tumors in dogs, cats, and rats have failed to reveal any cases. 3,4,11 Eight cases have been reported in B6C3F1 mice, seeming to indicate an increased susceptibility in that strain. 1,2 Beyond that, no case reports of ovarian choriocarcinoma in nonprimate species can be found.…”

A literature review on the welfare implications of gonadectomy of dogs

“…46,48 Age of occurrence, rate of metastasis, and frequency of concurrent uterine malignancy or endocrine disease are dependent on the type of neoplasia. [44][45][46][47]49 Ovariectomy or OHE would be preventive and is the mainstay of treatment, but gonadectomy would only be helpful for benign or localized ovarian tumors. 11,43 The prognosis is poor for patients with malignant neoplasia with evidence of metastatic disease, which can occur in up to 50% of cases.…”