The Evaluation of Clinicopathological and Immunohistochemical Findings of Cervical Clear Cell Carcinoma in a Bitch

Abstract

Background: Clear cell carcinoma (CCC) of the cervix is a rarely seen malignant tumor which is classified in adenocarcinomas of the endometrium. It is responsible for 2.15-3.0% of endometrial tumors. The diagnosis is difficult and is still controversial in uterine carcinomas. Macroscopically, masses were protruding to endometrial surface. However, the definitive diagnosis was carried by microscopical evaluation. The cells contain clear cytoplasm. The cells are seen in this pattern because there is either glycogenation or secretoric activity in the cells.
Case: In the present case, clinicopathologic and immunohistochemical findings of clear cell carcinoma of the cervix were defined in a 3 year-old spayed Golden retriever bitch. Previously spayed bitch, which had vaginal discharge for the last month-long, was submitted to the Department of Obstetrics and Gynecology, Ankara University, Faculty of Veterinary
Medicine. In the general clinical examination, vaginoscopy was performed and vaginal cytology was obtained from smear. The source of discharge was detected as cervix uteri. In vaginal cytologic examination, erythrocyte, neutrophile and superficial cells were observed. In abdominal ultrasonography, a hypoechoic mass was detected at cranial part of the urinary bladder. To evaluate the general health condition of the dog, total blood counting and serum biochemistry were analyzed in addition to assessing its hormone prophlye. Estrogen and progesterone levels were evaluated. Estradiol (E2) level was measured as 23 pg/mL and progesterone level was measured as 1.96 ng/mL from collected serum. The cervical mass in diameters of 3x4x2.5 cm was removed in operation. In macroscopical examination, it had spherical and regularly shape.
After the macroscopical examination, tissue samples were fixed in 10% buffered formalin. Then, the samples stained with Haematoxylin-Eosin (H&E), Masson’s trichrome and PAS stainings, respectively. At the macroscopic and histological examinations, the mass was diagnosed as clear cell carcinoma. Immunohistochemically, the tumor was stained with CK19 α-SMA, vimentin, desmin, TGF-β, VEGF, CEA, ER and PR markers. Other markers gave moderate to severe reactions in exception for no or weak ER and PR positivities. In direction of these results, clear cell carcinoma of cervix had been found remarkably due to first description in a spayed bitch on the basis of knowledge.
Discussion: Clear cell carcinoma (CCC) is one type of the endometrial carcinomas. It is frequently known to have aggressive behavior and unfavorable prognosis. In human counterparts, clear cell carcinoma is frequently reoccurred in caudoabdominal and pelvic region even after being removed. The occurrence of clear cell carcinoma has highly increased
with diethylstilbestrol usage during pregnancy. The situation on uterine carcinoma is nearly same in domestic animals. It is related to prolonged estrogenism. In this case, the bitch has been under prolong exposure to estrogenic effect. Indeed the estradiol level was high when compared to spayed female. Also, it is thought that the reason of high estradiol level
does not depend on the ovarian remnant. It is believed this situation may be relevant to exogen hormone usage. Vaginal smear confirmed erythrocyte (due to bleeding), predominantly superficial cells to it’s under estrogenic effect even despite being spayed.
Keywords: clear cell carcinoma, cervix, clinicopathology, marker, bitch.