Histopathological pattern of ovarian lesions: A Hospital based study in Batticaloa, Sri Lanka

Ovarian tumours are one of the most common neoplasms encountered in females. A five and a half year retrospective study was carried out in a tertiary care hospital to find out the frequency, age distribution and histopathological spectrum of ovarian lesions. There were 537 ovarian specimens sent for histopathological evaluation either as a solitary specimens or as part of total abdominal hysterectomy (TAH) from January 2012 to June 2017. Benign neoplastic lesions constituted most lesions diagnosed (49%). Among neoplastic ovarian lesions 80.1% cases were benign, 3.7% cases were borderline and 16.2% cases were malignant. Among benign ovarian neoplasms, 43.3% were serous cystadenomas; 30.0% were benign cystic teratomas and 22.4% were mucinous cystadenomas. Majority of malignant neoplasms were serous cystadenocarcinomas(58.5%) followed by mucinous cystadenocarcinoma, clear cell carcinoma, dysgerminoma and germ cell tumour.


Introduction
Ovaries are complex intra-pelvic organs of the female reproductive system and are a common site for both benign and malignant neoplasms in all age groups right from the intrauterine period to post-menopausal age group [1]. The complex anatomy of ovary and its peculiar physiology with constant cyclical changes from puberty to menopause is composed of a number of cell types each of which can give rise to tumours [4]. Almost 80% of the ovarian neoplasms are benign and it is also a common site for primary malignancy, although metastasis to ovaries can also occur [2]. Ovarian tumours are one of the major health problems confronting the General practitioners and Gynaecologists in particular. Ovarian carcinoma represents the sixth most common female cancer, the second most common cancer of the female reproductive system, and the fifth leading cause of death due to cancers in women [3].
Ovarian cyst can be physiological or pathological. Physiological cysts are mainly follicular cysts and luteal cysts which are benign in nature. Pathological cysts are mainly ovarian tumours which can be benign, borderline or malignant. Benign ovarian tumours are more common in young females and malignant tumours are more common in elderly females [5]. When an ovarian cyst is found, it is essential to recognize benign from malignant tumours.
The World Health Organization Histological Classification of ovarian tumours separates ovarian neoplasms according to the most probable tissue of origin: surface epithelial (65%), germ cell (15%), sex cord-stromal (10%), metastases (5%) and miscellaneous. Surface epithelial neoplasms are further classified by cell type (serous, mucinous, endometrioid) and atypia (benign, borderline or malignant; malignant may be invasive or non-invasive) (6) The ovary is anatomically situated within the pelvis which is not easily accessible. Further the symptoms of ovarian tumours are nonspecific. Therefore, identification of a high-risk population for ovarian malignancy and ideal screening methods are not available. Ovarian neoplasms present in various clinical forms and surprisingly many as vague, non-gynaecological complaints. Many ovarian neoplasms are asymptomatic in the early stages and some are unfortunately diagnosed in the advanced state due to the same reason. The high mortality rate of ovarian cancer is due to its late detection, thus earning itself the term "Silent Killer" [7].

Materials and methods
The study was undertaken as a retrospective study using existing patient data retrieved from the records of the Department of Pathology, Teaching Hospital, Batticaloa. The study was carried out to find out the different histological types of ovarian neoplasms and analyse their frequency and demographic details.
A total of 537 ovarian specimens were sent for histopathological evaluation from January 2012 to June 2017, either as solitary specimens or as part of total abdominal hysterectomy (TAH) specimens. The details of the histopathological diagnoses of the ovarian masses as well as the age distribution of the patients, were analysed using SPSS 21.

Results
Of the total 537 ovarian lesions 209 were nonneoplastic and 328 were neoplastic lesions (328). The distribution of the cases amongst these broad categories is given in Table 1. The distribution of non-neoplastic lesions is given in

Discussion
Ovarian neoplasms have become increasingly important not only because of its large variety of histo-morphological patterns but also because they have increased mortality rate in female genital cancers. The incidence, clinical appearance and the behaviour of the different types of ovarian tumours is extremely variable. This study shows that most (49%) of the ovarian lesions are benign. In a study by Swagata Dowerah et al, 84% of the tumors were benign [11]. This finding is similar to that of Vaidya et al [12] who reported 82% benign growths in their study. Several other studies have also found a higher percentage of benign tumours as compared to malignant [10,12,13,14].
In our study incidence of non-neoplastic lesions was 38.9 %( 209 out of 537). The finding was more or less similar to other studies where Kreuzer GF et al [15] reported 40.39% nonneoplastic lesions( 82 out of 203 ovarian lesions) and Martinez-Onsurbe P et al [16] reported 55 out of 132 (41.67%) non-neoplastic lesions.
Endometriosis is a common condition found in women of reproductive age. The most common location of endometriosis is the ovary and posterior cul-de-sac [17]. In our study 127 cases of endometriomas out of 537 cases (23.6%) were reported. Al Fozen H and Tulandi T [17] in a study conducted over a 6-year period reported 340 lesions out of which 155 (45.59%) showed ovarian endometriosis.
This study shows that majority of the ovarian cancers were found in women more than 40 years of age. This is comparable to the study by R Jha et al [13] in which malignant ovarian tumours was more common above 40 years. In this study, benign serous cystadenomas were found to be more common than mucinous cystadenomas. Similar results were reported by Sumaira Yasmin, et al [18], Swagata Dowerah et al [19] and Zubair M et al [20]. However, a study by Ahmed et al found that the most common benign tumour was benign cystic teratoma (35.17%) [21]. Similar finding was also reported by Vaidya et al [12].

Conclusion
This study shows that most of the ovarian lesions are benign than malignant in all age groups. Surface epithelial tumours are the most common class of tumours. Considering individual tumours, the most common benign tumour in this study is serous cystadenoma whereas serous cystadenocarcinoma was the most common ovarian malignancy. Malignant ovarian tumours were more common above 40 years.

Conflicts of interest None
Acknowledgement I wish to express my sincere gratitude to Dr. Ibralebbe, Director, Teaching Hospital, Batticaloa for providing me the opportunity to do this research in Teaching Hospital, Batticaloa. I sincerely thank my research assistant Dr. Hemika Yoganathan for tireless work. I also wish to express my gratitude to the officials and other staff members of Teaching Hospital, Batticaloa who rendered their help during this research period.