DISCUSSION
SPEOC is found in approximately 10% of all females with ovarian cancer and in 5% of all females with endometrial cancer. As the entity is uncommon, it is often misdiagnosed as FIGO stage III of endometrial cancer or FIGO stage II of ovarian cancer.5The majority of women with SEOC are 41–54 years old, 40% of them are nulliparous, 2/3 of them are premenopausal, and 1/3 are obese.7 In the reported case, the patient is multiparous, premenopausal, and had a BMI of 25.4kg/m2. Moreover, SPEOC is observed among the younger age group as compared to endometrial or ovarian cancer alone.8
As with this case, abnormal uterine bleeding is the most common presentation of synchronous endometrial and ovarian cancer, though some patients may present with pelvic pain or a palpable pelvic mass.7 In ultrasonography, most of the ovarian masses in SPEOC appear as unilateral multilocular-solid or solid mass but such ovarian masses in cases of endometrial cancers with ovarian metastasis are often solid masses bilaterally.9Our patient also had a solid-cystic lesion in her left ovary only supporting this statement.
The Endometroid subtype of the primary tumors is the commonest histological finding which is found in 50–70% of cases and the primary independent tumors often grade 1 or 2.7 In the reported case, it was endometroid subtype with histological grade 2.Development of surface epithelium of the ovary from the embryological Mullerian duct and sharing of estrogen receptors in predisposed tissues are the likely reasons for their synchronous growth.10Because of this common histological finding in both the localization, differentiation of the primary origins from primary endometrial cancer with metastases to ovaries, or primary ovarian cancer with metastases to the endometrium is pivotal.11  In our case, histology revealed no evidence of metastasis as the  tumor from the section of endometrium was limited to the inner half of the myometrium and 5mm within the capsule of the ovary without lymphovascular invasion.
Although primary surgery has been recognized as the main treatment for SPEOC, whether adjuvant therapy should be administered remains controversial. Using FIGO guidelines, a patient with dual primaries limited to the ovary and the uterus represents two Stage I cancers. Systematic surgical staging is the mainstay of the management for such patients and often includes total abdominal hysterectomy with bilateral salpingo-oophorectomy, total omentectomy, appendectomy, pelvic and para-aortic lymphadenectomy, and complete resection of all diseases.10Considering the positive frozen section examination, our patient too underwent the aforementioned staging surgery.
These patients have a good prognosis and depending on the substage may not require radio or chemotherapy. However, no guidelines for adjuvant therapy in patients with synchronous cancers have been established yet and the treatment of respective cancer guides the adjuvant treatment. In ovarian cancer, all but stage IA/B are to receive chemotherapy and in endometrial cancer, it is indicated when the risk of distant metastasis is high.11Considering stage Ia of the ovarian tumor, adjuvant  chemotherapy was not given to our patient.
The prognosis of patients with synchronous endometrial and ovarian carcinoma is better than the patients with single-organ cancer with ovarian or endometrial spread with the median 5-year disease-free survival (DFS) rate reported to be 65% for synchronous endometrial and ovarian cancer but is less than 50% for stage IIIA endometrial cancer with ovarian spread.12,13A review of 43 cases of SPEOC showed that nine patients had recurrence (20.93%). The median time to recurrence was 10 months (range, 5–30). The five-year survival rate of the patients was 86.05%.8In addition, A study of double cancer in 1500 patients showed that the prognosis improved with younger age (less than 55 years), earlier stage, lower stage, the premenopausal state, and lymph node dissection.13Also, synchronous primary endometrial and ovarian cancer endometroid types have better overall survival than patients with non-endometrioid or mixed histologic types.14Considering all, the prognosis of our patient is good and our patient is now disease-free at nine months of surgery and is under regular follow-up.