concurrent tumors are a well - known entity , at times posing diagnostic and therapeutic difficulties . they can be synchronous , independently derived , nonmetastatic tumors , or metastatic tumors . distinguishing between them involves clinicopathologic interpretation based on multiple criteria including histologic type and grade . in general , if tumors at different sites have different histologic features , they are generally regarded as independently derived primary tumors , which generally have a better prognosis than the primary tumor with metastasis . very few case reports of synchronous bilateral primary ovarian tumors of different histologic types have been mentioned in the literature . here , we report a rare case of right ovarian clear cell carcinoma ( ccc ) with an incidental finding of left ovarian endometrioid carcinoma ( ec ) in a 65-year postmenopausal female . a 65-year - old postmenopausal multiparous , female presented to gynecologic outpatient department with history of pain in the right iliac fossa since 15 days . on abdominal examination , firm and tender lump was felt in the right iliac fossa . serum ca-125 was raised to 414 u / ml ( normal : 0 - 35 u / ml ) . computed tomography showed 9.5 cm  6.9 cm  6.8 cm sized well - defined , heterogeneous , partly solid and partly cystic lesion in pelvis superior to the urinary bladder . both ovaries were not seen separate from the lesion [ figure 1a ] . a radiological diagnosis of ovarian neoplasm was offered . intra - operatively , there was a presence of right adnexal tumor adhered to appendix and omentum . ( a ) computed tomography showing 9.5 cm  6.9 cm  6.8 cm sized well defined , heterogeneous , partly solid and partly cystic lesion in pelvis superior to urinary bladder . ( b ) the cut surface of the left ovary measuring 3.2 cm  1.5 cm  1 cm showing whitish and yellowish areas , the cut surface of the right ovarian mass measuring 10.5 cm  7.5 cm  4.5 cm showing predominantly solid with few cystic brownish areas . cysts varied in size from 0.5 to 2 cm the right adnexal mass measured 10.5 cm  7.5 cm  4.5 cm . uterus cervix with left sided adnexa measured 10 cm  8 cm  4.5 cm . external surface showed two subserosal nodules measuring 2.5 cm  2 cm  1.2 cm and 1.3 cm  1.5 cm  1 cm near the left cornu , cut surface of which showed whitish , whorled and firm areas . cut surface of the uterus showed distorted endometrial cavity with whitish , firm and whorled intramural nodule measuring 4.8 cm  4.3 cm  3 cm . the left ovary measured 3.2 cm  1.5 cm  1 cm , the cut surface of which showed whitish and yellowish areas [ figure 1b ] . ccc areas showed tumor cells arranged in solid sheets , tubulopapillary and focal cribriform pattern separated by hyalinized homogenous fibrovascular septae arising in an endometriotic cyst . sections from the left ovary showed infiltration by tumor cells at one pole with one focus of endometriosis . histopathological diagnosis of simultaneous presence of ccc in the right ovary [ figure 2a ] with the presence of ec in the left ovary [ figure 2c ] was made . ( a ) photomicrograph of ccc showing tumor cells arranged in solid sheets at places separated by hyalinized homogenous fibrovascular septae ; ( b ) the tumor cells of the right ovarian ccc showing absence of wt1 immunoreactivity ; ( c ) photomicrograph of ec showing glandular structures lined by malignant tumor cells . surrounding stroma is desmoplastic and shows dense chronic lymphocytic infiltrate ; ( d ) the tumor cells of the left ovary showing strong ema membrane immunoreactivity immunohistochemistry ( ihc ) was performed with the following panel of antibodies viz . wilm 's tumor gene ( wt1 ) ( clone 6f - h2 , dako ) , epithelial membrane antigen ( ema ) ( clone e29 , dako ) , estrogen receptor ( er ) ( clone 6f11 , novacastra ) , progesterone receptor ( pr ) ( clone pgr312 , novacastra ) and p53 ( clonedo-7 , dako ) on the tumors . the right ovarian tumor showed positivity for p53 , nuclear immunoreactivity for er and no immunoreactivity for wt1 , [ figure 2b ] and pr . the left ovarian tumor showed nuclear immunoreactivity for er and pr , p53 positivity , strong membrane immunoreactivity for ema [ figure 2d ] and no immunoreactivity for wt1 . based on ihc studies , diagnosis of ccc of the right ovary and ec of the left ovary was confirmed . external surface was nodular . cut surface showed predominantly solid with few cystic brownish areas . uterus cervix with left sided adnexa measured 10 cm  8 cm  4.5 cm . external surface showed two subserosal nodules measuring 2.5 cm  2 cm  1.2 cm and 1.3 cm  1.5 cm  1 cm near the left cornu , cut surface of which showed whitish , whorled and firm areas . cut surface of the uterus showed distorted endometrial cavity with whitish , firm and whorled intramural nodule measuring 4.8 cm  4.3 cm  3 cm . the left ovary measured 3.2 cm  1.5 cm  1 cm , the cut surface of which showed whitish and yellowish areas [ figure 1b ] . ccc areas showed tumor cells arranged in solid sheets , tubulopapillary and focal cribriform pattern separated by hyalinized homogenous fibrovascular septae arising in an endometriotic cyst . sections from the left ovary showed infiltration by tumor cells at one pole with one focus of endometriosis . histopathological diagnosis of simultaneous presence of ccc in the right ovary [ figure 2a ] with the presence of ec in the left ovary [ figure 2c ] was made . ( a ) photomicrograph of ccc showing tumor cells arranged in solid sheets at places separated by hyalinized homogenous fibrovascular septae ; ( b ) the tumor cells of the right ovarian ccc showing absence of wt1 immunoreactivity ; ( c ) photomicrograph of ec showing glandular structures lined by malignant tumor cells . surrounding stroma is desmoplastic and shows dense chronic lymphocytic infiltrate ; ( d ) the tumor cells of the left ovary showing strong ema membrane immunoreactivity immunohistochemistry ( ihc ) was performed with the following panel of antibodies viz . wilm 's tumor gene ( wt1 ) ( clone 6f - h2 , dako ) , epithelial membrane antigen ( ema ) ( clone e29 , dako ) , estrogen receptor ( er ) ( clone 6f11 , novacastra ) , progesterone receptor ( pr ) ( clone pgr312 , novacastra ) and p53 ( clonedo-7 , dako ) on the tumors . the right ovarian tumor showed positivity for p53 , nuclear immunoreactivity for er and no immunoreactivity for wt1 , [ figure 2b ] and pr . the left ovarian tumor showed nuclear immunoreactivity for er and pr , p53 positivity , strong membrane immunoreactivity for ema [ figure 2d ] and no immunoreactivity for wt1 . based on ihc studies , diagnosis of ccc of the right ovary and ec of the left ovary was confirmed . a synchronous malignant tumor is defined as the occurrence of two tumor types within a 6 months period in the same patient . the occurrence of primary synchronous malignancies of the genital tract is rare , the incidence of which varies between 0.7% and 1.5% . independent primary tumors of the endometrium and ovary are the most commonly encountered synchronous tumors of the female genital tract . very few case reports of bilateral synchronous primary ovarian malignant tumors have been mentioned in the literature . first case was reported in a 58 year postmenopausal lady with left ovarian serous papillary carcinoma and right ovarian malignant mixed mllerian tumor . second case was reported in a 38-year - female who had right ovarian serous papillary carcinoma and left ovarian ccc . clear cell carcinoma of the ovary , now recognized as a distinct entity , is the third most common ovarian carcinoma . it usually presents in international federation of gynecology and obstetrics ( figo ) stage i and ii . these unilateral tumors constitute 20 - 50% of ovarian carcinomas . endometrioid carcinoma , the second most common ovarian carcinoma , occurs in approximately 10% of all ovarian carcinomas . like ccc of the ovary , it also presents in figo stage i and ii . mutations in ctnnb-1 ( a - catenin ) , pi3ca ( encoding phosphatidylinositol 3-kinase ) , and pten have been reported to have high levels of microsatellite instability in ec . it is recognized that these tumors develop from endometriosis that is believed to develop as a result of retrograde menstruation . the oxidative stress conditions found within endometriotic lesions are likely to contribute to the transformation process . the dichotomy in the histogenesis of endometriosis associated ovarian cancer that is clear cell versus endometrioid type adenocarcinoma is further discussed in the literature . studies with the hepatocyte nuclear factor 1- ( hnf-1  ) by immunohistochemistry have addressed these issues . ec and ccc arise from the hnf-1 -negative and hnf-1 -positive epithelial cells of endometriosis , respectively indicating different cells of origin . at times , it can be very difficult to differentiate ccc and moderately differentiated ec of the ovary from ovarian serous cyst adenocarcinoma on histopathology alone . however , features such as rounded papillary cores with stromal hyalinization , surrounded by one or two layers of hobnail cells with uniform , but highly atypical nuclei with prominent nucleoli favor ccc . clinically , disseminated bilateral ovarian ccc at presentation is much less commonly encountered when compared with ovarian serous neoplasms . an endometriosis associated tumor composed of moderately atypical clear cells lining simple , back - to - back tubules helps recognizing ovarian ec . ovarian ccc is typically hnf-1  positive , er positive and wt1 , p16 , and p53 negative . ovarian ec retain er , pr positivity and are wt1 , p16 , p53 , and hnf-1  negative . ovarian serous neoplasms show diffuse wt1 , p53 , p16 , and er positivity and are negative for hnf-1 . it is known that agct with pseudo papillae can mimic ccc as happened while reporting on frozen section in this case the ca 125 levels help in approach to the diagnosis , therapeutics and followup of ovarian cancer . ovarian ccc though present at early stages have the propensity for recurrence even after primary chemotherapy . higher stages of ccc and higher grades of ec are seen to be associated with significantly decreased survival . findings in this case , thus highlight the role of ihc in histomorphological distinction of rare subtypes of ovarian carcinomas occurring bilaterally .
bilateral primary synchronous ovarian neoplasms are rarely encountered in clinical practice . both ovaries harboring neoplasms 
 is predominantly appreciated as , metastasis from a distant primary or secondary from an advanced primary ovarian neoplasm . 
 however in both the above instances , the histomorphological evaluation is of paramount importance . 
 we encountered an incidental left ovarian , international federation of gynecology and obstetrics grade 2 , endometrioid carcinoma in a patient presenting with a right ovarian mass immunohistopathologically proven to be clear cell carcinoma . 
 the documentation of such rare occurrence is of utmost importance for better understanding of histogenesis of ovarian cancers , which may impact management strategies .