Serous Component Research Articles

Minor serous or clear-cell components in early-stage endometrioid adenocarcinoma: is it ever insignificant?

Evaluation of: Quddus MR, Sung CJ, Zhang C, Lawrence WD. Minor serous and clear cell components adversely affect prognosis in ‘mixed-type’ endometrial carcinomas: a clinicopathologic study of 36 stage-I cases. Reprod. Sci. 17(7), 673–678 (2010).Endometrioid adenocarcinomas of the endometrium occasionally display a small proportion of serous or clear-cell adenocarcinoma, two of the high-grade histotypes. Since the adjuvant management for patients with low-grade, early-stage endometrioid adenocarcinoma is so different from the management of their counterparts with the serous or clear histotypes, this situation poses a significant conundrum. The article under evaluation compared the overall survival between patients with stage I endometrioid adenocarcinomas with a minor serous or clear-cell component, and an age- and stage-matched control group comprised of pure endometrioid, clear-cell and serous adenocarcinomas. Preliminary analyses suggest that these minor components, even in small proportions, may advers...

Minor Serous and Clear Cell Components Adversely Affect Prognosis in “Mixed-Type” Endometrial Carcinomas: A Clinicopathologic Study of 36 Stage-I Cases

Most endometrial carcinomas contain only 1 Müllerian cell type although the presence of 2 or more cell types within 1 tumor, for example a predominantly low-grade endometrioid carcinoma with a minor component (arbitrarily defined as 30% or less) of high-grade serous and/or clear cell carcinoma, is not uncommon. The current study attempts to evaluate whether the presence of minor serous or clear cell components exerts an adverse effect on the prognosis in stage-I endometrial carcinomas of ''mixed-type.'' The study cases include 22 cases of stage-I endometrioid carcinoma with a minor component of serous carcinoma and 14 cases of endometrioid carcinoma with a minor component of clear cell carcinoma. Minor components were arbitrarily defined as representing anywhere between 5% and 30% of the total tumor. The study cases were compared with 56 cases of histologically pure age-matched and stage-matched endometrioid carcinomas, 6 pure serous carcinomas, and 13 pure clear cell carcinomas. All study and control cases were fully staged. Treatment history and outcome status were obtained and follow-up ranged from 56 to 140 months. Our study suggests that the presence of minor components of serous and clear cell carcinoma, defined as between 5% and 30%, within a mixed-type endometrial carcinoma appears to adversely influence the long-term survival of stage-I tumors, although a larger study is needed to corroborate our findings.

IMP3 Distinguishes Uterine Serous Carcinoma From Endometrial Endometrioid Adenocarcinoma

Differentiating uterine serous carcinoma (USC) from endometrioid adenocarcinoma (EAC) could be problematic, especially in high-grade EACs and tumors exhibiting architectural variations. To address this issue, we evaluated 103 endometrial carcinoma cases using 4 immunomarkers, beta-catenin, IMP3, PTEN, and p53. Cases included 31 USCs, 57 EACs, and 15 mixed EAC-USCs. Of 31 USCs and 57 EACs, 8 and 9, respectively, were considered diagnostically difficult and challenging. beta-catenin was more frequently expressed in EAC (P = .001); p53, PTEN, and IMP3 were more frequently found in USC (P < .001 for each). IMP3 was the best independent predictive marker for USCs. The best marker combination for predicting USCs was PTEN+/IMP3+ (exact odds ratio, 163.87; 95% confidence interval, 19.62 to infinity; P < .001). IMP3 was consistently negative in all 9 challenging EAC cases and consistently positive in all 8 challenging USC cases. None of the markers or their combinations demonstrated any value in making the diagnosis of serous component in mixed EAC-USC tumors. IMP3 immunoexpression and the IMP3+/PTEN+ pattern are the best independent and combination markers, respectively, to predict USCs. We strongly recommend using them in difficult and challenging cases.

Mixed type endometrial carcinoma: Clinicopathologic comparison between two large academic institutions.

e15559 Background: The diagnosis of endometrioid carcinomas, mixed type, is based upon presence of a serous component varying from 10% to 25%. This range may introduce variation and subjectivity in...

Newly diagnosed and relapsed epithelial ovarian carcinoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

Newly diagnosed and relapsed epithelial ovarian carcinoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

Morphologic Changes in Ovarian Carcinoma After Neoadjuvant Chemotherapy: Report of a Case Showing Extensive Clear Cell Changes Mimicking Clear Cell Carcinoma

Neoadjuvant chemotherapy followed by interval debulking has become an alternative treatment option for patients with advanced-stage ovarian cancer. The effects of chemotherapy on the histologic features of the tumor have not been well described for ovarian carcinoma, especially related to changes that significantly alter the appearance of the tumor. In this study, we describe a case of ovarian serous carcinoma status-post neoadjuvant chemotherapy that showed exuberant clear cell/foamy change. This unusual morphology raised the possibility of a mixed epithelial carcinoma or a secondary malignancy. Immunohistochemical stains were performed to help distinguish whether the tumor was a serous carcinoma with chemotherapy-induced clear cell change or a distinct clear cell carcinoma of ovarian or extraovarian origin. The clear cell and conventional serous components showed diffuse positivity for CK7, CA125, and ER; however, only the clear cell component was positive for hepatocyte nuclear factor-1beta and only the conventional serous component was positive for WT1. Although there was a slight discrepancy in the staining patterns, given the lack of other typical histologic features of clear cell carcinoma, the unusual clear cell morphology was most likely the result of chemotherapy-induced changes.

Endometriale Karzinome und Vorstufen – Neue Aspekte

Endometrial carcinomas can be separated into two groups which are designated as type I and type II carcinomas today. Both groups of tumors are clearly different with regard to conventional light microscopy, immunohistochemistry, molecular pathology and clinical features. Only type I carcinomas are associated with hyperestrogenism. The group of type I carcinomas consists of endometrioid carcinoma and its variants, and mucinous carcinoma. The prototypes of type II carcinomas are serous and clear cell carcinoma. Not all carcinomas, however, can be assigned to one of the two groups, because there are hybrid tumors and mixed carcinomas, e.g. endometrioid carcinoma with a serous component. The precursor lesions of the endometrioid carcinoma and the serous carcinoma are well characterized morphologically and by molecular pathology. Atypical hyperplasia is the precursor lesion of endometrioid carcinoma, whereas endometrial intraepithelial carcinoma (EIC) is the precursor lesion of serous carcinoma. No precursor lesion has as yet been identified for clear cell carcinoma. Immunohistochemical markers for endometrial carcinoma are CK7 and vimentin, for serous carcinoma markers are p53 and p16. Correct typing is of essential prognostic necessity in endometrial carcinoma. Of utmost importance is the detection of a serous component, because serous carcinoma leads to early tumor spread with the necessity of radical surgery, chemotherapy and radiotherapy.

Seromucinous hamartomas: a clinicopathological study of a sinonasal glandular lesion lacking myoepithelial cells

To describe seven cases of sinonasal seromucinous hamartoma. The clinicopathological and immunohistochemical features of seven seromucinous hamartomas were analysed. There were four men and three women. Six lesions involved the posterior nasal septum and one the lateral wall. Size ranged from 6 to 40 mm. Four patients had no recurrences. One patient had local recurrences 24 and 60 months after diagnosis. The masses were covered by respiratory epithelium. Their stroma was oedematous to fibrous and contained invaginated respiratory epithelium forming glands and cysts, cysts with cuboidal to flat epithelium, and small serous glands, ducts and tubules with lobular and irregular haphazard patterns. One case had numerous glands surrounded by hyalinized basement membrane with features of respiratory epithelial adenomatoid hamartoma (REAH). One case had focal REAH-like changes. Both respiratory and serous components were positive for cytokeratin (CK) 7 and CK19. The serous component lacked myoepithelial cells when stained for CK14, p63, calponin and muscle-specific antigen in five cases. Seromucinous hamartomas show a broader histopathological appearance than previously reported. The serous proliferation in these lesions lacks myoepithelial cells. The presence of occasional REAH-like features and common location in the posterior nasal septum suggest a spectrum from pure seromucinous hamartoma to REAH.

Meningeal Carcinomatosis and Uterine Carcinoma: Three Different Clinical Settings and Review of the Literature

Leptomeningeal carcinomatosis is a rare metastatic event in gynecological neoplasias, and most cases occur in ovarian cancer. It is extremely infrequent in cervical cancer, and so far, there are not any reports of this complication in association with endometrial cancer. We report a case of leptomeningeal carcinomatosis secondary to endometrial carcinoma and 2 complex cervix cancer cases. A MEDLINE search was done to review all published cases of this complication in gynecological cancer to identify predictive factors for this diagnosis. Leptomeningeal carcinomatosis is usually diagnosed late in the course of the disease, and most reports concern ovarian cancer patients. The number of cases describing this neurologic complication in cervix cancer is increasing. Gadolinium-enhanced magnetic resonance imaging may be necessary for this diagnosis, because cerebrospinal fluid analysis results may be negative. Most cervix cases had squamous cell (8/14) or neuroendocrine histologic subtype (3/14), and when reported, differentiation was usually poor. The case we report of endometrial carcinoma, unique in the literature, is a serous adenocarcinoma. A high index of suspicion is necessary, and leptomeningeal carcinomatosis should be considered in patients with unexplained neurologic symptoms whose gynecologic tumors are poorly undifferentiated or have a serous component.

Combined Large Cell Neuroendocrine Carcinoma and Papillary Serous Carcinoma of the Endometrium With Pagetoid Spread

Neuroendocrine carcinomas of the endometrium are rare tumors that can be pure, combined with endometrioid adenocarcinoma, or a component of malignant mixed müllerian tumor. Recently, a case of combined small cell carcinoma and papillary serous carcinoma of the endometrium was described for the first time. We report the first case, to our knowledge, of combined large cell neuroendocrine carcinoma and papillary serous carcinoma of the endometrium, with an unusual pagetoid spread of the neuroendocrine component into normal endometrial and endocervical glands. The endometrial carcinoma had a small serous component, but most of the tumor was characterized by solid sheets of medium to large cells with abundant mitotic figures, numerous apoptotic bodies, and foci of necrosis. This component was diffusely positive for neuroendocrine markers. Following surgery, the patient was treated with radiation therapy and chemotherapy. She was without evidence of progression at 5 months of follow-up.

Combined Large Cell Neuroendocrine Carcinoma and Papillary Serous Carcinoma of the Endometrium With Pagetoid Spread

Neuroendocrine carcinomas of the endometrium are rare tumors that can be pure, combined with endometrioid adenocarcinoma, or a component of malignant mixed mullerian tumor. Recently, a case of combined small cell carcinoma and papillary serous carcinoma of the endometrium was described for the first time. We report the first case, to our knowledge, of combined large cell neuroendocrine carcinoma and papillary serous carcinoma of the endometrium, with an unusual pagetoid spread of the neuroendocrine component into normal endometrial and endocervical glands. The endometrial carcinoma had a small serous component, but most of the tumor was characterized by solid sheets of medium to large cells with abundant mitotic figures, numerous apoptotic bodies, and foci of necrosis. This component was diffusely positive for neuroendocrine markers. Following surgery, the patient was treated with radiation therapy and chemotherapy. She was without evidence of progression at 5 months of follow-up.

Mixed Ovarian Epithelial Carcinomas With Clear Cell and Serous Components are Variants of High-grade Serous Carcinoma

There are conflicting data about chemoresistance and prognosis in ovarian clear cell carcinoma (CCC). This could be due to significant interobserver variation in the diagnosis of CCC and other ovarian surface epithelial tumors containing clear cells. Thirty-two cases previously diagnosed as CCC, high-grade ovarian serous carcinoma (SC), and mixed surface epithelial carcinoma (SEC) with clear cell and serous components were reviewed by 4 gynecologic pathologists blinded to the original diagnoses. Interobserver reproducibility was evaluated. Each case was also assessed using immunohistochemical markers Wilm tumor 1, estrogen receptor, and p53. The interobserver reproducibility was greatest for pure CCC (kappa of 0.82), and lowest for the mixed SEC (kappa of 0.32). Moderate agreement was seen in the pure SC category (kappa of 0.59). All pure SC and most mixed SEC presented as stage III or IV diseases. Most pure CCC presented as stage I or II diseases. Immunoreactivities of the mixed SECs were similar to those of pure SC, but significantly different from those of pure CCC for Wilm tumor 1 (P=0.0011 for both components), estrogen receptor (P=0.0003 for clear cell component, P=0.0001 for serous component), and p53 (P=0.0062 for both components). The serous and clear cell components of mixed SEC showed higher mitotic rates than pure CCC (P=0.004 and P=0.023, respectively), but the mitotic rate of pure SC was similar to the mixed SEC. We conclude that (1) pure CCC is reproducibly diagnosed. (2) The diagnosis of mixed ovarian SEC with clear cell component is not reproducible. (3) Mixed SEC with clear cell and serous components show similar stage, mitotic activities, and immunoreactivities to those of pure SC, and likely represent SC with clear cell changes.

Mixed serous carcinoma of the endometrium with trophoblastic differentiation: analysis of the p53 tumor suppressor gene suggests stem cell origin

The pathogenesis of mixed endometrial adenocarcinoma with trophoblastic differentiation is quite unclear at times. The present study examines a serous carcinoma with choriocarcinomatous differentiation. p53 staining was seen in the serous component and the cytotrophoblastic cells of the choriocarcinomatous component, but not in the syncytiotrophoblastic cells. p53 mutational analysis showed a heterozygotic mutation at exon 8 for the choriocarcinomatous component and a homozygote deletion at exon 7 for the serous component. These alterations suggest that the multidirectional tumor differentiation might occur from a common stem cell in these malignancies.

The effect of epithelial and stromal tumor components on FIGO stages III and IV ovarian carcinosarcomas treated with primary surgery and chemotherapy

The aim of this study is to assess the effect of epithelial and stromal tumor components on survival outcomes in FIGO stage III or IV ovarian carcinosarcomas (OCS) treated with primary surgery and adjuvant chemotherapy at the Northern Gynaecological Oncology Centre (NGOC), Gateshead. Women were identified from the histopathology/NGOC databases. Age, FIGO stage, details of histology, treatment, and overall survival were recorded. Of 34 cases (1994-2006, all FIGO stages), 17 were treated with primary surgery followed by adjuvant chemotherapy for FIGO stage III or IV. The median age was 66 years (52-85 years). Cytoreduction was optimal (n= 9) or complete (n= 1) in 10/17 (59%) cases. Epithelial predominant (EP) or stromal predominant (SP) tumor (defined as >50% of either component in the primary tumor) was noted in 12 and 5 cases, respectively. Epithelial types included serous (n= 9), endometrioid (n= 5), and mixed types (n= 3). Twelve women have died of disease. The median overall survival was 11.0 months (3-74 months). On univariate analysis, survival was not affected by optimal/suboptimal debulking, platinum/doxorubicin-containing chemotherapy, or homologous/heterologous stromal components. Stromal components (>25%) adversely affected survival (P= 0.02), and there was a trend to worse survival with serous compared with nonserous epithelial components (P= 0.07). Cox regression (multivariate analysis) showed that SP tumors (P= 0.04), suboptimal debulking (P= 0.01), age (P= 0.01), and tumors with serous epithelial component (P= 0.05) were adverse independent prognostic factors. Type of chemotherapy and homologous/heterologous components (P= 0.24) did not affect overall survival. In conclusion, our study suggests that SP-OCS have a worse survival outcome than EP tumors. Tumors with serous epithelial components adversely affected the survival compared with nonserous components. Larger studies are required to confirm these effects and to identify the optimum chemotherapy regimen for OCS.

Aggressive mixed type endometrial carcinoma in a young woman with rapid progression and fatal outcome

Endometrial carcinoma in young ages is uncommon and tends to be a well differentiated endometrioid type and has an excellent prognosis. Nevertheless, in this report mixed type endometrial cancer including serous, clear cell and endometrioid components in a young patient with rapid progression and fatal outcome is presented. A 26-year-old virgin female was admitted with menometrohagia lasting for 9 months, leading to severe anemia. Transabdominal ultrasonography demonstrated 30 x 27 mm intramural mass consistent with leiomyoma in uterine corpus posterior. The patient did not permit any vaginal intervention including endometrial sampling, therefore laparotomy was decided. Mixed type endometrial carcinoma was diagnosed and she was treated with comprehensive surgery plus adjuvant chemotherapy. After 7 months of surgery she deceased. We suggest that persistent uterine bleeding associated with severe anemia should be evaluated for malignancy even in young women to avoid delay in diagnosis. Imaging studies especially magnetic resonance imaging may be helpful when endometrial sampling cannot be done.

The Development of High-grade Serous Carcinoma From Atypical Proliferative (Borderline) Serous Tumors and Low-grade Micropapillary Serous Carcinoma

Recently, we have proposed a model for the development of ovarian surface epithelial tumors. In this model, all histologic types of surface epithelial tumors are divided into 2 categories designated type I and type II which correspond to 2 pathways of tumorigenesis. Type I tumors include low-grade serous carcinoma, mucinous carcinoma, endometrioid carcinoma, malignant Brenner tumor, and clear cell carcinoma which develop slowly in a stepwise fashion from well-recognized precursors, namely atypical proliferative (borderline) tumors. Type II tumors are high-grade, rapidly growing tumors that typically have spread beyond the ovaries at presentation. They include high-grade serous carcinoma ("moderately" and "poorly" differentiated), malignant mixed mesodermal tumors (carcinosarcomas), and undifferentiated carcinoma. These tumors are rarely associated with morphologically recognizable precursor lesions and it has been proposed that they develop "de novo" from ovarian inclusion cysts. This model implies that the pathogenesis of type I and type II tumors are separate and independent but it is not clear whether some type II tumors develop from type I tumors. In this study, we attempted to address this issue by determining the clonality of 6 cases of high-grade serous carcinomas that were closely associated with atypical proliferative serous (borderline) tumors and invasive low-grade micropapillary serous carcinomas. We reviewed 210 ovarian serous tumors from the surgical pathology files of the Johns Hopkins Hospital and identified 3 high-grade serous carcinoma that were directly associated with atypical proliferative serous (borderline) tumors and 3 that were associated with invasive low-grade micropapillary serous carcinomas. A morphologic continuum between the high-grade carcinoma and the low-grade tumors was observed in 4 cases whereas in the remaining 2 cases the high-grade and low-grade components were separate. Mutational analyses for KRAS, BRAF, and p53 genes were performed on microdissected samples from the high-grade and low-grade tumor areas for each case. All 6 tumors demonstrated wild-type BRAF and p53 genes. Only 2 of the 6 cases were informative from a molecular genetic standpoint. In those 2 cases we found the same mutations of KRAS in both the atypical proliferative serous (borderline) tumor and the high-grade serous carcinoma component of the tumor, indicating a clonal relationship. The above results suggest that the majority of high-grade and low-grade carcinomas develop independently but in rare cases, a high-grade serous carcinoma may arise from an atypical proliferative serous (borderline) tumor.

Hepatoid Carcinoma With Serous Component of the Fallopian Tube

A very rare case of hepatoid carcinoma with serous component arising in the fallopian tube of a 79-year-old woman is presented. The lesion was a 5.0-cm unencapsulated, yellowish-white soft mass. The tumor was composed of hepatoid carcinoma (90%) and serous carcinoma (10%) components. The hepatoid carcinoma was histologically characterized by a proliferation of round to polygonal cells arranged in a trabecular, tubular, sinusoidal, papillary, or solid pattern. The serous component in the fallopian tube also showed in situ lesions. Both components showed an infiltration into the surface of the left ovary, omentum, peritoneum including the pouch of the Douglas, and serosa of the colon. Immunohistochemically, the hepatoid carcinoma was positive for alpha-fetoprotein, polyclonal carcinoembryonic antigen (CEA), hepatocyte paraffin 1, albumin, epithelial membrane antigen, and cytokeratin (CAM5.2). Ultrastructurally, the cytoplasm contained abundant ribosomes, moderate amounts of mitochondria, and rough endoplasmic reticulum that developed into a meshwork and contained mitochondria within it. Microbile channel-like structures and desmosomes were occasionally observed. The association with serous carcinoma indicates mullerian origin rather than germ cell origin. The patient received chemotherapy and was alive without disease at 10 months after surgery.

Serous Carcinoma of the Endometrium with Choriocarcinomatous Differentiation

Nongestational choriocarcinomas rarely occur outside the gonads or teratomas. We report a serous carcinoma of the endometrium with a choriocarcinomatous component and review of the literature. A 61-year-old woman underwent hysterectomy and bilateral salpingo-oophorectomy for a serous carcinoma with choriocarcinomatous component. Immunohistochemistry showed a strong p53 staining of the serous component and the cytotrophoblastic cells of the choriocarcinomatous component; the syncytiotrophoblast was negative. The initial serum human chorionic gonadotropin (hCG) was 225,000 IU/L. Postoperatively, the patient developed diffuse pulmonary metastatic disease. Despite chemotherapy, the patient died 2 months after initial diagnosis. Abstracting the data from the reported cases and from the literature, it can be assumed that 2 different tumor types exist. The first one is morphologically and clinically more related to the gestational choriocarcinoma with strongly elevated serum hCG levels, early onset of (distant) metastatic disease, and consecutively rapid and often fatal clinical course. The second type presents as an endometrial carcinoma with single syncytiotrophoblast-like cells, associated with low serum hCG, no distant metastatic disease, and, consequently, a better prognosis. The prognostically relevant component for long-time survival in the latter variant is the nontrophoblastic component.

The development of endotension is associated with increased transmission of pressure and serous components in porous expanded polytetrafluoroethylene stent-grafts: Characterization using a canine model

This study used a canine model of abdominal aortic aneurysms (AAAs) to compare intra-aneurysmal pressure and thrombus formation after exclusion with Dacron and expanded polytetrafluoroethylene (ePTFE) stent-grafts. Prosthetic AAAs with implanted strain-gauge pressure transducers were treated by stent-graft exclusion using Food and Drug Administration-approved devices in 10 mongrel dogs: five Dacron (AneuRx) and five ePTFE (original Excluder). Intra-aneurysmal pressure was measured over 4 weeks after AAA exclusion and indexed to the systemic pressure, represented as a percentage of a simultaneously obtained systemic pressure (value = 1.0). Magnetic resonance imaging (MRI) of the intra-aneurysmal thrombus was performed at 1, 2, and 4 weeks after exclusion and expressed as a signal-to-noise ratio (S:N) to control for background signal intensity. Comparisons of pressures and S:N between the two stent-grafts was analyzed with the Student's t test. Intra-aneurysmal thrombus was characterized histologically. In animals excluded with both Dacron and ePTFE stent-grafts, the intra-aneurysmal pressure was nonpulsatile and reduced to <30% of systemic pressure. Significantly greater pressure transmission was observed after AAA exclusion using ePTFE compared with Dacron stent grafts (systolic pressure: ePTFE, 0.28 +/- 0.12 vs Dacron, 0.11 +/- 0.02, P < .001; mean pressure: ePTFE, 0.16 +/- 0.08 vs Dacron, 0.06 +/- 0.02, P < .001). MRI confirmed the absence of perfusion in all aneurysms. The T1-weighted signal intensity remained persistently elevated (S:N at 1 week, 2.7 +/- 0.4 vs 2 weeks, 4.0 +/- 0.2 vs 4 weeks, 5.4 +/- 1.3) in ePTFE-treated intra-aneurysmal thrombus, suggesting an absence of thrombus organization. In contrast, progressive evolution of T1 signal intensity in aneurysms excluded by Dacron stent-grafts was consistent with maturation from intact red blood cells (S:N at 1 week, 3.3 +/- 0.4) to methemoglobin (S:N at 2 weeks, 6.1 +/- 0.8), and then hemosiderin and ferritin (S:N at 4 weeks, 2.4 +/- 0.5). Histologically, ePTFE-excluded aneurysms contained poorly organized thrombus with red blood cell fragments and haphazardly arranged fibrin deposition indicative of active remodeling and continued influx of transudated serum. In aneurysms excluded by Dacron stent-grafts, dense, mature collagenous connective tissue and organized fibrin were present, indicative of greater thrombus organization. Stent-graft treatment reduces intra-aneurysmal pressure to <30% of systemic pressure when no endoleak is present; however, significantly greater pressure is present in aneurysms treated with porous ePTFE stent-grafts than Dacron grafts. Histologic and MRI imaging analysis suggest that active transudation of serous blood components may be contributing to this increased intra-aneurysmal pressure.

Endometrial carcinoma in one horn of a bicornuate uterus

Background. Tamoxifen therapy is related to endometrial adenocarcinoma. Bicornuate uteri are more common than assumed. There are a few reports of endometrioid carcinoma arising in a bicornuate uterus, but none of these discuss a serous papillary component or an association with tamoxifen therapy. Case. This is a case of a mixed endometrioid and serous papillary endometrial carcinoma arising in one horn of a bicornuate uterus. Multiple benign polyps were also present. Conclusion. Adequate tissue sampling of both horns is critical to arriving at a timely and accurate diagnosis of malignancy in patients with a bicornuate uterus.