Ovarian seromucinous carcinoma: an independent epithelial ovarian cancer?

BACKGROUND: 2020 World Health Organization Classification of Female Genital Tumors removed ovarian seromucinous carcinoma as a distinct entity and recategorized it as ovarian endometrioid carcinoma with mucinous differentiation according to its pathological features. The aim of this study was to find whether ovarian seromucinous carcinoma truly represented a distinct category of ovarian tumors or an analogue of ovarian endometrioid carcinoma. METHODS: Twelve patients diagnosed with ovarian seromucinous carcinoma and received surgery at the Xiangya Hospital from January 2010 to December 2019 were included in this study. Clinicopathological features such as clinical symptoms, serological indicators, surgical information, postoperative findings, chemotherapy sensitivity, follow-up information, HE staining and IHC staining images and other clinicopathologic features were collected. Using t-test and Kaplan Meier to perform statistical analysis. Pathological review was conducted using the 2014 World Health Organization criteria. All pathological diagnoses were reviewed by two experienced pathologists. RESULTS: The age of 12 patients diagnosed with ovarian seromucinous carcinoma ranged from 23 to 68 years, with a median age of 46.8 years. Serum level of CA125 was elevated in 10 patients, and CA125/CEA ratio was less than 25 in 6 patients. Eleven patients underwent radical ovarian cancer surgery, and one patient underwent fertility preservation surgery. The progression free survival and overall survival of ovarian seromucinous carcinoma is 46.8 months and 50.2 months. Kaplan-Meier survival curve showed that the prognosis of ovarian seromucinous carcinoma and ovarian endometrioid carcinoma was significantly different (P = 0.03). The prognosis of ovarian seromucinous carcinoma and ovarian mucinous carcinoma was similar. CONCLUSION: Although ovarian seromucinous carcinoma and ovarian endometrioid carcinoma are similar in pathologic morphology, their clinical features and prognosis are significantly different. The signs, serum biomarker and prognosis of the ovarian seromucinous carcinoma are similar with ovarian mucinous carcinoma. Therefore, ovarian seromucinous carcinoma is not suitable to be directly classified as ovarian endometrioid carcinoma.

Synchronous Occurrence of Ovarian Seromucinous Carcinoma and Endometrial Mucinous Carcinoma: A Case Report.

Endometrioid carcinoma is the most common histological type of concurrent synchronous cancers of the uterus and ovary. Here we report a case of synchronous seromucinous carcinoma of the ovary and mucinous carcinoma of the endometrium with a literature review. A 51-year-old multiparous female complained of irregular bleeding and shortness of breath. Computed tomography revealed a large pelvic mass that consisted of cystic and solid components, a tumor of the endometrium, and a large amount of pleural effusion. An endometrial biopsy indicated adenocarcinoma, and adenocarcinoma cells were found in the pleural fluid. The patient with advanced ovarian cancer or endometrial cancer with massive pleural effusion received three courses of neoadjuvant chemotherapy (NAC) with paclitaxel and carboplatin followed by interval debulking surgery (IDS). The NAC was effective, and IDS was performed with no gross residual lesions. The post-operative diagnosis was seromucinous carcinoma of the ovary in FIGO (2014) stage IVA (ypT3cNxM1a) and mucinous carcinoma of the endometrium in FIGO (2008) stage IA (ypT1aNXM0). Three courses of postoperative TC therapy were performed, and maintenance therapy with Bevacizumab is ongoing. The patient is well without evidence of recurrence, sixteen months after surgery.

Ovarian seromucinous tumors: clinicopathological features of 10 cases with a detailed review of the literature.

BACKGROUND: The 2014 WHO Classification of ovarian neoplasms introduced a new entity of seromucinous tumors associated with endometriosis. These tumors encompassed a spectrum from benign to malignant and included seromucinous cystadenoma/ cystadenofibroma, seromucinous borderline tumor/atypical proliferative seromucinous tumor and seromucinous carcinoma. However, the 2020 WHO Classification of Female Genital Tumours removed seromucinous carcinomas as a distinct entity and recategorized them as Endometrioid carcinomas with mucinous differentiation. Here we describe clinico-morphologic features of seromucinous tumors recategorizing cases originally diagnosed as seromucinous carcinoma in light of 2020 WHO classification and present detailed review of literature. METHODS: Slides of seromucinous tumors were reviewed. Special emphasis was given to evaluation of stromal invasion. Follow-up was obtained. RESULTS: Ten cases were diagnosed. Mean age was 40 years. Four cases were bilateral. Mean size was 19 cm. Grossly; luminal papillary projections were seen in 6 cases. Tumors demonstrated a papillary architecture with papillae lined by stratified seromucinous epithelium showing nuclear atypia. Stromal invasion was seen in 4 cases. Six cases were reported as borderline seromucinous tumors and 4 cases originally diagnosed as seromucinous carcinoma were recategorized as endometrioid carcinoma with mucinous differentiation on review. Endometriosis was seen in 4 cases. CK7, PAX8 and ER were positive in 7/7 cases. Two cases showed extra-ovarian involvement. Follow up was available in 7 cases. Six patients were alive and well at follow up ranging from 8 to 46 months. Six patients received chemotherapy postoperatively. One patient with carcinoma died of disease 18 months postoperatively. CONCLUSION: In our series, 4 cases were originally diagnosed as seromucinous carcinomas. However, these were recategorized in light of the 2020 WHO Classification of Female Genital tumors as endometrioid carcinomas with mucinous differentiation. Six cases were diagnosed as seromucinous borderline tumors. Thus, majority of cases were borderline in agreement with published literature.

Three cases of seromucinous carcinoma of the ovary arising in endometriotic cysts.

Ovarian seromucinous carcinoma (SMC) is an uncommon neoplasia and is composed predominantly of serous and endocervical-type mucinous epithelium. Due to its low frequency and difficult diagnosis, the natural history, characteristic imaging findings, and pathological features of SMC have not been adequately described in the literature thus far. We herein report three cases of ovarian SMC along with magnetic resonance imaging (MRI) findings. The diagnosis of SMC was made after staging laparotomy in all cases, and systemic chemotherapy was performed in two cases. No recurrence was observed in any of the cases. The MRI findings in SMC were so varied that characteristic imaging features useful for diagnosis were not found. In two cases, MRI suggested endometriotic cysts, and endometriosis and seromucinous borderline tumors (SMBTs) were detected concurrently in all cases by histological examination. Thus, it was suggested that SMC develops in multiple stages via endometriosis and SMBT. The cooccurrence of endometriosis and SMBT could also make the diagnosis of SMC more convincing.

Metachronous occurrence of two different histological subtypes of endometriosis-related neoplasms.

A solitary pelvic tumor after treating a primary endometriosis-related neoplasm is usually considered a recurrence but may actually be a primary endometriosis-related peritoneal neoplasm. A Japanese woman in her late 60s was referred to our hospital for a solitary pelvic tumor. The tumor was suspected as a recurrence of a previously treated stage IA ovarian clear-cell carcinoma, and resected. Pathological analysis revealed that the tumor was a peritoneal seromucinous carcinoma associated with pelvic endometriosis. Both tumors displayed distinct histopathologies, although both neoplasms were endometriosis related. An apparent recurrent tumor after treating of an endometriosis-related neoplasm might not be a true recurrent tumor but a second primary endometriosis-related neoplasm. Histological confirmation is indicated in such cases.