A Clinicopathological Study Of Ovarian Mucinous Tumors

Background and Objective Primary ovarian mucinous tumors (primary mucinous tumors, PMT), which has complicated origin and multiplex morphousis, is common in ovarian epithelial tumors. Owing to one of the best sites of tumor metastasis, metastatic mucinous neoplasms (MMN) of ovary may be the first symptom while its primary tumor is hiding. In addition, MMN is in the form of seemingly benign, borderline or malignant tumor and is easily be misdiagnosed. Thus, it is very important for differential diagnosis between PMT and MMN because misdiagnosis would lead to serious consequences. The purpose of this study is to investigate the differential diagnosis between PMT and MMN from clinicopathological and immunohistochemical features. Methods Firstly,155 cases of ovarian mucinous tumors between April 2009 and January 2015 from the department of pathology of Anhui Provincial Hospital and Anhui Provincial Cancer Hospital were recruited. Each sample was 10% formalin-fixed, paraffin-embedded, and haematoxylin and eosin (HE)-stained. Secondly,155 cases were divided for two groups, which were PMT group and MMN group, according to the newly published "WHO classification of tumors of female genital mutilation" in 2014. 128 cases in PMT group contained 86 benign cases,31 borderline cases and 11 malignant cases. In 27 cases of MMN group,19 cases were originated from appendix,5 cases from colon,1 case from pancreas and 2 cases from cervix. Thirdly, immunohistochemical staining was performed to investigate the expression of CK7, CK20, MUC-1, MUC-2, CDX-2 and Villin in these two groups. Lastly, all data would be counted by statistics software and clinicopathological parameters which were diagnostic value would be explored. Results The patient which is more than 40 years old, with bilateral lesions and peritoneal pseudomyxoma (Pseudomyxoma peritonei, PMP) is more common in the MMN group (P<0.05). Compared with MMN group, the expression of CK7 and MUC-1 were upregulated, while the expression of CK20, MUC-2 and CDX-2 were decreased in the PMT group (P<0.05). The expression of Villin between these two groups was not statistically significant (P> 0.05). Conclusion It would be considered as PMT when clinical data showed that the patient was younger than 40 years old, with unifocal lesion and diffuse strong positive expressions of CK7/MUC-1, but without PMP. On the other hand, when the patient was more than 40 years old, with bilateral lesions, PMP and diffuse strong positive expressions of CK20/MUC-2/CDX-2, MMN from the lower digestive tract would be considered firstly after excluded from the intestinal mucinous tumors of ovarian teratoma. Besides, when these markers were crossed, it would be combined clinicopathological features and if necessary, general check-up would be performed to exclude the possible metastasis. Therefore, the differential diagnosis of PMT and MMN is so complex that it requires a combination of clinical, morphological and immunohistochemical results to judge.