Pathological Features And Correlation Analysis Of Low Grade Endometrial Endometrioid Carcinoma With Different Myometrial Invasion Patterns

Background and objectivesEndometrial carcinoma is one of the most common malignant tumors in women,and endometrioid carcinoma is the most common pathological subtype.Low grade endometrioid carcinoma usually has a good prognosis,however,recurrence and metastasis occur in some patients.The prognosis of endometrioid carcinoma is affected by a variety of factors,including histological grade,depth of myometrium invasion and so on.The patterns of myometrial invasion could also affect the prognosis of this cancer,although which has not been fully understood.Endometrioid carcinoma demonstrates a variety of myometrial invasion patterns,including infiltrating glands,broad front,adenomyosis like,adenoma malignum and microcystic,elongated and fragmented(MELF).The relationship between the patterns and some prognostic factors has been studied,although the number of studies was less and most of the studies were concentrated on the MELF pattern only.On the other hand,few studies discussed about the relationship between the patterns and expression of biomakers.In the present study,we reviewed the histological sections of low grade endometrioid carcinoma(grade 1 and 2),analysed the myometrial invasion patterns,pathological features and the expression of estrogen receptor(ER),progesterone receptor(PR)and Ki67,and explored whether the patterns of myometrial invasion could be a potential factor associated with the prognosis of this cancer.Materials and methodsIn total,175 cases of low grade endometrioid carcinoma with myometrialinvasion were selected from archival files in the Department of Pathology,The Second Hospital of Jilin University.Main pattern of myometrial invasion,appearance of MELF pattern and some other pathological features were recorded.Meanwhile,immunohistochemistry staining of ER,PR and Ki67 was performed and the results were collected.Statistical analyses were used to discover the relationship between the myometrial invasion patterns,pathological features and the expression of biomakers.Results1.Infiltrating glands pattern demonstrated the highest frequency of 45.1% among the cases reviewed,broad front pattern and adenomyosis like pattern shared 29.7% and 25.2% respectively.Cases with adenoma malignum pattern or MELF pattern in main were not appearing.2.Among the groups of infiltrating glands,broad front and adenomyosis like,the frequency of deeper myometrial invasion and vascular invasion in broad front pattern were different statistically from the frequency of the other two patterns(p <0.0167).On the other hand,the distribution of patients’ ages and the frequency of pelvic lymphnode metastasis showed statistical difference between infiltrating glands pattern and broad front pattern(p <0.0167).3.Among the cases reviewed,appearance of MELF pattern demonstrated a frequency of 41.1%,which shared 50.6%,17.3% and 52.3% in the group of infiltrating glands,broad front and adenomyosis like respectively.The frequency of MELF pattern in broad front pattern were different statistically from the frequency of the other two patterns(p <0.0167).4.The frequency of histological grade 1,deeper myometrial invasion,vascular invasion,pelvic lymphnode metastasis and the distribution of patients’ ages and FIGO stage showed statistical difference between MELF-positive and MELF-negative cases(p <0.05).5.When the cases were analysed in the groups of MELF-positive and MELF-negtive seperately,no statistical difference was observed among the 3 patterns of endometrioid carcinoma(p >0.05).6.The presence of MELF pattern is associated with some adverse pathological features such as vascular invasion in any single pattern of infiltrating glands,broad front or adenomyosis like(p >0.05).7.Among the groups of infiltrating glands,broad front and adenomyosis like,the expression of ER,PR and Ki67 showed no statistical difference(p >0.05).8.The positive rate of ER,PR and Ki67 showed no statistical difference between MELF-positive and MELF-negative cases(p >0.05).Conclusions1.Infiltrating glands pattern demonstrated the highest frequency in low grade endometrioid carcinoma.2.MELF-positive cases are more likely to have an elder age,higher histological grade,deeper myometrial invasion,vascular invasion,pelvic lymphnode metastasis and advanced FIGO stage,which indicates that MELF-positive cases could have a worse prognosis than MELF-negative cases.3.Tumors with broad front pattern are inclined to have a younger age,invase the inner half of myometrium and demonstrate neither vascular invasion nor pelvic lymphnode metastasis;these features are accociated with its lower frequency of MELF appearence.These results indicate that broad front pattern could have a better prognosis.4.The positive rate of ER,PR and Ki67 shows no statistical difference among the groups of infiltrating glands,broad front and adenomyosis like,or between MELF-positive and MELF-negative cases.