[Microcystic, elongated and fragmented invasion pattern in endometrial carcinoma: the clinicopathology analysis]

Objective: To assess the clinical value for the clinicopathological features of microcystic elongated and fragmented (MELF) invasion in endometrial carcinoma (EEC) . Methods: The clinicopathological data of 108 cases of endometrial carcinoma with total hysterectomy, bilateral adnexectomy, and pelvic dissection were retrospectively analysis in Peking University People's Hospital from April 2015 to October 2016. Twenty-five patients with endometrial carcinoma showing MELF invasion pattern were collected. We analyzed retrospectively the association of MELF pattern invasion with clinical pathology data and prognosis of the patients, partial immunohistochemical staining was implemented. MELF invasion was a special invasion pattern and characterized by microcystic, elongated, fragmented (composed of cluster cells) gland in muscular layer. Results: The incidence rate was 23.1% (25/108). These patients mean age was (59.3±10.9) years old. Four cases were premenopausal, and 21 were postmenopausal. Abnormal vaginal bleeding was the main clinical presentation. The lesions tend to appear adjacent to the tumor body. Sometimes, it may be appears away from the tumor body in the deep muscle layer.Lymph node metastasis were present in 5 cases (20%, 5/25). Thirteen cases (52%, 13/25) of them demonstrated lymph vascular space involvement (LVSI). The immunohischemical expression of ER,PR, Ki-67 and galectin-3 showing MELF invasion pattern were weaker than no showing MELF invasion pattern endometrial carcinoma, cktokeratin (CK) was showed diffuse strong positive expression, E-cadherin was moderately positive expression. All 25 cases were followed up for (23.2±5.9) months (14-33 months) after the therapy with no recurrence on metastasis. Conclusions: MELF invasion pattern is a special invasion pattern in low-grade EEC. The incidence of LVSI and lymph node metastasis rate in endometrial carcinoma with MELF invasion are significantly increased. The prognosis of MELF invasion pattern may be poor.