Objective: A pattern-based classification system, Silva classification system, stratifies endocervical adenocarcinomas into 3 categories that present to correlation of lymph node metastasis. The aim of this study was to evaluate whether the Silva system is applicable to all endocervical adenocarcinoma including usual and unusual type, to suggest a suitable management plan of endocervial adenocarcinoma. Methods: In this retrospective study, we retrieved consecutive pathology cases with a final diagnosis of endocervical adenocarcinoma treated with radical hysterectomy and bilateral pelvic lymphadenectomy. Specimens were classified by consensus according to the Silva system based on pattern of invasion as A, B, or C. And clinical/pathologic features assessed: tumor histology, depth of invasion (mm), tumor size, histologic grade, LVI, LN metastases, stage, recurrence, survival and complications after surgery according to pattern based classification. Results: A total of 76 cases of invasive cervical adenocarcinoma were evaluated and 63 (82.9%) were categorized in endocervical adenocarcinoma, usual type and 13 cases (17.1%) were special types. All endocervical adenocarcinoma with pattern A revealed the good prognosis, as in usual type, unusual types also had no lymph node meatstasis, no LVI, and no recurrence in pattern A tumors. Although pattern A tumors had no LN metastasis but they had the complications after surgery such as pattern B or C tumors. In our study, LN metastasis and pattern C tumors remained significant an independent predicator of DFS (HR, 11.17; 95% CI, 3.08-40.48 and HR, 4.81; 95% CI, 1.12-20.60, respectively). Conclusion: Regardless of histologic subtypes, pattern A tumors had no LN metastasis and no recurrence. So the pattern-based classification can influence clinical management decision of all endocervical adenocarcinoma. Conservative approach is possible to patients with pattern A tumors but aggressive management is justified in patients with pattern C tumors. Acknowledgements: This work was supported by 2017 Inje University Busan Paik Hospital research grant.