[1187] Histologic Patterns of Myometrial Invasion in FIGO Grade 2 Endometrioid Endometrial Adenocarcinoma

Douglas I Lin, Whitney M Winham, Pamela J Stone, Charles M Quick, Marisa R Nucci. Brigham & Women's Hospital, Boston, MA; UAMS, Little Rock, AR

Background: Endometrioid adenocarcinoma of the endometrium (EEC) is the most common histologic type of endometrial cancer; however few studies have evaluated the importance of patterns of myometrial invasion. Therefore, we were interested in evaluating this parameter in cases of grade 2 EEC and correlating it with clinical outcome.
Design: 68 cases of grade 2 EEC (January 2002 - September 2009), with at least 2 years of clinical followup were retrieved from our files and reviewed to identify those with myoinvasion. Myoinvasion was subclassified into the following patterns: infiltrating glands (IG), broad front, adenomyosis-like, microcystic elongated and fragmented glands (MELF), and adenoma-malignum. Depth of invasion and presence/absence of lymphovascular invasion were confirmed, and clinical follow up was obtained.
Results: 56/68 (82%) cases of grade 2 EEC were myoinvasive. Of these, 11 (20%) were superficially invasive (<10% myoinvasion), 28 (50%) invaded 10-49%, and 17 (30%) invaded >50% into the myometrium. The invasive patterns consisted of IG (32; 57.1%), both IG and a second minor component of MELF (4, 7.1%), broad front (11; 19.6%), MELF alone (3, 5.4%), adenomyosis-like (6; 10.7%). No cases of adenoma malignum-like pattern of invasion were identified. Lymphovascular invasion was noted in 21 cases (30.9%); 15 (71%) of which had IG. 11 (16.2%) cases contained cervical stromal invasion; 8 (72%) of which had IG. Six (8.8%) patients had hysterectomy and bilateral salpingo-oophorectomy while sixty-two (91.2%) also underwent a lymphadenectomy (LND). Forty-five (66.2%) patients received adjuvant therapy (chemotherapy, radiation therapy, or vaginal brachytherapy). 6/62 patients with LND had metastases; 4/6 (66%) had IG. None of the cases without myoinvasion recurred while 8 (14.3%) cases with myoinvasion recurred (follow-up mean: 45 months). Of the patients with recurrence, all had an IG (including one case with a minor MELF component).
Conclusions: In this series, the majority of patients with grade 2 EEC had myometrial invasion (56/68; 82%) which is in distinct contrast to our previous study (Mod Path 24 (1), 2011; 264A, Abstract 1119) where 30% of Grade I cases were invasive. The presence of infiltrative gland pattern of myoinvasion is associated with recurrence and other pathologic variables of poor outcome including LVI, cervical stromal invasion and lymph node involvement.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 173, Tuesday Morning

 

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