[1214] Histopathologic Changes in Progesterone-Treated Endometrial Hyperplasia and Carcinoma

Lorraine Y Pan, Ann K Folkins, Teri A Longacre. Stanford University, Stanford, CA

Background: Endometrial carcinoma is the most common gynecological malignancy. For pre-menopausal patients with complex atypical hyperplasia and well-differentiated endometrial adenocarcinoma, there are alternative therapies to definitive hysterectomy. Previous studies have described the morphologic changes associated with progesterone therapy. This study endeavors to further characterize treatment effect to aid in the evaluation of post-therapy endometrial samples.
Design: 70 cases of endometrial proliferation (including simple hyperplasia, complex hyperplasia, complex atypical hyperplasia, and endometrioid adenocarcinoma) with samples from before and after progesterone therapy were identified from 1/1/2001 to 9/1/2012. The reports from these cases were used to identify treatment-related morphologic findings. We then examined seven cases (three with material before and after treatment and four with only post-therapy material) for the presence of these morphologic findings.
Results: Of the 70 cases, 57 retained a complex architecture and 28 retained significant nuclear atypia. The most common forms of metaplasia identified included morular/squamous (23/70, 33%), mucinous (19/70, 27%), eosinophilic (13/70, 19%), and secretory-like (11/70, 16%). A small number demonstrated cribriform (12/70, 17%) and papillary (8/70, 11%) architecture in the post-treatment biopsies. 4 of the 69 cases showed solid architecture. The treatment regimens included oral progestogens (38/70, 54%), progesterone IUD (7/70, 10%), and combination oral and IUD therapy (6/70, 9%). Of the seven cases with post-treatment biopsies, 5 demonstrated complex architecture. One case retained the pre-treatment nuclear atypia. Interestingly, mucinous metaplasia was seen in 5 of 7 cases, 3 of which had pre-treatment biopsies without mucinous change. Almost all of the cases showed eosinophilic metaplasia (6 of 7). Tubal and morular metaplasia were also noted.
Conclusions: We confirm that metaplasias and resolution of atypia are associated with progesterone-treated hyperplasia and carcinoma. In our study, mucinous metaplasia was associated with therapy, as it was present in post-treatment biopsies but not in the pre-treatment biopsies examined. Secretory-like change was also noted in some cases following treatment. Although it is important to consider an underlying malignant process, such as a low grade mucinous carcinoma or a clear cell carcinoma, it should be recognized that these cytologic changes are common following progesterone therapy. Recognition of the spectrum of changes can assist in the evaluation of progesterone-treated endometrium.
Category: Gynecologic & Obstetrics

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 182, Monday Morning


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