[1136] Atypical Polypoid Adenomyoma (APA) of the Uterus: A Clinicopathologic Study of 50 Cases

Masaharu Fukunaga, Takashi Matsumoto, Tsunehisa Kaku, Atsuhiko Sakamoto, Hitoshi Tsuda. Jikei University Daisan Hospital, Tokyo, Japan; Shikoku Cancer Center, Ehime, Japan; Kyushu University, Fukuoka, Japan; National Cancer Center, Tokyo, Japan; Kyorin University, Tokyo, Japan

Background: APA has been regarded as a benign tumor; however, it is often associated with endometrioid adenocarcinoma and its histologic diagnosis and biologic potential have been controversial.
Design: A multicentric study was carried out involving 15 institutions in Japan. Clinicopathologic features, morphology, and the effects of hormonal (medroxyprogesterone acetate) therapy and biologic behavior were studied in 50 APA cases.
Results: The patients' ages ranged from 22 to 66 (mean: 30) years. All but three of the patients were premenopausal. Histologically, the lesions were composed of a biphasic proliferation of architecturally complex and cytologically atypical endometrial glands with a myomatous or myofibromatous stroma. Squamous metaplasia or morules were observed in 37 cases. Eleven had evidence of background endometrial hyperplasia and 15 had endometrioid carcinoma (12 in APA and 3 in the adjacent endometrium). All 6 patients who were initially treated with curettage or polypectomy followed by hormonal therapy had residual or recurrent APA. Cases treated with hormonal therapy exhibited a decreased N/C ratio of epithelial cells, persistent atypical glandular structures, and a markedly edematous stroma. Hysterectomy was performed in 13 cases because a definite diagnosis could not be made preoperatively, the curettages raised the possibility of adenocarcinoma, or because there was a high possibility of residual or recurrent lesions. All showed residual or recurrent APA in hysterectomy specimens. Two showed superficial myometrial invasion, and two showed APA in a focus of adenomyosis. The overall residual or recurrent lesion rate was high (19/50, 38%). All patients were alive and well at 1 to 202 months (mean, 39.6 months).
Conclusions: The rate of recurrent or residual APA was high, and the effects of hormonal therapy were limited. The risk of endometrial carcinoma in women with APA is also high. This study suggests that APA should be carefully evaluated and cannot be automatically regarded as a totally benign entity. The findings indicate a continued risk for the development of endometrial adenocarcinoma in patients in whom complete excision of APA can not be guaranteed. If a confident diagnosis of APA has been made on curettage or polypectomy, hysterectomy is the treatment of choice. However, treatment by complete curettage or polypectomy may be undertaken, thereby, preserving the reproductive function, providing there is subsequent close follow-up.
Category: Gynecologic & Obstetrics

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 195, Wednesday Afternoon

 

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