[1028] Atypical Leiomyomas of the Uterus: A Clinicopathologic Study of 46 Cases

A Ly, JK McKenney, TA Longacre, RL Kempson, MR Hendrickson. Stanford University Hospital, Stanford, CA

Background: Atypical leiomyoma is a well-described smooth muscle neoplasm of the uterus. Only one study has addressed long-term clinical follow-up in a large series, and little is known about the adequacy of treatment by myomectomy.
Design: The surgical pathology archives were searched for consecutive cases of uterine atypical leiomyoma from 1992 to 2003. Glass slides were reviewed to confirm the diagnoses (Bell et al.) and patient age, treatment modality, and clinical follow-up data were recorded.
Results: 46 atypical leiomyomas with available glass slides and clinical follow-up were identified. 24 tumors exhibited diffuse, moderately to severely atypical cells, whereas 22 showed atypical cells in a more patchy distribution. 11 had ischemic-type necrosis. By highest count method, 34 cases had 1 MF/10 HPF, 11 showed 1-3 MF/10 HPF, and 1 was nearly entirely necrotic precluding mitotic assessment. Where adjacent non-neoplastic tissue was well-visualized, all had pushing margins (43 cases). The average tumor size was 6.8 cm (median 6.5 cm, range 0.7-14 cm). The average patient age was 42.5 years (median 42 years, range 21-72 yrs). 30 were treated with hysterectomy, and 16 with myomectomy. Average follow-up was 42 months (range 0.3-121.8 months). Of those treated with hysterectomy, 1 had recurrent atypical leiomyoma in the retroperitoneum at 87.5 months, 1 died of other causes, and all 28 others (93%) were free of disease. Of the myomectomy group, 2 had residual atypical leiomyoma in the subsequent hysterectomy specimen, and 1 underwent second myomectomy for atypical leiomyoma with 2 subsequent successful pregnancies. All 13 others (81%) were clinically free of disease.
Conclusions: Atypical leiomyoma has a low rate of extrauterine, intra-abdominal recurrence (2%) with no apparent risk for distant metastasis. Patients may be treated by myomectomy alone with successful pregnancy, but should be monitored for local intrauterine residual/recurrent disease (19% in this study).
Category: Gynecologic

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 158, Monday Morning