Atypical leiomyomas of the uterus with long-term follow-up after myomectomy with immunohistochemical analysis for p16INK4A, p53, Ki-67, estrogen receptors, and progesterone receptors.

Atypical leiomyomas are characterized by moderately to severely pleomorphic atypical tumor cells with low mitotic counts and no coagulative tumor cell necrosis. Despite the worrisome histologic features, most tumors have shown benign behavior. However, most studied patients had total hysterectomies, and very few patients who had myomectomy alone have had long-term follow-up. The behavior of atypical leiomyomas treated with myomectomy alone is still not known. We present a study of 13 atypical leiomyomas treated with myomectomy alone with long-term follow-up results and immunohistochemical findings for p16 (p16), p53, Ki-67, estrogen receptors, and progesterone receptors. The lengths of the postoperative intervals ranged from 20 to 151 months (mean=76.1 mo). None of the patients had developed a metastasis of her atypical leiomyoma. However, 1 patient showed local recurrence at the past myomectomy site 22 months after initial myomectomy. Immunostaining for p16 showed moderate to strong diffuse immunoreactivity in 11/13 cases (84.6%) of atypical leiomyomas, and 38.5% showed immunoreactivity for p53, including 1 case with strong, diffuse positive p53. When an atypical leiomyoma is discovered in a myomectomy specimen, the patient should be carefully followed up with or hysterectomy could be recommended. Larger numbers of cases and more long-term follow-up studies are needed to confirm the safety of myomectomy for atypical leiomyomas.