Atypical Leiomyomas of the Uterus: A Clinicopathologic Study of 54 Cases and Immunohistochemical Analysis of Ki-67 (MIB-1) and p53.

Objective Uterine atypical leiomyomas (AL) are extremely rare, and occurs a decade earlier than the onset of leiomyosarcoma. According to the literature, extensive clinicopathologic studies on AL are limited to only two studies. Atypical leiomyomas of uterus are well-defined neoplasms with smooth muscle cells. The aim of this study was to investigate clinicopathologic findings in 54 cases with Atypical Leiomyoma diagnosis and Ki-67 and p53 expressions immunohistochemically. Methods Fifty-four cases diagnosed between 2000 and 2013 were included. The histological and clinical features of the cases were revised and their medical records were examined. Ki-67 and p53 were performed on all cases immunohistochemically. Results The average age of cases was 41.8 years. The average clinical follow-up period was 57 months. Hysterectomy was performed in 31 cases, and myomectomy was performed in 21 cases, while resection of the mass was performed in two patients due to the intraligamenter mass. The average size of the neoplasms was 6.2 cm. Severe cellular atypia was noticed in 25 patients. While the number of mitoses was 1/10 HPF in 30 cases, it was 4/10 HPF in six of them. Ki-67 was found positive in 50 cases at the rate of 1-5% immunohistochemically, while p53 has demonstrated staining at the ratio of 10-15% staining in four patients. Conclusion The differential diagnosis of atypical leiomyomas from leiomyosarcomas is crucial. The recurrence rate after follow-up is 2%. In our opinion, the cases diagnosed with 'atypical leiomyoma with limited experience' before should be correctly diagnosed with atypical leiomyoma. We recommend that Ki-67 and p53 can be used as an adjuvant marker immunohistochemically in the cases that problem in differential diagnosis from Leiomyosarcoma exist.