Departments of Pathology and Obstetrics and Gynecology, Yeungnam University, College of Medicine, Daegu 705-035, Korea. mjkap@med.yu.ac.kr
ABSTRACT
BACKGROUND: Controversy still remains concerning the criteria for the categorization of uterine smooth muscle tumors by conventional histologic examination. Various ancillary techniques have been used to improve diagnostic accuracy.
METHODS: Immunohistochemical study of MIB-1 and p53 was performed on 10 usual leiomyomas (UL), 13 cellular leiomyomas (CL), 5 bizarre leiomyomas (BL), 2 cases of intravenous leiomyomatosis (IL), 5 smooth muscle tumors of uncertain malignant potential (STUMP) and 8 leiomyosarcomas (LMS), to investigate the diagnostic value of MIB-1 and p53 in uterine smooth muscle tumors.
RESULTS: The MIB-1 labelling index was low in ULs and their variants (mean 5.67+/-5.53), but it was increased in STUMPs (17.67+/-6.51) and markedly increased in LMSs (35.71+/-11.35). In ULs and their variants, no immunostaining for p53 was noted except in one case of BL, while 2 (40%) of 5 STUMPs and 3 (38%) of 8 LMSs showed positive reactions for p53. There were significant differences among leiomyoma, STUMP and LMS in the MIB-1 labelling index and p53 expression.
CONCLUSIONS:These results suggest that both abnormal expressions of p53 and a high MIB-1 labelling index are frequently associated with leiomyosarcoma. Our data also indicate that the classification system of Kempson and Hendrickson is well correlated with the MIB-1 labelling index.