Frequency and following study of uterine leiomyoma variants in patients having surgery at Charoenkrung-pracharak Hospital

Abstract

Background : The frequency of uterine leiomyoma variants and smooth muscle tumor of uncertain malignant potential (STUMP) are low. No previously study about them has been done at Charoenkrungpracharak Hospital and in Thailand. Their clinical behaviors are uncertain with some controversies regarding the prognosis including the risk of recurrence.

Objective : To investigate the frequency of uterine leiomyoma variants and STUMP and to compare the clinicopathological features and recurrence rate of these variants to typical leiomyoma (LM).

Design : A retrospective study.

Setting : Charoenkrung-pracharak Hospital, Bangkok Metropolitan Administration.

Subjects : One thousand and fifty-two patients with smooth muscle tumor of the uterus

Materials and Method : Patients with pathological diagnosis of smooth muscle tumor (SMT) of the uterus from January 1, 1999 to June 30, 2010 were searched. Those (660 patients) who had associated gynecologic malignancy were excluded. Collected clinicopathological datas were: age, menopausal status, symptoms, treatment, and follow-up time of the patients as well as location, size, color, and consistency of the tumors. The clinicopathological features and recurrence rate of these variants were compared to those of typical leiomyoma (LM) and leiomyosarcoma (LS).

Results : One thousand seven hundred and seventeen cases of SMT were identified. Six hundred and sixty cases were excluded due to their associated cervical, ovarian, or endometrial cancers. Out of the 1,052 SMT cases included in the study, we found 983 typical LM, 64 uterine LM variants which comprised of 41 cellular type, 12 atypical type, 11 mitotically active type and 5 cases of STUMP. The frequency of uterine LM variants and STUMPwere 6.08% and 0.47%. Mean age of the patients was 45.3 years. Most were premenopausal and presented with abnormal uterine bleeding. Different features of these variants /STUMP from typical LM were: larger size, softer, non-white, and submucous in location. All 69 patients with uterine LM variants and STUMPS survived without any evidence of recurrence or death after a median period of follow-up of 26 months (ranged, 1 - 120 months).

Conclusions : The frequency of uterine LM variants and STUMP are 6.08 and 0.47% , respectively. The most common variants among them is cellular LM. All patients with these rare tumors have good prognosis without any recurrence and are alive.