[1107] Individual Tumor Cell Apoptoses in Uterine Smooth Muscle Tumors

PPC Ip, KY Tse, ANY Cheung. University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, Hong Kong

Background: Individual tumor cell apoptosis (TCA) in uterine leiomyomas has not been specifically studied. There is relatively few information on their causative factors and the significance of their presence is uncertain. It has been suggested that tumors that have foci of TCA, but absence of atypia, mitotic activity or necrosis should be labeled as smooth muscle tumors of uncertain malignant potential (STUMP).
Design: Three hundred consecutive cases of uterine smooth muscle tumors other than leiomyosarcomas from the surgical pathology files of Queen Mary Hospital were screened for the presence of TCA. The clinicopathologic features and follow-up information were obtained. Immunohistochemical stains for p16, p53, MIB1 (ki-67) were performed on cases regarded as STUMP.
Results: Twenty-one cases (7%) of uterine smooth muscle tumors were found to possess TCA. Patient age ranges from 38 through 61 (median, 46). Twelve of the 21 patients (57%) had a history of drug usage (oral contraceptives and/or tranexamic acid). One patient was treated for ovarian endometriotic cyst and another for carcinoma of the cervix. The remainder all presented with symptoms related to uterine fibroids, including menorrhagia, urine frequency, abdominal mass or combinations thereof. Five were treated with myomectomy and the rest had total hysterectomy and bilateral salpingo-oophrectomy. Secondary changes found alongside the TCA include: infarct type necrosis (43%), early infarcts (19%), necrosis of an uncertain type (14%), myxoid/hyaline change (81%), hemorrhage (38%) and hydropic change (57%). Five cases (24%) had TCA unaccompanied by any necrosis. Three cases were diagnosed as STUMPs based on the presence of necrosis of an uncertain type and/or TCA, 1 was a leiomyoma with bizarre nuclei and 1 was a cellular leiomyoma. None of the STUMPs showed over-expression of p16, p53 or MIB1. Follow-up ranged from 1 to 64 months (median, 58). The follow-up for patients with STUMPs were 49, 60 and 67 months respectively. None of the patients had tumor recurrence.
Conclusions: TCA is an uncommon finding in uterine leiomyomas. Many of such cases also have secondary degenerative changes and are found in patients taking oral contraceptives and/or tranexamic acid. Although commonly coexists with infarct type necrosis, TCA found in isolation does not appear to be a worrisome microscopic feature.
Category: Gynecologic & Obstetrics

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 147, Wednesday Morning


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