Curative surgery for placental site trophoblastic tumors

Abstract

Placental site trophoblastic tumors (PSTTs) are the least common form of gestational trophoblastic disease: only approximately 300 cases have been reported [1]. They can complicate any type of pregnancy, and the time between delivery and diagnosis can be long. Patients can present with vaginal bleeding, amenorrhea, or a uterine mass. The β human chorionic gonadotropin (β-hCG) concentration is usually moderate and much lower than in patients with choriocarcinoma [2]. PSTTs are particularly resistant to chemotherapy and need specificmanagement. When identified early, the prognosis can be favorable when complete excision is performed [2,3]. The aim of the present report is to present two PSTTs treated by hysterectomy with residual tumor noted on examination of the uterus. Written informed consent for publication was obtained from the two patients, and the present report was written with the approval of the institutional review board of Lille University Hospital, France. In October 2009, awoman aged 24 years presented to Lille University Hospital with vaginal bleeding. She had previously had one normal pregnancy and one spontaneous abortion. Her serum concentration of β-hCG was approximately 300 IU/L. Ultrasonography showed a uterine mass, and magnetic resonance imaging (MRI) revealed a rounded endometrial formation distorting the shape of the myometrium (Fig. 1A). A significant homogeneous enhancement was observed with gadolinium. In April 2010, a woman aged 35 years also presented with vaginal bleeding. She had had one previous normal pregnancy and one complete hydatidiformmole. Her β-hCG level was 21 IU/L. Ultrasonography showed a 13-mm endometrial thickening. Standard staging, including pelvic MRI, was negative, without uterine mass in the endometrium or myometrium. In both cases, PSTT was diagnosed after uterine curettage. Surgical hysterectomy was subsequently performed, after which the β-hCG levels returned to normal in both patients. Gross findings of hysterectomy showed a nodularmass in the uterus infiltrating themyometrium in patient 1 (Fig. 1B). Nomacroscopic lesionwas seen in patient 2 (Fig. 1C). Histological examination revealed the samemononuclear trophoblastic proliferation with admixed multinucleate cells separating myometrial fibers in both patients (Fig. 1D and E), extending to three-quarters of the myometrium in patient 1 and limited to the inner third of the myometrium in patient 2 (International Federation of Gynecology and Obstetrics stage I for both cases). The appearance of PSTTs on imaging varies. Themost frequent ultrasonographic abnormality is a focal echogenic myometrial nodule [4]. MRI typically shows a myometrial mass isointense to adjacent normal myometrium on T1-weighted images and isointense to slightly hyperintense on T2-weighted images. Inconstant prominent blood vessels have been shown to be related to the physiological vascular invasion of extra villous trophoblast. By contrast with PSTT, choriocarcinoma is always a highly vascular tumor. For endometrial carcinoma, MRI is also helpful for assessment of the depth of myometrial invasion and extrauterine disease spread. Nevertheless, imaging findings are not specific, and some PSTTs are undetectable, as in the second case presented here. Diagnosis is made on the basis of intermediate trophoblast proliferation growing in and infiltrating myometrial fibers. Therefore, intrauterine aspiration is insufficient; a uterine curettage is necessary. PSTTs grow slowly, tend to spread through the uterus and can involve the lymph nodes with late metastasis. Preoperative staging requires pelvic, abdominal, and chest computed tomography, and pelvic and brain MRI. The most effective treatment for non-metastatic disease is hysterectomy [2]. In a series of 55 PSTTs, only one hysterectomy International Journal of Gynecology and Obstetrics 130 (2015) 84–88