T2-weighted sequences in the MR study of endometrial carcinoma and their histological correlation

The degree of myometrial involvement is one of the factors that most markedly affect the prognosis and mode of treatment of endometrial carcinoma in its early stages. Our objective is to assess the value of MR in detecting the degree of myometrial invasion in patients with low-grade endometrial carcinoma and correlated some features of the MR images with the histological findings. We performed a prospective study in 25 postmenopausal patients diagnosed as having endometrial carcinoma on the basis of Pap smear. Using a 0.5 Tesla MR, T1-weighted, T2-weigheted and PD axial, coronal and sagittal prohections were done in the uterus. Shortly afterwards, radical hysterectomy and pelvic lymphadenectomy were carried out and the MR findings were compared with the results of the histological study of the resected tissue. The following parameters were recorded at MR for the evaluation of the endometrial carcinoma: size of the uterus, endometrial thickness, presence or absence of a mas, cervical involvement, lymph node involvement and degree of myometrial invasion (more or less than 50% of the tickness): in the latter case, the junction was assessed when visible and the tumor-myometrium interface when it was not. The overall validity of MR in the detection of deep invasion was 80%, with a sensitivity of 80% and a specificity of 80%. The major errors invlved four cases of overstimation of the depth of the invasion. In two of them, the surgical specimens presented polypoid masses that distended the uterus, stretching out the myometrium, in another, the histological study disclosed a myoma accompanied by sites of adenomyomatosis; and the fourth case presented senile myometrial atrophy. MR is useful in the preoperative staging of endometrial carcinoma as it is capable of predicting the degree of myometrial invasion, upon which the lymphatic dissemination depends directly. This information is the basis for chroosing a more or less aggressive surgical approach and for deciding on the need for postoperative radiotherapy. (Author) 9 refs