Cytologic scoring of endometrioid adenocarcinoma of the endometrium

BACKGROUND: Endometrial carcinoma is one of the most frequent malignancies in the female genital tract, and its incidence has been increasing in Japan. Histologic grade is an important factor for organizing treatment strategies, including hormone therapy, and for predicting the prognosis of the patient. The objective of this study was to evaluate the applicability and usefulness of cytologic scoring in assessing the morphologic differentiation of endometrioid adenocarcinomas of the endometrium using endometrial smears. METHODS: Sixty-four endometrial cytologic samples of endometrioid adenocarcinomas of the endometrium were used in this study. All patients underwent endometrial cytology before hysterectomy, and the diagnosis was confirmed by histologic examination of the extirpated uterus. Each cytologic specimen was scored according to a scoring system established by the authors. The cytologic grade based on those estimated scores was compared with the histologic grade and clinicopathologic parameters, respectively. RESULTS: The cytologic grade (CG) was correlated positively with the histologic grade. A high cytologic score was correlated with p53 mutation and myometrial invasion and was correlated negatively with estrogen receptor and progesterone receptor status. The concordance rates of cytologic grade with well differentiated (Grade 1), moderately differentiated (Grade 2), and poorly differentiated (Grade 3) histologic grades were 83.3% (35 of 42 tumors), 9.1% (1 of 11 tumors), and 100% (11 of 11 tumors), respectively. The total concordance rate was 73.4% (47 of 64 tumors). The best cut-off value for distinguishing histologic Grade 1 from the others was a cytologic score of 17, representing a sensitivity of 83% and a specificity of 81%. For distinguishing histologic Grade 3 from the others, the best cut-off value was a cytologic score of 20, representing a sensitivity of 100% and a specificity of 83%. CONCLUSIONS: The cytologic scoring system studied for endometrioid adenocarcinoma was useful for predicting histologic grade and tumor malignant potential.