The problem of stage Ia (FIGO, 1985) carcinoma of the uterine cervix.

The FIGO definition of stage Ia (microinvasive) carcinoma of the uterine cervix had been vague and caused continued confusion. In 1985 FIGO revised the definition of stage Ia by including measurements in the definition and it also subdivided stage Ia into stages Ia1 and Ia2. One hundred and eighteen of eight hundred and sixty patients with stage 0 to IIb carcinoma, who retrospectively satisfied the new FIGO definition of stage Ia, were reviewed with respect to depth of invasion, horizontal spread, number of invasive foci, vascular space involvement, pattern of invasion, incidence of lymph node metastasis, and clinical outcome. There were three potentially high-risk patients: one with pelvic lymph node metastases, one with parametrial metastasis, and the third with recurrence 23 months after initial treatment. It was pointed out that the border between stages Ia1 and Ia2 is very vague in the 1985 FIGO definition. It was proposed that a lesion with 3-mm or less stromal invasion and without vascular space involvement and confluency be defined as stage Ia1 and be safely treated with simple means.