Cytological analysis of early stage Ib carcinoma of the uterine cervix

Cytology is a useful technique in the diagnosis of cervical cancer. It is still difficult, however, to make a correct cytopathological diagnosis of early stage Ib cancer (cases with invasion of less than 5mm excluding stage Ia as defined by the criteria of the Japan Society of Obstetrics and Gynecology). The cytological specimens of 13 cases with stage Ia and 22 cases with early stage Ib (6 cases with invasion less than 3mm=Ib 1, 16 cases with invasion up to 5mm=Ib 2) were analyzed to clarify differences among the various stages. The incidences of multinuclear, malignant pair cell and nucleolus were similar among the 3 groups. Anisonucleosis, elongated nucleus and differentiative tendencies for cellular figures were prominent in cases with Ib 2. No tumor diathesis was observed in 11 of 13 cases with stage Ia (84.6%), whereas 10 of 16 cases (62.5%) with early stage Ib had apparent diathesis. Cellular clusters were not in evidence in 10 cases of Ia (69.2%) nor in 2 of Ib 2 (12.5%), whereas numbers of clusters exceeding 10 were observed in 0.0% and 25.0%, respectively. The cluster size tended to be large in Ib 2 and cluster diameters exceeding 0.3mm were found in 23.1% of Ia and 62.5% of Ib 2. We conclude that prominent anisonucleosis, elongated nucleus, differentiative tendencies and large clusters, over 0.3mm in diameter, numerous clusters and tumor diathesis are the distingushing features of stage Ib 2. It is nonethdess difficult to differentiate stage Ia from Ib 1.