New concept in diagnostic endometrial cytology: diagnostic criteria based on composition and architecture of large tissue fragments in smears.

Routine endometrial cytology was used instead of curettage as the first step in a morphological investigation of the endometrium in patients with postmenopausal bleeding. Premenopausal women with symptoms or signs indicative of premalignant or malignant disease were also studied using this method. Patients with alarming cytological findings were further investigated with curettage. Diagnostic criteria for endometrial cytology have not been fully established: new diagnostic criteria were used in this study, which were based on the composition and architecture of larger tissue fragments in the smears. The new criteria were especially useful for tackling diagnostic problems caused by variation in nuclear size. Two thousand six hundred and twenty five cytological investigations were conducted over three years (January 1981 to January 1984). Adequate material for diagnosis was found in 2520 specimens (96%). Diagnosis based on the cytology was negative--that is, not indicative of malignant or premalignant disease in 2378 cases (94%). Follow up studies in 1984 showed no false negative results. Adenocarcinoma of the endometrium was diagnosed in 31 cases, carcinoma or carcinoma in situ of the cervix in 11 cases, and carcinoma of the ovary in four cases, all confirmed by histological investigation. Of 20 cases reported as suspected carcinoma, 12 of these were verified. The cytological diagnosis of adenomatous hyperplasia showed a low sensibility: only ten of 50 histologically controlled cases could be verified after curettage.