"atypical squamous cells of undetermined significance: a cytohistologic study"

although the diagnostic category of atypical squamous cells of undetermined significance (ascus) has been known since 1988, its use and appropriate clinical follow up and management still remains controversial. this study was carried out to evaluate the diagnostic value of ascus, using cytohistologic correlation. a retrospective review of archival materials in our cytology laboratory files was performed for cervicovaginal smears diagnosed as ascus from march 1999 to february 2002. in 8551 cervicovaginal smears examined, ascus was reported in 236 (2.76%) cases, with histologic follow up in 98 (41.2%). during the follow up period of patients with ascus, 51 patients (52%) had benign/reactive lesions, 43 patients (43.9%) were diagnosed as having a squamous intraepithelial lesion (sil), 2 (2.1%) specimen were insufficient and finally two cases (2%) proved to be invasive cervical carcinoma on histology. of cases diagnosed as sil, 22 (22.4%) were interpreted as flat condyloma, 9(9.1%) cervical intraepithelial neoplasia (cin) 1, 2 (2.1%) cin 1-2, 3 (3.1%) high grade sil, 6 (6.1%)basal cell abnormality of undetermined significance, and 1 (1%) had features of cin 1 in presence of severe inflammation. patients whose smears fall into the category of ascus may exhibit a spectrum of findings, ranging from benign/reactive lesions to frequent sil and rarely to invasive carcinoma. therefore, patients with a diagnosis of ascus justify careful follow-up and investigation.