The role of cytology in the diagnosis of periocular basal cell carcinomas.

The accurate diagnosis of eyelid tumors such as basal cell carcinoma (BCC) requires histological confirmation, usually obtained by biopsy. Cytology provides a rapid alternative that can yield a diagnosis during the initial outpatient appointment. The accuracy of this technique has been reported to be very good but its sensitivity in the diagnosis of periocular lesions is unknown. In order to assess the accuracy of cytology in eyelid lesions suspected clinically to be BCCs, the cytological and histopathological diagnoses were compared retrospectively in 20 lesions from 17 consecutive patients who underwent cytology followed by excision biopsy. The sensitivity of cytology for the diagnosis of BCC was 92% compared with 88% for the diagnosis of malignant tumor. The predictive accuracy was 75% for either diagnosis. This was compared with a second group of 26 clinical BCCs from 22 consecutive patients who had incisional biopsy and histological examination followed by excision with histological confirmation, in which case the sensitivity was 100% and accuracy 96%. It was concluded that cytology was sufficiently accurate to plan excision and reconstructive surgery, when a confirmatory tissue diagnosis can be made, but not sufficiently sensitive for conservative regimens such as radiotherapy because of the small risk of false negative diagnoses.