Objective: Providing the consistency between the results from cytologic examination (Pap test) of cervical lesions with those of follow-up biopsies is an important quality control method. We investigated diagnostic difficulties and reasons in cytohistopathologic practice in this study.

Material and Method: We included 43 patients cytologically diagnosed as LSI L or HSI L between 2001-2007 with negative subsequent biopsy results.

Results: We were able to gain access to the cytological material of 37 cases and 9 of these received different diagnoses from the initial diagnoses. Re-evaluation of the biopsies provided a diagnosis of SI L in 9 of 43 cases.

Conclusion: The reason for the inconsistent histopathologic diagnoses was misinterpreting in 6 cases and microscopic sampling error due to the lack of serial cuts in 3 cases. We detected %21 false negatives on biopsies mostly as a result of misinterpretation. The squamocolumnar junction was not present in 11 cases that had previously been diagnosed as negative. In conclusion, serial cuts must be evaluated by an experienced pathologist specialized in gynecopathology in cervical biopsies with positive cytology results and the absence of the squamocolumnar junction must be reported.