Background The Papanicolaou (Pap) smear is the most successful screening test for carcinoma of cervix, mainly as a result of its simplicity, low cost, low false-negative rate and its early detection of preneoplastic lesions. It is also used to diagnose several infectious agents that manifest with specific cytologic features.
The diagnoses of candida, trichomonas, herpes simplex virus, HPV and bacterial vaginosis can be reliably rendered on Pap smears.
Conventional pap smear (CPS) has its limitations. False negatives in CPS may be related to inadequate sampling, inadequate transfer of the sample onto the glass slide or deficiencies in the microscopic assessment of the slide. To overcome these problems, a new slide preparation method namely the Manual Liquid Based Cytology (MLBC) was introduced, where cells are uniformly dispersed by a membrane, from a suspension of cells in a polymer solution.
MLBC helps in detecting number of infestations like Candida, Leptothrix, HPV with koilocytic atypia and bacterial vaginosis, as observed by many authors and us also.
MLBC, which we are following is inexpensive, cost effective method which we have adapted and are comparing it with CPS for its adequacy and utility. The other advantages, is that the residual specimens can be used for ancillary testing like immunocytochemistry by cell block preparation.
Results Number of cases of bacterial vaginosis diagnosed by CPS were 8, LBC 9 and cell block were zero. trichomonas were 4, by CPS and LBC,2by cell block., herpes was 1 by all three methods,inflammatory (NILM) cases were 22 by CPS,26 by LBC,12 by cell block. Inadequate smears were 5 by CPS, NIL by LBC,25 by cell block
Conclusion CPS and LBC with cell block are useful methods in detection of non neoplastic conditions of cervix.
LBC has increased the diagnostic accuracy by 13% in our study.
- cell block
- conventional pap smear
- liquid based cytology