Cannonballs in Pap Smears: Double Whammy of Bacterial Vaginosis and Associated Infections

Abstract

Introduction: Cannonballs are structures consisting of neutrophils adherent to epithelial cells, often seen in vaginal Pap smears of patients with trichomoniasis and chlamydiasis. We frequently observed these cannonballs in inflammatory Pap smears showing evidence of bacterial vaginosis. Objective: To study the association between cannonballs and bacterial vaginosis with associated infections in inflammatory Pap smears. Study Design: This was a retrospective study performed over a period of 6 months between April 2014 and September 2014. Three hundred consecutive Pap smears assessed during the study period were retrieved from the archives and studied. Results: A total of 280 smears were studied. Neutrophilic infiltrates were seen in 83.6%, cannonballs in 82.3%, and bacterial vaginosis in 70.7% of the smears. Cannonballs were found in 84.4% of the smears showing evidence of bacterial vaginosis with associated inflammatory infiltrates. There was a significant association between cannonballs and bacterial vaginosis (p = 0.0001). The odds ratio was 13.8 (95% CI: 7.2-26.2). Conclusion: The present study shows a significant association between cannonballs and bacterial vaginosis and associated vaginal infections.

Inflammatory cells in liquid‐based cytology smears classified as bacterial vaginosis

“…Beghini et al demonstrated that a decrease in Lactobacilli and/or lactic acid (plus the absence of leukocytes) results in lower vaginal neutrophil gelatinase‐associated lipocalin levels, while facilitating the growth of bacteria associated with BV. Therefore, BV is a condition associated with few or no leukocytes, although Krishnamurthy et al observed leukocytes in 70.7% of 280 Pap smears, which were diagnosed as BV. This was higher than our findings, but the authors did not quantify the leukocytes and collected cervical smears, vs.vaginal smears, which can influence leukocytes, as shown .…”

Significance of Reporting Cannon Balls in Diagnosing Bacterial Vaginosis Infection in PAP Smear

“…2 Cannon balls are neutrophils adherent to epithelial cells, often seen in vaginal Pap smears of patients with trichomoniasis, chlamydiasis and BV. 7,8 The identification of neutrophil alone is not sufficient to diagnose the presence of microorganisms in Pap smear. Neutrophil in the Pap smear are a nonspecific finding, particularly if they are low in number or if they are seen in the premenstrual and the menstrual phases.…”

“…A larger sample size will be better representation of entire population and it is a need in near future to provide the more accurate results. Murthy et al where cannon balls were found in 84.4% cases of BV 7. Likewise, Karani et al25 stated that Pap smears have moderate sensitivity in diagnosing BV.…”