Annals of Tropical Pathology

: 2020  |  Volume : 11  |  Issue : 1  |  Page : 29--32

Cytolytic vaginosis: A common yet underdiagnosed entity

Shailja Puri 
 SRL Diagnostics, Shimla, Himachal Pradesh, India

Correspondence Address:
Dr. Shailja Puri
SRL Limited, Shimla, Himachal Pradesh


Objective: The objective of this study is to determine the incidence of cytolytic vaginosis among patients undergoing cervicovaginal cytology for vaginal discharge, pruritus, dyspareunia, and other symptoms. Cytolytic vaginosis is also known as Lactobacillus overgrowth syndrome or Doderlein's cytolysis. It is characterized by an abundant growth of Lactobacilli resulting in lysis of vaginal epithelial cells. Methods: A total of 308 women presented to gynecological outpatient department. All of the patients were subjected to Pap test with the help of cytobrush. The cervicovaginal smears were fixed in methanol, stained with papanicolaou stain, and studied under a microscope independently by two pathologists. Results: Of 308 patients, 190 (61.7%) had an inflammatory lesion and were negative for intraepithelial malignancy. Of 190 cases, 31 (16.3%) were diagnosed with cytolytic vaginosis based on the clinical and morphological features. Conclusion: Cytolytic vaginosis is a fairly common entity often misdiagnosed as candidiasis. Morphological features play an important role in identifying cytolytic vaginosis. The results of this study may contribute to reports in the literature indicating the importance of cytolytic vaginosis which is not included in the current Bethesda system for reporting of cervical cytology.

How to cite this article:
Puri S. Cytolytic vaginosis: A common yet underdiagnosed entity.Ann Trop Pathol 2020;11:29-32

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Puri S. Cytolytic vaginosis: A common yet underdiagnosed entity. Ann Trop Pathol [serial online] 2020 [cited 2021 Feb 28 ];11:29-32
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Vaginal discharge is one of the most common complaints encountered among women of reproductive age group. Infection with Candida, Trichomonas, and coccobacilli accounts for the majority of cases with vaginal discharge. Some of the patients presenting with vaginal discharge may be unresponsive to treatment with abovementioned infections. These patients may be suffering from cytolytic vaginosis. Cytolytic vaginosis (CV) is also known as Lactobacillus overgrowth syndrome or Doderlein's cytolysis. It is characterized by an abundant growth of Lactobacilli resulting in lysis of vaginal epithelial cells; and therefore, called cytolytic vaginosis.[1] The normal vaginal flora was first described by Doderlein as consisting of acid-producing Gram-positive, immobile, nonspore-forming anaerobes, now referred as Lactobacillus species. Healthy women of reproductive age groups are colonized by Lactobacillus. It is also suggested that the presence of estrogen and Lactobacillus are needed to achieve an optimal vaginal pH of 4.0–4.5. Lactobacilli produce lactic acid from glucose, keeping the vagina at an acidic pH. After puberty, glycogen is deposited in the vaginal epithelial cells under the influence of estrogen which is metabolized by vaginal epithelial cells to glucose. Lactobacillus converts glucose to lactic acid.[2] They occur in abundance in the late luteal phase and in pregnancy, prefer an acid environment, and are common among women using hormonal preparations (contraceptives and replacements) and in the premenarchal and menopausal age groups.[3] Lactobacillus has a protective role also. Some species of Lactobacillus produce hydrogen peroxide, which is toxic to various microorganisms. This may prevent overgrowth of organisms such as Escherichia coli, Candida species, Gardnerella vaginalis, and Mobiliuncus species. According to several studies, Lactobacilli builds up a barrier against candida overgrowth by blocking the adhesion of yeast to vaginal epithelial cells through competition for nutrients.[4]

In health, low number of Lactobacilli (five bacilli per ten squamous cells) is considered protective against candidiasis by blocking the adhesion of candida yeast cells to vaginal epithelial cells, through competition for nutrients.[5] Overgrowth of Lactobacilli may occur in individuals of reproductive age group by causing dissolution and damage to vaginal intermediate epithelial cells. It has been observed that in the luteal phase, there is a remarkable rise in the number of colonizing Lactobacilli. It has been claimed that Lactobacilli are more abundant in women with diabetes mellitus.[2]

The entity is included in the current Bethesda system for reporting cervical cytology, as “unsatisfactory for evaluation.” In these cases, the reason for “unsatisfactory smears” should be mentioned in the report. Awareness about this entity and its characteristic morphological features is necessary to avoid suffering and unnecessary medication of patients.


A total of 308 cases of cervical smears over a period of 1 year were received at our clinical laboratory from the gynecology outpatient department. The cervical smears were prepared using cytobrush. All smears were fixed in methanol, stained with papanicolaou stain, and examined independently by two pathologists.


Of 308 cases of cervical smears, 190 were inflammatory (61.7%). Out of inflammatory cases, 31 were of cytolytic vaginosis (16.3%). The most common presenting symptoms in patients with cytolyltic vaginosis were increased vaginal discharge and pruritus vulva. The age groups ranged from 24 to 61 years, with a median age being 39 years. The parity of patients ranged from P0+0 to P6+0. Of 31, 19 (61%) were in the luteal phase and this finding corroborates with the literature.[6] The colposcopic findings ranged from cervical erosion, vaginitis, vulvitis, and discharge [Table 1]. The cytological findings were increased in the number of Lactobacilli, a paucity of white blood cells, the presence of cytolysis, stripped or naked nuclei, and the absence of fungus, coccobacilli, or Trichomonas [Figure 1] and [Figure 2]. Based on the clinical and cytological features, these cases were diagnosed as cytolytic vaginosis with advise to repeat cervical smears after treatment.{Table 1}{Figure 1}{Figure 2}


Cytolytic vaginalis presents clinically with vaginal discharge, pruritus, dyspareunia, and vulvar dysuria. Cyclical increase in symptoms is observed in the luteal phase. CV is characterized by vaginal pH between 3.5 and 4.5. Microscopically, the papanicolaou-stained cervicovaginal smears show abundant Lactobacilli, paucity of pus/polymorphonuclear cells, bare/naked nuclei, cytoplasmic fragments, and the absence of fungal spores/hyphae, coccobacilli, or Trichomonas. The microscopic features of CV are based on a study conducted by Hu et al. to observe the morphological characteristic of vaginal discharge in patients with CV under the microscope.[6] The clinical features of CV are similar to vulvovaginal candidiasis (VVC); thus, it is important to exclude candidiasis by investigations. CV can be distinguished from bacterial vaginosis (BV) by pH measurement and whiff test. The pH in the case of BV is more than 4.5 and the Schiff test is also positive. The large number of Lactobacilli covering squamous cells can mimic clue cells seen in BV; however, it can be distinguished by careful examination. The key points of differentiation between CV, candidiasis, and BV are tabulated in [Table 2].{Table 2}

CV is not an uncommon condition; however, it is often misdiagnosed because it is confused with candidiasis. Many practitioners rely on their clinical judgment alone rather than investigations. Compounding the problem of misdiagnosis is that patients assume that their symptoms are caused by a yeast infection, which results in telephone requests for medication from their physicians instead of an office consultation.[7] Cerikcioglu and Beksacin their study of 210 women with vaginal discharge and other symptoms/signs of genital pathology, suggestive of VVC, observed that fifteen patients (7.1%) were diagnosed with CV. All of these cases were in the reproductive age groups of 25–40 years and five were in the luteal phase, with enhanced complaints of discharge and pruritus.[1] In another study conducted by Demirezen to detect the rate of CV in patients with symptoms resembling that of candidiasis and to distinguish them from candidiasis cases by examining of 2947 papanicolaou stained cervicovaginal smears. Fifty-four of 2947 patients (1.83%) were diagnosed as having CV based on cytological/morphological criteria.[8]

The treatment of CV is directed toward reducing the number of Lactobacilli by elevating vaginal pH. The vaginal pH is elevated by douching with sodium bicarbonate solution or suppository vaginally. Douches are carried out twice weekly for every 2 weeks. Douching solution is prepared by mixing 1–2 tablespoons of baking soda with four cups of warm water. A suppository is prepared by filling gelatin capsules with baking soda. Elevating vaginal pH resolves the symptoms by restoring the normal vaginal environment. If symptoms persist or worsen beyond 2–3 weeks after initiating treatment, reevaluation is required.[2]


The study emphasizes the need for the correct diagnosis of vaginal discharge wherein CV should be considered as a possible culprit. It is not as common as candidiasis or BV; however, it is sometimes confused with the former. A misdiagnosis can lead to patient suffering and unnecessary medication for other causes. Morphological features play an important role in identifying the possible cause of the vaginal discharge and cervicovaginal smears should be studied for all patients with vaginal discharge. The results of this study may contribute to reports in the literature indicating the importance of CV which is included in the current system for reporting of cervical cytology under “unsatisfactory for evaluation.” The reason for “unsatisfactory smears” should be mentioned in the report so that these patients can be treated correctly.

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