A 40-years-old woman presented to the gynecologist with complaints of profuse vaginal discharge. The diagnosis of bacterial vaginosis is made based upon all of the following findings on microscopy, except:
**Core Concept**
Bacterial vaginosis (BV) is a common vaginal infection in women of reproductive age, characterized by an imbalance of the normal vaginal microbiota. The diagnosis of BV is primarily based on clinical criteria and microscopic examination of vaginal discharge.
**Why the Correct Answer is Right**
The diagnosis of BV is typically confirmed by the presence of clue cells, which are vaginal epithelial cells that are coated with bacteria, particularly Gardnerella vaginalis. The presence of clue cells is a key diagnostic feature of BV, and it is often accompanied by other clinical findings such as a fishy odor of the discharge and a thin, white or grayish discharge. The microscopic examination of vaginal discharge is usually performed using a saline wet mount or a Gram stain.
**Why Each Wrong Option is Incorrect**
**Option A:** While the presence of lactobacilli is a normal finding in vaginal discharge, it is not a diagnostic feature of BV. In fact, the diagnosis of BV is often associated with a decrease in lactobacilli and an increase in other types of bacteria.
**Option B:** The presence of white blood cells (leukocytes) in vaginal discharge is often associated with infections such as yeast infections or trichomoniasis, rather than BV.
**Option C:** The presence of yeast cells, such as Candida, in vaginal discharge is a diagnostic feature of a yeast infection, rather than BV.
**Clinical Pearl / High-Yield Fact**
The Amsel criteria, which include the presence of clue cells, a thin, white or grayish discharge, a pH of the discharge greater than 4.5, and a fishy odor of the discharge, are commonly used to diagnose BV.
**Correct Answer: D.**