American Board of Internal Medicine (ABIM) Certification Practice Exam

What are clue cells indicative of in a microscopic examination?

1. Gonorrhea

2. Bacterial vaginosis

3. Candidiasis

4. Trichomoniasis

The correct answer is: Bacterial vaginosis

Clue cells are a specific finding on microscopic examination of vaginal secretions and are indicative of bacterial vaginosis. These cells are characterized by their appearance; they are vaginal epithelial cells that become coated with bacteria and lose their typical, distinct outlines. This alteration in appearance occurs due to an imbalance in the normal flora of the vagina, where there is a predominance of anaerobic bacteria relative to lactobacilli. Bacterial vaginosis is the most common cause of abnormal vaginal discharge and is associated with a number of clinical features, including a fishy odor, particularly after sexual intercourse or during menses. The presence of clue cells helps microbiologists and clinicians make a diagnosis of bacterial vaginosis during microscopic analysis because they reflect this dysbiosis, distinguishing it from other conditions causing vaginal irritation or discharge. Other options reflect different conditions that do not include the presence of clue cells. For instance, gonorrhea and trichomoniasis are associated with different microscopic findings and may present with various symptoms, but they do not lead to the formation of clue cells. Candidiasis typically shows yeast forms or pseudohyphae in the microscopic examination, but not clue cells. Hence, the presence of clue cells is a hallmark finding of bacterial vaginos