Cystocele (Answer: A)
The most likely diagnosis is cystocele, given the anterior vaginal wall bulging through the introitus in a postmenopausal woman with pelvic pressure symptoms and vulvar atrophy. 1
Clinical Reasoning
The key examination finding—mucosal bulging through the introitus—localizes the prolapse to a specific compartment. In pelvic organ prolapse, the location of the bulge directly indicates which structure has herniated:
- Anterior compartment prolapse (cystocele) presents as anterior vaginal wall bulging, which is what "mucosal bulging through the introitus" typically describes in the absence of other specifying features 1
- The anterior compartment is the most commonly affected site in pelvic organ prolapse, and imaging studies show the highest correlation between physical examination and diagnostic confirmation in this compartment (59.6-70% detection rate) 2
Why Not the Other Options?
Rectocele (Option B) would present as posterior vaginal wall bulging, not anterior bulging through the introitus 1. Patients typically report difficulty with defecation, need for splinting, or sensation of incomplete evacuation 2.
Enterocele (Option C) represents herniation of small bowel into the rectovaginal space and typically presents as apical or upper posterior vaginal bulging 1. This is a middle compartment defect that would not be the primary finding with simple "mucosal bulging through the introitus" 2.
Paravaginal defect (Option D) is a lateral support defect that contributes to cystocele formation but is not itself a distinct clinical entity that presents as bulging through the introitus 3. It represents a specific anatomic mechanism rather than the clinical diagnosis.
Supporting Context
- This 58-year-old postmenopausal woman has classic risk factors: advanced age and menopause, both established contributors to pelvic floor dysfunction 2
- Vulvar atrophy is an expected finding in postmenopausal women due to hypoestrogenic state and does not indicate a specific type of prolapse 4, 5
- The symptoms of pelvic heaviness and lower pelvic pressure are nonspecific manifestations of pelvic organ prolapse affecting approximately 25-33% of postmenopausal women 2
Clinical Pitfall to Avoid
Do not assume that all vaginal bulging is the same—the specific location (anterior vs. posterior vs. apical) determines the diagnosis and subsequent surgical approach 1, 3. Multi-compartment involvement is common, so comprehensive examination of all compartments is essential even when one defect is obvious 2, 1.