Differential Diagnosis for Vulvar Lesions
- Single most likely diagnosis
- Condyloma acuminata (Genital warts): The patient's history of multiple sexual partners and the description of the lesions as multiple, nontender, fleshy, verrucous growths clustered at the vestibule of the vulva and over the labia majora are highly suggestive of condyloma acuminata, which is caused by low-risk human papillomavirus (HPV) types 6 and 11. The fact that she had negative testing for high-risk HPV last year during cervical cancer screening further supports this diagnosis, as high-risk HPV types are more commonly associated with cervical dysplasia and cancer rather than visible genital warts.
- Other Likely diagnoses
- Squamous cell carcinoma in situ or vulvar intraepithelial neoplasia (VIN): Given the patient's history of atypical squamous cells of undetermined significance (ASCUS) on cervical cancer screening and the presence of friable, bleeding lesions, there is a concern for a precancerous or cancerous process. However, the primary presentation and description lean more towards a benign condition like condyloma.
- Molluscum contagiosum: This is a viral infection that can cause small, pearly, or flesh-colored lesions. While it's less likely given the description of the lesions as verrucous and the patient's sexual history, it remains a consideration.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Invasive squamous cell carcinoma of the vulva: Although less likely given the patient's age and the description of the lesions, any vulvar lesion that is friable and bleeds on manipulation warrants a biopsy to rule out invasive cancer.
- Syphilis (secondary): Given the patient's past exposure to a partner with syphilis, although she was not diagnosed with it herself, secondary syphilis can cause a wide range of skin manifestations, including condyloma lata, which are highly contagious, flat, broad, moist papules in the anogenital area. However, these are typically not described as verrucous or friable.
- Rare diagnoses
- Lichen sclerosus: An autoimmune condition that can cause white, patchy skin that's thinner than normal, which may result in tearing or bleeding. It's less likely given the description of the lesions as fleshy and verrucous.
- Vulvar melanoma: A rare but aggressive form of skin cancer. While any new or changing skin lesion in the vulvar area warrants concern for melanoma, the description provided does not strongly suggest this diagnosis.